Review ArticleBehavior of PMMA Denture Base Materials ContainingTitanium Dioxide Nanoparticles A Literature Review

Mohammed M Gad 1 and Reem Abualsaud 2

1Lecturer Department of Substitutive Dental Sciences College of Dentistry Imam Abdulrahman Bin Faisal UniversityPO Box 1982 Dammam 31411 Saudi Arabia2Assistant Professor Department of Substitutive Dental Sciences College of Dentistry Imam Abdulrahman Bin Faisal UniversityPO Box 1982 Dammam 31411 Saudi Arabia

Correspondence should be addressed to Mohammed M Gad mmjadiauedusa

Received 14 November 2018 Revised 22 December 2018 Accepted 2 January 2019 Published 17 January 2019

Academic Editor Wen-Cheng Chen

Copyright copy 2019 MohammedMGadandReemAbualsaudThis is an open access article distributedunder theCreativeCommonsAttribution License which permits unrestricted use distribution and reproduction in any medium provided the original work isproperly cited

Titanium dioxide nanoparticles (TiO2NP) have gained interest in the dental field because of their multiple uses in addition to their

antimicrobial effect One of the applications in dentistry involves the incorporation into poly methyl methacrylate (PMMA) resinHowever there is a lack of evidence on their effects on the behavior of the resulting nanocompositeTherefore the present reviewaims to screen literatures for data related toPMMATiO

2nanocomposite to figure out the properties ofTiO

2nanoparticlesmethods

of addition interaction with PMMA resin matrix and finally the addition effects on the properties of introduced nanocompositeand evidence on its clinical performance Regardless of the latest researchprogress of PMMATiO

2nanocomposite the questionable

properties of final nanocomposite and the lack of long-term clinical evidence addressing their performance restrict their wideclinical use A conclusive connection between nanoparticle size or addition method and nanocomposite properties could not beestablished

1 Introduction

The numerous advantages of poly methyl methacrylate(PMMA) make it the most dominant polymer used asdenture base material The ease of processing low cost lightweight stability in the oral cavity and aesthetic properties areof these advantages [1] However this material is not ideal inevery aspect PMMA resin denture base material has poorsurface properties and weak mechanical properties includingimpact and flexural strengths [2] Therefore resins shouldbe reinforced using different materials to enhance theirproperties Recently nanotechnology invaded the dental fieldand initiated investigative research projects to explore thepossible applications and expected benefits within dentistryIt is of paramount importance to know the science behind thisnanotechnology to know how to utilize it to our advantagePolymeric nanocomposites are made of polymer matrix andfiller at the nanoscale [3] Literature shows that nanoscalereinforcing agents produce new mechanical and physical

properties which create a new class of nanocomposites [4]In dentistry many attempts have been made to create animproved version of PMMA with the addition of differentnanosized fillers [5] The properties of the new compositematerial depend on the nature of the added nanoparticlestheir size and morphology [6]

The science and applications of nanotechnology are con-stantly evolving as we witness new products being introducedinto themarketThis comeswith great responsibility to insurethe safety efficiency and applicability of such new tech-nologies Although nanomaterials generally offer superiorproperties their mechanical properties fall short in compar-ison to pure materials Lately worldwide research showedseveral advancements in the nanocomposite field after theextensive research on mechanical and physical propertiesof these nanocomposites [7] Different nanoparticles havebeen incorporated into the polymer matrix Among theseis TiO

2NP with its unique properties [7 8] The literature

investigated the effect of TiO2NP on some properties of

HindawiInternational Journal of BiomaterialsVolume 2019 Article ID 6190610 14 pageshttpsdoiorg10115520196190610

2 International Journal of Biomaterials

PMMA But a comprehensive study on the overall per-formance of PMMA nanocomposite was not observed Inaddition to that the relation between final properties of thecomposite and the actual structure is not available One ofthe goals of the present study is to review the effectiveness ofTiO2NP addition to PMMA for dental applications It also

seems necessary to determine the best percentage of fillerrequired to improve the properties as well as the method ofreinforcement to control future applications

Up to November of 2018 database search on Googlescholar PubMed and Scopus was conducted using thekey words ldquoDenture base Polymethylmethacrylate (PMMA)TiO2nanoparticles Physical propertiesrdquo Forty-eight articles

were found (Figure 1) Only 21 articles written in Englishlanguage were included where the titanium nanoparticleswere incorporated into PMMA denture base material Thetwenty-seven excluded articles did not fulfill the inclusioncriteria Few of the excluded articles were investigatingthe effect of surface coating with titania layer on physicalproperties (6 articles) and three others used microsizedtitania particles Other excluded articles were investigatinga mixture of two nanofillers (ZrO

2TiO2) (Fe

2O3TiO2)

(2 articles) the addition of barium titanate as a filler (3articles) the addition of titania nanotubes (1 article) micaor zirconiaABW (Aluminum borate whiskers) reinforceddenture base acrylic (2 article) gallates modified titaniumnanoparticles (1 article) and PMMA not used for denturebases (3 articles) Two excluded papers lacked full experi-mental data three papers were reviews and one paper wasnot in English language The selected articles were reviewedto extract all data related to PMMATiO

2nanocomposite

and to figure out the properties of TiO2NP method of

addition interaction with PMMA resin matrix effects on theproperties of newly introduced nanocomposite and finallyevidence on their clinical performance

11 Properties of1198791198941198742NP TiO2NPhas proved to have antimi-crobial properties Moreover it is a cheap biocompatiblematerial chemically stable free of toxicity resistant to cor-rosion with high strength and high refractive index [8 1823 30] Furthermore the literature showed that even theslight addition of TiO

2NP reinforcing agent to a polymeric

material affects the electrical optical chemical and physicalproperties of the resulting hybrid material [9 31]

Its photocatalytic ability promoted it to be known as anantimicrobial agent encouraging its addition to biomaterials[11 12 20 23 25] TiO

2NP have been found effective against

a wide range of microorganisms including gram-positiveand gram-negative bacteria fungi and viruses [11 23 25]The antimicrobial effect could be attributed to the surfaceproperties and structure of the nanoparticles includingnanocrystalline TiO

2 hydrophilic surface effect infrared

reflectivity and noncontact antimicrobial activity ThereforeTiO2NP have been recommended as filler in polymeric

materials [24]

12 Methods of PMMA1198791198941198742 Nanocomposite PreparationResulting properties of the hybrid material (PMMATiO2NP) will depend on the dispersion of the nanoparticles

within the matrix which is directly related to the addedamount [9] To achieve good dispersion of nanoparticleswithin polymers different methods of TiO

2NP addition

were suggested It is either added to acrylic powder ormonomer The addition of TiO

2NP to acrylic powder was

suggested where the required percentages were weighed andthoroughly mixed with acrylic powder To attain a uniformmixture and homogenous distribution of TiO

2NP ultrasonic

mixer mortar and pestle high-energy ball milling andsilanization of particles were all employed in which ballmilling seemed to be the most effective method [16 19 21ndash23] In another method TiO

2nanoparticles were mixed with

the acrylic powder up to 20 min in an amalgamator to obtaina homogenous mix [15 21] Others mixed the nanoparticleswith resin powder by hand to create the desired fillerpowderratio [13 14]

Addition of TiO2NP to liquid monomer is another

method of filler incorporation within acrylic resin [22]Investigators added nanoparticles to acrylic monomer toprepare monomerTiO

2NP in different concentrations To

insure uniformity ultrasonic dispersion was done [10 24]Themonomer containingNPwas sonicated for 60min beforemixing with PMMA powder [32] Others were sonicatedusing a probe at 120 W and 60 KHz for 3 min to preventnanoparticles agglomeration and insure homogeneity of themixture [18 25]

An additional method called twin-screw extraction pro-cess was developed to disperse the particles into the PMMA[9 33 34] TiO

2NP was mixed with the acrylic and extruded

using ZSK-25 twin-screw extruder at 210∘C and screw speedof 250 rpm Nanocomposite granules were then dried at 80∘Cfor 2 h using dryer unit of injection molding machine [34]

Hence the properties of nanocomposites depend on theinteractions between the polymer matrix and the filler sug-gesting the importance of functionalized TiO

2NP [35 36] As

revealed by a previous study PMMA nanocomposite basedon functionalized TiO

2NP demonstrated better mechani-

cal and physical properties [30] One reported method ofsilanization used 100 ml of ethanol solution (70 vol) withadjusted pH of 45 through titrating with 999 acetic acidFollowing that silane-coupling agent (TMSPM) was addedto ethanol solution and mixed A hundred grams of TiO

2NP

were added to TMSPM-ethanol solution and mixed for 20minutes followed by probe sonication for 30 minutes Themixture was then left to dry for 14 days and the resultingpowder was a silanized TiO

2NP [18 37] Others modified

the titania nanoparticles using methacrylic acid (MA) bydispersing 10 g of nanoparticles into 250ml iso-propanol and125 ml of MA into 80∘C ultrasonic bath for 8h The resultingcompound was dried at 85∘C after infiltration and washing[14]

13 Behavior of 1198791198941198742NP toward PMMA In addition toNP size and shape its interaction with PMMA matrix isconsidered a main factor of reinforcement effectivenesswhich depends on the surface characterization of the NPChatterjee (2010) studied the interaction between PMMAand TiO

2NP and found that they interact chemically and

physically [9] The TiO2NP can react with -COOR group

International Journal of Biomaterials 3

Search on PubMed - Google scholar - Scopus

bull 48 Articles found

27 Articles were excluded

bull 6 articles - studied the effect of surface coatingbull 3 articles - used micro-sized titania particlesbull 3 articles - studied barium titanatebull 3 articles - did not use PMMA not for denture basesbull 3 articles - were reviewsbull 2 articles - studied a mixture of nano-fillersbull PMMAreinforcedmicaandABW2ZrOstudied-articles2

as base materialbull 2 articles - lacked full databull 1 article - studied nano-tubesbull 1 article - studied gallate modified particlesbull 1 article - was in Chinese language

21 Articles were included

bull Used PMMA for denture basesbull nano-sizethein2TiOUsedbull Studied physical mechanical chemical anti-microbial

electrical or thermal propertiesbull Written in English

Figure 1 Study design

of PMMA polymer in two different ways One way is theformation of H-bond between carbonyl group (-C=O) andsurface hydroxyl group (-OH) of TiO

2NP The other way is

the binding of TiO2NP with two oxygen atoms of -COOR by

a bidentate coordination to Ti4+ cation [9] When TiO2NP

come to the surface they form crosslinks with PMMA [9] Asthe amount of TiO

2NP loading within the PMMA increases

this bonding also increases All this is possible because ofthe hydroxyl group on the surface of TiO

2NP and the -

C=O (Carbonyl) -OH (Hydroxyl) -COOH (Carboxyl) and-COOR (Ester) groups in the polymer matrix The crosslinking has been confirmed by Fourier-transform infraredspectroscopy (FTIR) [22 33]

The dispersion of the TiO2NP within the matrix hin-

ders polymer chain movements due to the strong adhesionbetween the TiO

2NP and PMMA As a result better modulus

is seen with TiO2NP-PMMA composite materials [9] Other

investigators reported increased stiffness of the compositematerial and decreased PMMAmobility [19]Thismay be dueto the large interface of TiO

2NP when wrapped in PMMA

which possesses a smaller dielectric coefficient There will bea strong electric interaction between them resulting in anelectric dipole layer at the nanoparticle surface In terms of

the atomic bonding the origin of the nonlinear refractiveindex may be due to the hyperpolarizability of Ti-O pairs [2138] Moreover the addition of spherical nanoscale particles iscapable of filling the interpolymeric spaces which was foundto enhance the polishability of the material [15]

14 Properties of PMMA1198791198941198742 Nanocomposite As men-tioned earlier PMMA is the most predominant polymer-based material for dentures However its mechanical andsurface properties are low [39] The addition of any materialto improve the antimicrobial properties of the PMMA shouldnot have an adverse effect on the mechanical propertiesIn reverse it is highly preferred to add a material that willimprove both biological and mechanical properties [34]TiO2NP is commonly used as a coloring agent and filler It

is capable of increasing the toughness of polymers producinga composite material with superior properties [40] With theadded antimicrobial property it is incorporation into PMMAresins is extensively used in oral removable appliances [41]Therefore the properties of the nanocompositewere screenedin this review to evaluate the reliability of TiO

2NP as

an additive to improve the performance of PMMATiO2

nanocomposite denture base material

4 International Journal of Biomaterials

141 Antimicrobial Activities TiO2NP were found to have

an intrinsic antimicrobial property due the production ofcytotoxic oxygen radicles [26] TiO

2NP are ideal additives

because of their nontoxicity and chemical stability Howeverunder certain conditions they have an antimicrobial ability[41] When they are exposed to UV-light in the presenceof oxygen and water they decompose and oxidize othercompounds organic and inorganic Therefore they canbe considered as antimicrobial additive [41] FurthermoreTiO2NP had the ability to inhibit the adherence of cariogenic

bacteria in planktonic phase as well as in later phases ofbiofilm formation The addition of TiO

2NP to PMMA resin

used for dentures or other oral appliances will have a positiveeffect against microbial colonization [42]

Anehosur et al (2012) found that the addition of 3wt TiO

2NP to PMMA produced a positive antimicrobial

effect It had the ability to reduce microbial number whichprevents quorum sensing thereby halts plaque formationon PMMATiO

2nanocomposite surface [11] Due to the

photocatalytic property againstmicroorganisms patients willbe able to maintain the hygiene of their dentures easilyby exposing them to solar energylight sources to activatethe TiO

2NP [11] On the same way Alrahlah et al (2018)

reported a 50 and 90 decrease in bacterial cell attach-ment of E faecalis and P aeruginosa respectively with themere addition of 3 TiO

2NP [43] Likewise Totu et al

(2017) investigated the effect of incorporating TiO2NP into

a 3D-printed PMMA denture in an attempt to improvedenture antimicrobial characteristics and found that even thesmall addition of 04 of TiO

2NP to PMMA resulted in a

nanocomposite that prevented the colonization of microor-ganisms and further formation of biofilm [24] As a resultTiO2NP could be incorporated into denture PMMA resin to

successfully fabricate antimicrobial dentures [24] The largeactive surface area of the nanoparticles compared to theirsmall size makes them highly effective in low percentagesof addition It was found that as low as 04 1 and 25TiO2NP inhibited the growth of Candida As reported in

the literature TiO2NP caused a halt in the cellular enzymes

and increased cell wall permeability causing cell death[44]

Few studies reported that the addition of asmuch as 5wtTiO2NP to the PMMA is needed to achieve the antimicrobial

effect [45] However with this addition structural decompo-sition and material weakening may occur [26]

142 Surface Properties Surface microtopography of thedenture is a very important feature inmicrobial adhesion andplaque formation and subsequently denture stomatitis

(1) Surface Roughness Denture wearers have high prevalenceof poor oral health This is mostly caused by the surfacecontours of the dentures and the irregularities of the oralmucosa [45] Many factors were found to have an effect onthe surface roughness (Ra) of denture bases one of whichis the reinforcing material of the acrylic resin [46] Alwanand Alameer (2015) found an increase in surface roughnesswith the addition of 3wt of TiO

2NP to PMMA denture

base material and attributed this increase to the presence ofnanoparticles on the surface of specimens [18]

To establish a relation between contact angle (wetting)and the amount of TiO

2NPfiller in the PMMAresin Hashem

et al (2017) found that it is dependent on filler amountThe addition of 1wt TiO

2NP led to a reduction in surface

wetting while the addition of more filler improved wettingThis finding confirms the effect of fillers on the surfaceof composite material compared to the pure counterpart[22]

While few investigations weremade on surface roughnessof PMMATiO

2nanocomposite a significant increase was

reported compared to pure PMMA [18] As the surface getsrougher and Ra values increase the surface area increasesmeaning more sites are available for microbial adhesion andcolonization One of the most common organisms to beharbored on the surface of acrylic denture bases isC Albicans[47] Studies have reported that the surface roughness ofa denture should not exceed 02 120583m [45] Although thereis a direct relation between surface roughness and candidaadhesion (increased roughness increases candida adhesion)the reduction in candida count confirms the antifungalproperties of TiO

2NP

(2) Hardness Reports have confirmed that TiO2NP im-

proved the hardness of heat cure PMMA [10 18] Xia etal (2008) attributed the increase in surface hardness totwo factors proper filler content and use of silane-couplingagent which increases the bonding between filler and resinmatrix [48]The effect on surface hardness was detected withadditions of TiO

2NP as low as 1 [21] In another study

investigating the addition of 05 1 and 2 hardnessvalues were found to increase with the addition and thehighest values were seen with 2wt TiO

2 Mosalman et al

(2017) related this to increased number of bonds betweenmatrix and fillers which requires more energy to break thesebonds [49] Hashem et al (2017) reported an increase inhardness values that reached 20 30 and 34 more thanpure PMMA with 1 2 and 3 TiO

2NP respectively This

was explained by the increase in material stiffness due topresence of rigid particles within the matrix in addition toreduction of matrix mobility [22]

Alwan and Alameer (2015) concluded that 3 additionof TiO

2caused a significant increase in surface hardness

compared to pure PMMA [18] while Ahmed et al (2016)suggested the need of adding 5 TiO

2NP to increase surface

hardness of conventional and high impact heat cure acrylicresin to remarkable values [19] More recently Alrahlah et al(2018) confirmed the increase in surface hardness of up to35 with 3 TiO

2NP addition The values of the hardness

measurements were higher at the surface of the compositeresin and decreased as we move inward toward the core ofthe material suggesting higher crosslinking at the surface[43] Regarding selection of the most appropriate concen-tration of filler for inclusion within denture resin results ofmulticriteria decision making (MCDM) method suggestedthat a filler content in the range of 2wt would create acomposite material with improved mechanical propertiesincluding surface hardness [34]

International Journal of Biomaterials 5

143 Mechanical Properties

(1) Flexural Properties During function oral appliancesincluding dentures are exposed to a magnitude of deformingstresses and any factor that increases the deformation of thedenture base may lead to fracture [17] One of the factorsthat may change the amount of denture deformation is theadditive into the PMMA resinThe effect of TiO2NP additionon flexural strength of PMMA is partially dependent onthe type of acrylics and the concentration of nanoparti-cles [19] In 2013 Sodagar et al investigated the effect ofadding 05 and 1 TiO2NP into PMMA and reporteda decrease in flexural strength PMMA containing 05wtshowed the lowest values It was concluded that there isan inverse relation between the concentration of the fillerand the flexural strength of reinforced PMMA [12] Hanet al (2008) reached the same conclusion and related theresults to agglomeration of particles within the matrix whichmakes them stress concentrations areas [50] Other studiesalso reported a reduction in flexural strength [13 19 32]and modulus of elasticity [51] with the addition of TiO

2NP

Hamouda et al (2014) found that TiO2NP caused a reduction

in flexural strength with no change in flexural modulus [13]In the same token Nazirkar et al in (2014) were exploringthe effect of adding TiO

2NP into heat cure acrylic resin on

antimicrobial properties and reported an adverse effect onflexural strength of the final product [32]

In contrast to previous studies superior flexural proper-ties were reported with different concentrations of TiO

2NP

added to PMMA than those of normal PMMA [10 18 21 52]This improvement may be attributed to the effect of silaniza-tion of TiO

2NP [18] or the good dispersion of fillers within

the matrix which improves modulus transverse strengthand ductility [18 52] Hashem et al (2017) found that with05ndash3wt TiO

2NP addition flexural strength and modulus

increased Moreover they suggested that reinforced PMMAcould offer superior chemical and mechanical propertiesmaking it a better option for dentures than pure PMMA resin[22] On the same way Rashahmadi et al (2017) found thatthe mere addition of 05 TiO

2NP improved the flexural

strength and Youngrsquos modulus by 4 Based on MCDMresults TiO

2NP addition to PMMA is an excellent option

for improving properties of PMMA for dental applicationsespecially in 2wt concentration [34] In a recent studyby Karci et al (2018) [16] different types (heat- auto- andmicrowave polymerized) of acrylic mixed with 1 3 and5 nanotio2 were used to test the flexural strength of theresulting composite That study came to a conclusion thatthe addition of 1 TiO

2NP to heat- and autopolymerized

acrylic could improve the flexural strength while it remainedunchanged with 3 TiO

2NP and decreased with 5 for all

types of acrylicThiswas explained by the increase in agglom-eration of nanoparticles at higher addition percentages

In a study by Mosalman et al (2017) various percentagesof TiO

2NP (05 1 and 2wt ) were added to pure PMMA

and found that the flexural strength of all groups stayedunchanged Sampleswith 05wtTiO

2NP showed only 375

improvement in flexural strength compared to pure PMMAYoungrsquos modulus for all groups was improved with the

highest value seen in samples containing 2wt TiO2NP

[49]

(2) Impact Strength With regard to impact strength theaddition of TiO

2NP to heat cured acrylic resin resulted

in a positive effect compared to pure PMMA [18] Studieshave confirmed this finding with different concentrationsof TiO

2NP including 1 [19 23] 2wt[34 49] and 3wt

[25] The same finding was reported after the addition ofsilanized TiO

2NP [53] The detected increase in impact

strength was justified by good bonding between PMMAmatrix and TiO

2nanofillers These fillers reside in small

voids between polymer chains and result in slow segmentalmotion Also they provide large surface area due to theirsmall size which helps in energy dissipation [25] Otherssuggested that the nanofillers in the acrylic resin toleratemost of the applied load while the resin matrix helps instructural integrity and load distribution which eventuallyinhibits crack propagation [23]

(3) Tensile Strength Shirkavand and Moslehifard (2014)investigated the effect of 05wt 1wt and 2wt TiO

2NP

on tensile strength of PMMA base resins and found that thetensile strength of nanocomposite was the highest with 1wtTiO2NP and the improvement was 35 more compared to

pure PMMA However further increase in TiO2NP content

led to an adverse effect [15] due to clustering of TiO2NP

The fillers work as impurities and act as defects and stressconcentration centers [15 49] The same results were alsoreported by Ghaheremani et al (2017) [23] The increase intensile strength is probably attributed to the fact that follow-ing the incorporation of nanoparticles into acrylic powderthe applied load is mainly tolerated by these nanoparticles

Contrary to previous studies Chatterjee in 2010 foundthat nanocomposite with filler content as high as 5wt and15wt had a 59 and 95 increase in tensile modulusrespectively compared to that of pure PMMA [9] This wascaused by the strong adhesion between TiO

2NP and PMMA

The applied load is transferred through these interfacialsurfaces to the strongest material that is the nanoparticles [9]

144 Color Stability It is noteworthy that the reinforcingfiller material should ideally improve the mechanical proper-ties without causing an adverse reaction to the aesthetics [2541] TiO

2NP have whitish color therefore the appropriate

percentage of this additive that fulfills the aforementionedrequirement should be considered An objective evaluation ofthe color change is usually done using a spectrophotometerwhere the difference between light absorption between dif-ferent samples is calculated [28] Aziz in 2018 evaluated thecolor change after adding 3wt of TiO

2NP and found that

the amount of light absorbed increasedmaking the reinforcedspecimens more opaque compared to pure PMMA Thischange was due to the presence of TiO

2NP within the

matrix which absorbs more light than polymer matrix duehigh atomic number [25] Further studies are required todetermine the proper TiO

2NP percentage needed to attain

a PMMATiO2nanocomposite with superior properties and

acceptable aesthetics

6 International Journal of Biomaterials

145 Water Sorption Solubility and Porosity Conventionalacrylic resins have voids and porosities that allow watermolecules exchange which could be the leading cause forwater sorption and solubility [18]The nature of denture resinmaterial allows it to absorb water which acts as a plasticizerand affects the material dimensional stability and denturedurability [41]Thewatermolecules force themselves betweenpolymer chains move them apart create internal stressesand result in crack formation [29] As reported by Alwan andAlameer [18] the addition of TiO

2NP to heat cure acrylic

resin decreases water sorption and solubility significantlycompared to pure PMMA Torres et al (2011) concludedthat PMMA-TiO

2-Fe2O3nanocomposites had lower sorption

and porosity values compared to pure PMMA but similarsolubility levels However the solubility levels were originallylow which is important to prevent the adverse effects on oralstructures or polymer functions [41] Also as thematerial getsmore homogenous it becomes less soluble with lower watersorption levels [29]

Therefore the addition of TiO2NP fills the microvoids

and polymer interstitial spaces decreasing the ability ofcomposite material to absorb water In addition to thatTiO2NP are insoluble in water and these particles partly

replace the hydrophilicmatrix which decreases water uptakeThe use of silane-coupling agent in silanization process ofTiO2NP could lead to a reduction in the amount of water that

reaches the inner layers of polymer matrix [18]

146 Thermal Properties The addition of 3 TiO2NP to

PMMA had no effect on thermal conductivity [25]The glasstransition temperature (Tg) test is done to understand thethermal stability and determine the temperature at whichthe material starts to degrade As the percentage of TiO

2NP

increases the Tg of nanocomposite increases linearly up to75wt TiO

2 Pure PMMA is stable up to 134∘C (1 weight

loss) while PMMA2wtTiO2and PMMA5wtTiO

2are

stable up to 154∘C and 180∘C respectively Tg was improvedby 15ndash34 with 2ndash5 addition of TiO

2NP respectively

However further addition of TiO2NP caused a decrease in

thermal stability [33] Another study by Safi (2014) reportedthe positive effect of TiO

2NP addition on the Tg temperature

of acrylic resin [51] In a recent study [43] authors evaluatedthe effect of adding 1 2 and 3 TiO

2NP to PMMA on

thermal behavior and found a slight effect on Tg degradationtemperature and rate

Chatterjee (2010) in another study reported that theaddition of 5wt TiO

2NP caused a 23 increase in Tg and

this improvement reached only 3 when the amount ofTiO2NPwas increased to 15 [9] Also pure PMMA showed

5 weight loss at 217∘C while a higher temperature (310∘C)was needed to create the same effect in the PMMA5wtTiO

2

[9] Recently Totu et al (2018) [14] confirmed the increasein decomposition temperature for PMMATiO

2NP compos-

ite suggesting an improved thermal stability This may beexplained by the reduced intercrystalline distance interac-tion and bond formation betweennanoparticles and polymerchains or the absorption of some energy by the titania par-ticles increasing the thermal stability Final decompositionof the PMMATiO

2NP composite happened at temperatures

620-700∘C with decreasing pattern of the total mass loss asthe amount of nanoparticles increased

The thermal stability of TiO2NP added to PMMA inhibits

the degradation of the resin and improves the thermalstability of the composite material [33] Another explanationfor thermal stability is the migration of TiO

2NP with low

surface energy to the surface of the PMMA resin to forma heat resistant layer [9] The decrease in thermal stabilitywith higher amount of nanofiller may be attributed to theagglomeration of filler particles rather than forming a filler-to-matrix interaction This agglomeration reduces the effectof heat retardation associated with TiO

2NP [33] TiO

2NP

crystalline phase has free electrons that can be associatedwithsurface reactions Oxygen that diffused in the nanocompositesamples was absorbed on the surface of TiO

2NP Hence

diffused oxygen amount in the PMMAmatrix was lower thanin pure PMMA which led to the slower thermooxidativedegradation of the PMMAmatrix [9 33]

It is knows that PMMA shrinks upon polymerizationcausing dimensional changes in the final product Dimen-sional stability is also affected by coefficient of thermalexpansion The result of a study by Hashem et al (2017)[22]showed that pure PMMA and PMMA3TiO

2started to

disintegrate and lose weight at 200∘C with 90 weightloss happening at 400∘C for both materials suggesting nosignificant effect of TiO

2NPon themelting temperature of the

composite material This might be explained by the minimalamount of filler addition or the presence of large number ofdecomposition sites within the material [22]

147 Viscoelastic Behavior Little work has been doneon the effects of TiO

2NP on the viscoelastic behavior

(creep-recovery and relaxation) behavior of PMMA matrixRecently in a study by Alrahlah done to investigate vis-coelastic properties of TiO

2NP-modified PMMA denture

base composite it was found that the creep-recovery andrelaxation behaviors of PMMA were significantly improveddue to the addition of TiO

2NPAlso the improvement further

increased as the concentration of the nanofiller changed from1 to 3This improvement in the behavior indicates the roleof the nanoparticles in increasing the stiffness of the PMMAmatrix owing to the reduction in its molecular mobility andfree volume [43]

148 Electrical Behavior It is imperative to avoid prolongedcontact between oral mucosa and materials with high elec-trical conductivity Metallic particles present in restorativematerials my produce a galvanic effect in the highly con-ductive oral environment causing oral discomfort changesin cell proliferation and immune markers [27 54] Totu andcolleagues (2018) [55] studied the effect of adding differentpercentages of TiO

2NP (0 (control) 02 04 06

10 20 25 and 5) to PMMA used for 3D printingon the electrical properties of the resulting nanocompositeThey reported a decrease in material resistance with theadditions of ge1 TiO

2NP Also an increase in electrical con-

ductivity was noted with the addition of 5 TiO2NP How-

ever the composite material still maintained its insulatingproperty

International Journal of Biomaterials 7

2 Overall Performanceand Clinical Significance

It is well understood that advancements in biomaterialscience affect the progression of technologies in any fieldincluding dental prostheses The introduction of nanomate-rials had significantly changed the clinical and technolog-ical aspects of dentistry In this paper the latest researchprogress on the applications of TiO

2NP in prosthodontics

was reviewed It clearly shows varying responses of phys-ical and mechanical properties of the modified materialswhere a number of properties improved others deterio-rated and few did not change Their level of effectivenessas shown in the literature is diverse being more or lesseffective than pure materials Therefore to attain removableprostheses with improved properties and acceptable clinicalperformance the material of manufacture (acrylic resin)can be enhanced by adding proper percentage of nanofillerinitial surface treatment of the nanoparticles and appro-priate selection of addition method Authors hope that thisreview article would provide some valuable elicitation forfuture scientific and technological innovations in the relatedfield

Based on this review TiO2NPwere found to be enhancers

in some aspects modifiers in some and insignificant in oth-ers The effect depends mainly on NP size addition methodsurface treatment and loading percentage Although the sizeof NP ranged between 5 nm and 350 nm the results of thestudies were not justified based on the nanofiller size anda clear link between size and effect was not established Forthat further investigations to relate the resulting propertiesto nanoparticle size are required

Variations in the results were mainly related to fillermode of addition The addition of nanoparticles to acrylicmonomer was considered more effective owing to betterdispersion of NP within the monomer In this method thedominant improvement was noticed in mechanical prop-erties while physical properties were slightly affected It isworth noting that with this technique the polymer monomerratio may be affected Therefore mixing the nanofillerwith acrylic powder has been suggested and studied Tillnow no study can be found that compares between theeffects of different modes of addition (nanofillers additionto powder or monomer) Based on this review furtherinvestigations of the above-mentioned point are necessaryas well as the proper way to establish the proportion ofpolymermonomer ratio for each method hence nanofilleraddition interferes with the manufacturersquos recommendedratios

The percentage of addition also plays a role in resultingproperties While the range of addition was very broad(05ndash30wt) low percentages resulted in improved prop-erties compared to higher percentages Simple addition of1ndash2wt ratios exhibited improved properties while increas-ing the filler content more than 5wt significantly weakenedthe final nanocomposites In fact the bonding betweenTiO2NP and resin matrix is a critical factor to achieve the

desired properties of nanocomposite As showed in Table 1the treatment of NPwith saline coupling agents improved the

properties in comparison to untreated particles ThereforeNP surface treatment is recommended

According to Table 1 inconsistencies in prepared spec-imen sizes for the same test were seen which may havecontributed to variations in the results between studiesexperimenting with the same filler percentage This reflectsa major error in the methodologies of the studies where thetest should have been done according to standardized spec-imensrsquo dimensions and testing procedures Testing shouldfollow an internationally accepted standardization proto-col like the ADA specifications for denture base polymersto make it possible to compare results between differentstudies

Titanium nanoparticles remain under focus because ofthe antimicrobial efficacy against candida species despitetheir negative effect on a number of properties Incorporationof TiO

2NP into PMMA matrix proved to have antimicrobial

effects specifically on candida species [24] Not to be lost inthis discussion is the effect of TiO

2NP surface modification

on antimicrobial properties of the final product It was shownthat modification with noble metals such as (Ag Au Ptand Pd) on TiO

2NP surface enhanced the photocatalytic

ability of the nanoparticles and bactericidal activity thereafter[12]

Even with this number of studies on recently introducedTiO2NP into PMMA no clear evidence on the clinical

applicability of this nanocomposite has been demonstratedFurther investigations are required to interpret and confirmthe chemical structure changes in PMMATiO

2nanocom-

posite and also to determine the need from otherwise forsurface treatment as well as the proper percentage of additionthat will not affect the final product adversely

Research to improve upon existing nanomaterials is stillongoing with emphasis on efficiency Although the sciencebehind nanotechnology is intriguing the lack of long-termevidence addressing their clinical performance restricts theirwide clinical use Overall there is an essential requirement toinvestigate the durability of these PMMATiO

2composites in

different environmental conditions to extend the applicabilityof these hybrid materials

3 Conclusion

Based on the current review we could conclude thatthe addition of TiO

2NP to PMMA denture bases is still

questionable for working as a reinforcing material andrequires further investigations following the ADA specifica-tions These investigations must explore the chemical andstructural changes happening in the nanocomposite afterTiO2addition The improvements in properties mentioned

above were dominantly seen with lower concentrations ofTiO2and the increase in the amount of added nanopar-

ticles caused adverse effects on resulting PMMATiO2

compositeIn conclusion there is an essential need to investigate the

clinical performance and durability of these nanocompositesin different conditions simulating the oral environment toverify their applicability and provide an insight of possiblefuture researches in this field

8 International Journal of Biomaterials

Table1TiO2NPapplications

indentureb

asea

ndits

effecto

nthetestedprop

ertie

s

Authorsyear

Particlesiz

eAd

ditio

npercentage

Type

ofAc

rylic

Nanocom

positep

reparatio

nProp

ertie

stested

Specim

ensiz

eEff

ects

(IncreaseD

ecreaseUnchanged)

Chatterje

e2010

[9]

5nm

0-15w

tPM

MAfro

mScientificP

olym

erProd

ucts(O

ntario

NY)

(i)MeasuredTiO2NPmixed

with

PMMAfor5

-10min

(ii)D

ACAtwin-screw

extractio

nprocessa

t190∘C

and100rpm

(iii)Ac

rylic

mixed

for6

-7min

andextrud

ed5tim

es

(i)Tensile

mod

ulus

(ii)D

imensio

nal

stability

(iii)Glasstransition

temperature(T

g)

(iv)U

Vabsorptio

n

10x6x03m

m

5mg

(i)Im

provem

entintensile

mod

ulus

(ii)Increased

thermalsta

bility

(iii)IncreasedT g

(iv)Improvem

entinUV

absorptio

n997888rarr

maxim

umat2

TiO2NP

Chatterje

e2010

[10]

5nm

0 20

50 75

100

150

300

PMMAfro

mScientificP

olym

erProd

ucts(O

ntario

NY)

(i)MeasuredTiO2NPmixed

with

PMMAfor5

-10min

(ii)D

ACAtwin-screw

extractio

nprocessa

t190∘C

and100rpm

(iii)Ac

rylic

mixed

for6

-7min

andextrud

ed5tim

es

(i)Glasstransition

temperature(T

g)

(ii)Th

ermalsta

bility

(iii)Decom

position

temperature

10x6x03m

m

(i)T g

increasedlin

early

upto

75TiO2NP

(ii)Th

ermalsta

bilityincreased

(2-15

TiO2NP)

(iii)Decom

position

temperaturesincreased

with

filler

contentu

pto

10TiO2NP

Aneho

suretal

2012

[11]

31nm

ldquoAnataseph

aserdquo

30

Inadditio

nto

surfa

cecoating

DPI

heatcure

acrylic

resin

(In

dia)

(i)Visib

lelig

htactiv

ated

TiO2NPwe

remixed

with

methylm

ethacrylate

mon

omer

(i)Microbial

inhibitory

effect

againstSA

ureus

5x5x2mm

(i)3w

of

TiO2show

santim

icrobialactiv

ityagainstS

Au

reus

Sodagare

tal2013

[12]

21nm

ldquoAnatase

phaserdquo

0 05 10

SelectaP

lus

(self-c

urea

crylic

resin

)

(i)TiO2NPwe

readdedto

acrylic

mon

omer

(i)Flexuralstr

ength

50x10

x33m

m(i)

Flexuralstr

engthdecreasedas

thefi

llerc

ontent

increased

(i)Flexuralmod

ulus

(i)Nochange

inflexu

ral

mod

ulus

Ham

ouda

and

Beyari

2014

[13]

21nm

50

Con

ventionalh

eat

cure

acrylic

resin

(AcrostonWHN

England)

andhigh

impact(M

etrocryl

HiMetrodent

LTDE

ngland

)

(i)TiO2NPwe

remixed

thorou

ghlywith

acrylic

powd

erby

hand

(ii)F

lexu

ral

strength

(iii)To

ughn

ess

65x10

x25mm

(ii)F

lexu

ralstre

ngth

and

toug

hnessd

ecreased

(iv)M

onom

errelease

(iii)Nodifferenceb

etwe

encontroland

TiO2reinforced

regardingmon

omer

release

International Journal of Biomaterials 9

Table1Con

tinued

Authorsyear

Particlesiz

eAd

ditio

npercentage

Type

ofAc

rylic

Nanocom

positep

reparatio

nProp

ertie

stested

Specim

ensiz

eEff

ects

(IncreaseD

ecreaseUnchanged)

Nazirk

aretal

2014

[14]

7nm

ldquoAnatase

phaserdquo

0 05 10

DPI

heatcure

acrylic

resin

(i)TiO2NPaddedto

acrylic

mon

omer

(i)Flexuralstr

ength

65x10

x33mm

(i)Flexuralstr

engthdecreasedas

theT

iO2am

ount

increased

Shirk

avandand

Moslehifard2014

[15]

lt25

nm(averagesim204

nm)

ldquoAnataseand

Rutilep

hasesrdquo

0 05 10

20

Heatcurea

crylic

resin

from

Ivoclar

Vivadent

(i)TiO2NPwe

remixed

with

thea

crylicresin

polymer

inan

amalgamator

for2

0min

(i)Tensile

strength

60x12

x4mm

(i)Tensile

strengthandelastic

mod

ulus

improved

with

1TiO2NP

(ii)0

5and2

TiO2we

reno

tsig

nificantly

different

from

each

othero

rcon

trol

Harinietal2014

[16]

0 10

20

50

Clearh

eatcure

acrylic

resin

(i)Nanop

artic

lesw

ere

incorporated

into

mon

omer

byultrason

icdispersio

n(i)

Flexuralstr

ength

65x10

x3mm

(i)Flexuralstr

engthim

proved

with

TiO2additio

nsig

nificant

differencen

oticed

with

5

Safi2014

[17]

50

Heatcured

enture

base

acrylic

(Sup

eracrylplus

Czecho

slovakia)

(i)Nanop

artic

lesa

dded

tomon

omer

andsonically

dispersed

(i)Coefficientof

thermalexpansion

(ii)M

odulus

(iii)Glasstransition

15x6mm

Cylin

ders

65x10

x25mm

Powd

erform

(10g)

(i)Decreaseincoeffi

cientof

thermalexpansion

(ii)D

ecreased

inmod

ulus

ofelastic

ity

(iii)IncreasedT g

Alwanand

Alameer2015

[18]

lt50

nmsiz

e0 30

(i)Silanizedwith

TMSP

M

Heatcurea

crylic

resin

(i)SilanizedTiO2NPwe

readdedto

mon

omer

and

sonicated

(i)Im

pactstr

ength

(ii)T

ransverse

strength

(iii)Hardn

ess

(iv)S

urface

roug

hness

(v)W

atersorptio

nandsolubility

80x10

x4mm

65x10x25m

m

50x05m

mdisc

(i)Increased

(ii)Increased

(iii)Increased

(iv)Increased

(v)D

ecreased

10 International Journal of Biomaterials

Table1Con

tinued

Authorsyear

Particlesiz

eAd

ditio

npercentage

Type

ofAc

rylic

Nanocom

positep

reparatio

nProp

ertie

stested

Specim

ensiz

eEff

ects

(IncreaseD

ecreaseUnchanged)

Ahm

edetal2016

[19]

46nm

0 10

50

Con

ventionalh

eat

cure

acrylic

resin

(ImplacrylVe

rtex)

andhigh

impact

heatcureacrylic

resin

(Vertex-Dental

Netherla

nds)

(i)TiO2NPwe

readdedinto

acrylic

resin

(i)Flexuralstr

ength

(ii)Impactstr

ength

(iii)Hardn

ess

50x10

x3mm

60x6x4mm

25x10

x3mm

(i)Decreased

with

TiO2

additio

n

(ii)Increased

onlyfor

conventio

nalacrylicresin

mod

ified

by1

(iii)Increasedwith

5additio

nTiO2NPforb

othtypeso

facrylic

Sodagare

tal2016

[20]

21nm

05 10

SelectaP

lus

(self-c

urea

crylic

resin

)

(i)Nanop

artic

lesw

erea

dded

toacrylic

mon

omer

and

stirred

(i)Antim

icrobial

prop

ertie

s20

x20

x1m

m

(i)TiO2redu

cedmicrobial

grow

thatbo

thconcentrations

at90

min

underU

VAexpo

sure

(ii)A

ntim

icrobialactiv

ityof

TiO2istim

edependent

Ahm

edetal2017

[21]

lt25

nm0 05 10

Heatcurea

crylic

resin

from

Dentsp

lyInternationalInc

(ChicagoIL

USA

)

(i)TiO2NPwe

readdedto

acrylic

polymer

andmixed

usingam

algam

capsule

(i)Flexuralstr

ength

(ii)F

racture

toug

hness

(iii)Hardn

ess

65x10

x25mm

65x10

x25mm

30x10

x25mm

(i)Increasedwith

both

filler

percentages

(ii)N

oeffecto

nfracture

toug

hnesso

fbothfiller

percentages

(iii)Increasedwith

1filler

Hashem

etal2

017

[22]

90nm

0 10

20 30

Self-cureacrylic

resin

from

Eco-crylcold

Protechn

o(Spain)

(i)TiO2NPwe

remixed

with

them

onom

er

(i)Flexuralmod

ulus

andflexu

ral

strength

(ii)H

ardn

ess

(iii)Surfa

cewe

tting

30x8x1m

m

50x1m

mdiscs

(i)Increasedlin

early

(ii)Increased

(iii)Re

ducedwith

1filler

contentand

increasedwith

high

erpercentages

(iv)T

gdecreasedwith

TiO2

additio

n

Ghahrem

anietal

2017

[23]

20-30nm

ldquoAnatase

phaserdquo

0 10

SRTriplexHot

heatcureacrylic

resin

(Ivoclar

Vivadent

Inc

Schaan

Liechtenste

in)

(i)TiO2NPwe

remixed

with

acrylic

resin

powd

erin

anultrason

icmixer

(i)Tensile

strength

(ii)Impactstr

ength

60x12

x39mm

75x10

x10

mm

(i)Increased

(ii)Increased

International Journal of Biomaterials 11Ta

ble1Con

tinued

Authorsyear

Particlesiz

eAd

ditio

npercentage

Type

ofAc

rylic

Nanocom

positep

reparatio

nProp

ertie

stested

Specim

ensiz

eEff

ects

(IncreaseD

ecreaseUnchanged)

Totu

etal2017

[24]

65-170

nm

0 02

04 1 25

PMMA+P

EMAfor

3Dprintin

g(eDent

100En

visio

nTec

GmbH

Gladb

eck

Germany)

(i)Nanop

artic

lesw

erea

dded

into

PMMAsolutio

nwith

continuo

usstirringand

ultrason

icmixingfor1

hour

(i)Antim

icrobial

effect(Ca

ndida

scotti)

(ii)C

omplete

denture

manufacturin

gusin

gste

reolith

ograph

y

(i)041

and25

inhibited

cand

idagrow

th

(ii)P

MMA04TiO2compo

site

successfu

llyused

ford

enture

fabrication

Aziz2018

[25]

30nm

0 30

Highim

pactheat

cure

acrylic

resin

(Vertex-Dental

Netherla

nds)-

(i)TiO2NPwe

redispersedin

mon

omer

andsonicatedat

120W

and60

KHzfor

3minutes

(i)Im

pactstr

ength

(ii)C

olor

stability

(iii)Th

ermal

cond

uctiv

ity

80x10

x4mm

35x15

x05mm

40x25mm

(i)Increased

(ii)Increased

colorstabilityfor

testgrou

ps

(iii)Noeffect

Alra

hlah

etal

2018

[26]

80-100

nm

0 1 2 3

Heatcurea

crylic

resin

(Lucito

ne550Dentsp

lyInt

IncPaU

SA)

(i)Hardn

essa

ndmod

ulus

(ii)T

gdegradation

temperatureand

rate

(iii)Cr

eep-recovery

andrelaxatio

nbehavior

(iv)A

ntibacteria

ladhesio

n

50x10

mm

discs

cutindifferent

sizes

ford

ifferent

tests

7mg

5x10

mm

(i)Increased

(ii)S

light

increase

with

2nano

-fillerc

ontent

(iii)Im

provem

entinbehavior

(iv)D

ecreaseinbacterial

attachmentcon

tent

Karcietal2018

[27]

13nm

0 1 3 5

(i)Au

to-polyeriz

ed(H

eraeus

Kulze

rNew

bury

Berkshire

UK)

(ii)

Heat-p

olym

erized

Heraeus

Kulze

rNew

bury

Berkshire

UK

(iii)Microwave-

polymerized

(GC

DentalTo

kyo

Japan)

(i)TiO2NPwe

remixed

with

acrylic

resin

powd

erusing

ballmillingat40

0rpm

for2

hours

(i)Flexuralstr

ength

65x10

x3mm

(i)Increasedforh

eat-and

auto-polym

erized

acrylic

at1

(ii)D

ecreased

fora

lltypeso

facrylic

at5

12 International Journal of Biomaterials

Table1Con

tinued

Authorsyear

Particlesiz

eAd

ditio

npercentage

Type

ofAc

rylic

Nanocom

positep

reparatio

nProp

ertie

stested

Specim

ensiz

eEff

ects

(IncreaseD

ecreaseUnchanged)

Totu

etalTo

tuet

al2

017[28]

ldquoAnatase

phaserdquo

0 02

04

06 10

25

(i)PM

MA-

MA

(ii)P

MMA-

MMA-

BPO

(iii)3D

printed

PMMA(eD

Envisio

nTec

GmbH

Gladb

eck

Germany)

(i)TiO2mod

ified

bymethacrylicacid

then

manually

mixed

with

PMMAmixture

(i)Th

ermalsta

bility

(ii)T

g

Stereolitho

graphic

dentures

(i)Increased(im

proved)

(ii)Increased

Totu

etal2018

[29]

ldquoAnatase

phaserdquo

0 02

04

06 10

20 25 50

PMMAfor3

Dprintin

g(eDent

100En

visio

nTec

GmbH

Gladb

eck

Germany)

(i)Re

sistance

(ii)E

lectric

alcond

uctiv

ity

(iii)Dielectric

constant

(i)Decreased

with

1020

25

and5

(ii)Increased

butm

aterialstill

maintainedinsulatin

gprop

ertie

s

(iii)Increasedwith

5

International Journal of Biomaterials 13

Conflicts of Interest

The authors declare that they have no conflicts of interest

References

[1] R L Sakaguchi and J M Powers Craigrsquos Restorative DentalMaterials Elsevier Health Sciences Philadelphia PA USA pp163-176 2012

[2] N Murakami N Wakabayashi R Matsushima A Kishidaand Y Igarashi ldquoEffect of high-pressure polymerization onmechanical properties of PMMA denture base resinrdquo Journalof the Mechanical Behavior of Biomedical Materials vol 20 pp98ndash104 2013

[3] R Adhikari and G H Michler ldquoPolymer nanocompositescharacterization by microscopyrdquo Polymer Reviews vol 49 no3 pp 141ndash180 2009

[4] A Navidfar T Azdast and A Karimzad Ghavidel ldquoInfluenceof processing condition and carbon nanotube on mechani-cal properties of injection molded multi-walled carbon nan-otubepoly(methyl methacrylate) nanocompositesrdquo Journal ofApplied Polymer Science vol 133 no 31 Article ID 43738 pp1ndash9 2016

[5] P Chaijareenont H Takahashi N Nishiyama and M Ark-sornnukit ldquoEffect of different amounts of 3-methacryloxypro-pyltrimethoxysilane on the flexural properties and wear resis-tance of alumina reinforced PMMArdquo Dental Materials vol 31no 4 pp 623ndash628 2012

[6] J Jordan K I Jacob R TannenbaumMA Sharaf and I JasiukldquoExperimental trends in polymer nanocompositesmdasha reviewrdquoMaterials Science and Engineering A vol 393 no 1-2 pp 1ndash112005

[7] MMGad SM Fouda F A Al-Harbi RNapankangas andARaustia ldquoPMMAdenture base material enhancement A reviewof fiber filler and nanofiller additionrdquo International Journal ofNanomedicine vol 12 pp 3801ndash3812 2017

[8] F Li S Zhou B You and L Wu ldquoKinetic study onthe UV-induced photopolymerization of epoxy acrylateTiO2nanocomposites by FTIR spectroscopyrdquo Journal of AppliedPolymer Science vol 99 no 6 pp 3281ndash3287 2006

[9] A Chatterjee ldquoProperties improvement of PMMA using nanoTiO2rdquo Journal of Applied Polymer Science vol 118 no 5 pp2890ndash2897 2010

[10] P Harini K Mohamed and T V Padmanabhan ldquoEffect ofTitanium dioxide nanoparticles on the flexural strength ofpolymethylmethacrylate An in vitro studyrdquo Indian Journal ofDental Research vol 25 no 4 pp 459ndash463 2014

[11] G Venkatesh Anehosur R D Kulkarni M G Naik et alldquoSynthesis and Determination of Antimicrobial Activity ofVisible Light Activated TiO2 Nanoparticles with PolymethylMethacrylate Denture Base Resin Against StaphylococcusAureusrdquo Journal of Gerontology ampGeriatric Research vol 01 no01 pp 103ndash111 2012

[12] A Sodagar A Bahador S Khalil A Saffar Shahroudi and MZaman Kassaee ldquoThe effect of TiO

2and SiO

2nanoparticles on

flexural strength of poly (methyl methacrylate) acrylic resinsrdquoJournal of Prosthodontic Research vol 57 no 1 pp 15ndash19 2013

[13] I M Hamouda and M M Beyari ldquoAddition of glass fibers andtitanium dioxide nanoparticles to the acrylic resin denture basematerial comparative study with the conventional and highimpact typesrdquo Oral Health and Dental Management vol 13 pp107ndash112 2014

[14] E E Totu C M Cristache E Voicila et al ldquoOn physicaland chemical characteristics of Poly(methylmethacrylate) na-nocomposites for dental applications IrdquoMateriale Plastice vol54 no 4 pp 666ndash672 2017

[15] S Shirkavand and EMoslehifard ldquoEffect of TiO2 nanoparticleson tensile strength of dental acrylic resinsrdquo Journal of DentalResearch Dental Clinics Dental Prospects vol 8 no 4 pp 197ndash203 2014

[16] M Karci N Demir and S Yazman ldquoEvaluation of FlexuralStrength of Different Denture Base Materials Reinforced withDifferent Nanoparticlesrdquo Journal of Prosthodontics 2018

[17] O Gurbuz F Unalan and I Dikbas ldquoComparison of thetransverse strength of six acrylic denture resinsrdquo OhdmbscMagazines vol 9 pp 21ndash24 2010

[18] S A Alwan and S S Alameer ldquoThe Effect of the Addition ofSilanized Nano Titania Fillers on Some Physical and Mechan-ical Properties of Heat Cured Acrylic Denture Base MaterialsrdquoJournal of Baghdad College of Dentistry vol 27 no 1 pp 86ndash912015

[19] M Ashour Ahmed M El-Shennawy Y M Althomali andA A Omar ldquoEffect of Titanium Dioxide Nano Particles In-corporation on Mechanical and Physical Properties on TwoDifferent Types of Acrylic Resin Denture Baserdquo World Journalof Nanoscience and Engineering vol 06 no 03 pp 111ndash119 2016

[20] A Sodagar S Khalil M Z Kassaee A S Shahroudi B Pourak-bari and A Bahador ldquoAntimicrobial properties of poly (methylmethacrylate) acrylic resins incorporated with silicon dioxideand titanium dioxide nanoparticles on cariogenic bacteriardquoJournal of Orthodontic Science vol 5 no 1 pp 7ndash13 2016

[21] M A Ahmed A A Omar M El-Shennawy M I Ebrahimand Y M Althomali ldquoInfluence of addition of different types ofnano-fillers on the microstructure and mechanical propertiesof PMMA based denture resinrdquo Kasmera Journal vol 45 pp48ndash59 2017

[22] MHashemM F Al Rez H Fouad et al ldquoInfluence of titaniumoxide nanoparticles on the physical and thermomechanicalbehavior of poly methyl methacrylate (pmma) A denture baseresinrdquo Science of Advanced Materials vol 9 no 6 pp 938ndash9442017

[23] L Ghahremani S Shirkavand F Akbari and N SabzikarildquoTensile strength and impact strength of color modified acrylicresin reinforcedwith titaniumdioxide nanoparticlesrdquo Journal ofClinical and Experimental Dentistry vol 9 no 5 pp e661ndashe6652017

[24] E E Totu A C Nechifor G Nechifor H Y Aboul-Eneinand C M Cristache ldquoPoly(methyl methacrylate) with TiO2nanoparticles inclusion for stereolitographic complete denturemanufacturing minus the fututre in dental care for elderly edentu-lous patientsrdquo Journal of Dentistry vol 59 pp 68ndash77 2017

[25] H K Aziz ldquoTiO-Nanofillers Effects on Some Properties ofHighly- Impact Resin Using Different Processing TechniquesrdquoThe Open Dentistry Journal vol 12 no 1 pp 202ndash212 2018

[26] M Tsuji T Ueda K Sawaki M Kawaguchi and K SakuraildquoBiocompatibility of a titanium dioxide-coating method fordenture base acrylic resinrdquo Gerodontology vol 33 no 4 pp539ndash544 2016

[27] S PodzimekM Tomka P Sommerova Y Lyuya-Mi J Bartovaand J Prochazkova ldquoImmune markers in oral discomfortpatients before and after elimination of oral galvanismrdquo Neu-roendocrinology Letters vol 34 no 8 pp 802ndash808 2013

[28] S Kiat-amnuayM Beerbower JM Powers andRD ParavinaldquoInfluence of pigments and opacifiers on color stability of

14 International Journal of Biomaterials

siliconemaxillofacial elastomerrdquo Journal ofDentistry vol 37 no1 pp e45ndashe50 2009

[29] S H Tuna F Keyf H O Gumus and C Uzun ldquoThe evaluationof water sorptionsolubility of various acrylic resinsrdquo EuropeanJournal of Dental Education vol 2 pp 191ndash197 2008

[30] S M Khaled R Sui P A Charpentier and A S RizkallaldquoSynthesis of TiO

2-PMMA nanocomposite using methacrylic

acid as a coupling agentrdquo Langmuir vol 23 no 7 pp 3988ndash39952007

[31] L Reijnders ldquoThe release of TiO2 and SiO2 nanoparticles fromnanocompositesrdquo Polymer Degradation and Stability vol 94no 5 pp 873ndash876 2009

[32] G Nazirkar S Bhanushali S Singh B Pattanaik and N RajldquoEffect of Anatase Titanium Dioxide Nanoparticles on theFlexural Strength of Heat Cured Poly Methyl MethacrylateResins An In-Vitro Studyrdquo Journal of Indian ProsthodontistSociety vol 14 pp 144ndash149 2014

[33] A Chatterjee ldquoEffect of nanoTiO2addition on poly(methyl

methacrylate) an exciting nanocompositerdquo Journal of AppliedPolymer Science vol 116 no 6 pp 3396ndash3407 2010

[34] S Rashahmadi R Hasanzadeh and S Mosalman ldquoImprov-ing the Mechanical Properties of Poly Methyl MethacrylateNanocomposites for Dentistry Applications Reinforced withDifferent Nanoparticlesrdquo PolymermdashPlastics Technology andEngineering vol 56 no 16 pp 1730ndash1740 2017

[35] A H Yuwono B Liu J Xue et al ldquoControlling the crystallinityand nonlinear optical properties of transparent TiO

2-PMMA

nanohybridsrdquo Journal of Materials Chemistry vol 14 no 20 pp2978ndash2987 2004

[36] J K Pandey K RaghunathaReddy A P Kumar andR P SinghldquoAn overviewon the degradability of polymer nanocompositesrdquoPolymer Degradation and Stability vol 88 no 2 pp 234ndash2502005

[37] C Tao S Jianping J Weng L Ting and H Xiaozhu ldquoPrepara-tion and properties of PMMATiO2 nanocompositerdquoChemicalReaction Engineering andTechnology vol 23 pp 435ndash440 2007

[38] A H Yuwono J Xue J Wang et al ldquoTransparent nanohybridsof nanocrystalline TiO2 in PMMA with unique nonlinearoptical behaviorrdquo Journal of Materials Chemistry vol 13 no 6pp 1475ndash1479 2003

[39] R Alla K N Raghavendra R Vyas and A KonakanchildquoConventional and contemporary polymers for the fabricationof denture prosthesis Part I overview composition and proper-tiesrdquo International Journal of Applied Dental Sciences vol 1 noPart I pp 82ndash89 2015

[40] C C Trapalis P Keivanidis G Kordas et al ldquoTiO2(Fe3+)nanostructured thin films with antibacterial propertiesrdquo ThinSolid Films vol 433 no 1-2 pp 186ndash190 2003

[41] L S Acosta-Torres L M Lopez-Marın R E Nunez-Anita GHernandez-Padron and V M Castano ldquoBiocompatible Metal-Oxide Nanoparticles Nanotechnology Improvement of Con-ventional Prosthetic Acrylic Resinsrdquo Journal of Nanomaterialsvol 2011 Article ID 941561 8 pages 2011

[42] A Bahador S Khalil B Pourakbari et al ldquoPhotocatalyticEffects of Acrylic Resins Incorporated with Nano-titaniumDioxide on Planktonic and Biofilm Growth of Four CariogenicBacteriardquo Annual Research amp Review in Biology vol 4 no 17pp 2695ndash2708 2014

[43] A Alrahlah H Fouad M Hashem A Niazy and A AlBadahldquoTitanium Oxide (TiO2)Polymethylmethacrylate (PMMA)Denture Base Nanocomposites Mechanical Viscoelastic and

Antibacterial BehaviorrdquoMaterials vol 11 no 7 Article ID 1096pp 10961ndash109615 2018

[44] A Kubacka M Ferrer M L Cerrada et al ldquoBoostingTiO2-anatase antimicrobial activity Polymer-oxide thin filmsrdquoApplied Catalysis B Environmental vol 89 no 3-4 pp 441ndash4472009

[45] Y Cheng T Sakai R Moroi et al ldquoSelf-cleaning abilityof a photocatalyst-containing denture base materialrdquo DentalMaterials vol 27 no 2 pp 179ndash186 2008

[46] C M Bollen P Lambrechts and M Quirynen ldquoComparisonof surface roughness of oral hard materials to the thresholdsurface roughness for bacterial plaque retention a review of theliteraturerdquoDental Materials vol 13 no 4 pp 258ndash269 1997

[47] N Elshereksi M Ghazali A Muchtar and C Azhari ldquoEffectof nanobarium titanate addition on the surface characteristicsof denture base resinrdquo International Journal of Mechanical andProduction Engineering vol 5 pp 1ndash8 2017

[48] Y Xia Z Feimin H Xie and N Gu ldquoNanoparticles reinforcedresin based dental compositesrdquo Journal of Dentistry vol 36 pp450ndash455 2008

[49] S Mosalman S Rashahmadi and R Hasanzadeh ldquoThe effectof TiO2 nanoparticles on mechanical properties of poly methylmethacrylate nanocompositesrdquo International Journal of Engi-neering Transactions B Applications vol 30 no 5 pp 807ndash8132017

[50] Y Han S Kiat-amnuay J M Powers and Y Zhao ldquoEffectof nano-oxide concentration on the mechanical properties ofa maxillofacial silicone elastomerrdquo The Journal of ProstheticDentistry vol 100 no 6 pp 465ndash473 2008

[51] I N Safi ldquoEvaluation the effect of nanomdashfillers (TiO2 AL2O3

SiO2) addition on glass transition temperature E-moudulus

and coefficient of thermal expansion of acrylic denture basematerialrdquo Journal of Baghdad College of Dentistry vol 26 no1 pp 37ndash41 2014

[52] W Wang S Liao Y Zhu M Liu Q Zhao and Y Fu ldquoRecentApplications of Nanomaterials in Prosthodonticsrdquo Journal ofNanomaterials vol 2015 Article ID 408643 11 pages 2015

[53] L Sun R F Gibson F Gordaninejad and J Suhr ldquoEnergyabsorption capability of nanocomposites A reviewrdquoCompositesScience and Technology vol 69 no 14 pp 2392ndash2409 2009

[54] S Podzimek K Hana M Miksovsky et al ldquoThe Influence ofgalvanic currents and voltage on the proliferation activity oflymphocytes and expression of cell surface moleculesrdquo FoliaBiologica vol 54 no 5 pp 146ndash150 2008

[55] E E Totu E Voicila V Pistritu G Nechifor and C MCristache ldquoEvaluation of electrical characteristics for PMMA-TiO2 nanocomposites used in dentistryrdquo Evista de Chimie vol69 no 1 pp 155ndash159 2018

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Journal ofNanomaterials

Submit your manuscripts atwwwhindawicom

International Journal of Biomaterials 3

Search on PubMed - Google scholar - Scopus

bull 48 Articles found

27 Articles were excluded

bull 6 articles - studied the effect of surface coatingbull 3 articles - used micro-sized titania particlesbull 3 articles - studied barium titanatebull 3 articles - did not use PMMA not for denture basesbull 3 articles - were reviewsbull 2 articles - studied a mixture of nano-fillersbull PMMAreinforcedmicaandABW2ZrOstudied-articles2

as base materialbull 2 articles - lacked full databull 1 article - studied nano-tubesbull 1 article - studied gallate modified particlesbull 1 article - was in Chinese language

21 Articles were included

bull Used PMMA for denture basesbull nano-sizethein2TiOUsedbull Studied physical mechanical chemical anti-microbial

electrical or thermal propertiesbull Written in English

Figure 1 Study design

of PMMA polymer in two different ways One way is theformation of H-bond between carbonyl group (-C=O) andsurface hydroxyl group (-OH) of TiO

2NP The other way is

the binding of TiO2NP with two oxygen atoms of -COOR by

a bidentate coordination to Ti4+ cation [9] When TiO2NP

come to the surface they form crosslinks with PMMA [9] Asthe amount of TiO

2NP loading within the PMMA increases

this bonding also increases All this is possible because ofthe hydroxyl group on the surface of TiO

2NP and the -

C=O (Carbonyl) -OH (Hydroxyl) -COOH (Carboxyl) and-COOR (Ester) groups in the polymer matrix The crosslinking has been confirmed by Fourier-transform infraredspectroscopy (FTIR) [22 33]

The dispersion of the TiO2NP within the matrix hin-

ders polymer chain movements due to the strong adhesionbetween the TiO

2NP and PMMA As a result better modulus

is seen with TiO2NP-PMMA composite materials [9] Other

investigators reported increased stiffness of the compositematerial and decreased PMMAmobility [19]Thismay be dueto the large interface of TiO

2NP when wrapped in PMMA

which possesses a smaller dielectric coefficient There will bea strong electric interaction between them resulting in anelectric dipole layer at the nanoparticle surface In terms of

the atomic bonding the origin of the nonlinear refractiveindex may be due to the hyperpolarizability of Ti-O pairs [2138] Moreover the addition of spherical nanoscale particles iscapable of filling the interpolymeric spaces which was foundto enhance the polishability of the material [15]

14 Properties of PMMA1198791198941198742 Nanocomposite As men-tioned earlier PMMA is the most predominant polymer-based material for dentures However its mechanical andsurface properties are low [39] The addition of any materialto improve the antimicrobial properties of the PMMA shouldnot have an adverse effect on the mechanical propertiesIn reverse it is highly preferred to add a material that willimprove both biological and mechanical properties [34]TiO2NP is commonly used as a coloring agent and filler It

is capable of increasing the toughness of polymers producinga composite material with superior properties [40] With theadded antimicrobial property it is incorporation into PMMAresins is extensively used in oral removable appliances [41]Therefore the properties of the nanocompositewere screenedin this review to evaluate the reliability of TiO

2NP as

an additive to improve the performance of PMMATiO2

nanocomposite denture base material

4 International Journal of Biomaterials

141 Antimicrobial Activities TiO2NP were found to have

an intrinsic antimicrobial property due the production ofcytotoxic oxygen radicles [26] TiO

2NP are ideal additives

because of their nontoxicity and chemical stability Howeverunder certain conditions they have an antimicrobial ability[41] When they are exposed to UV-light in the presenceof oxygen and water they decompose and oxidize othercompounds organic and inorganic Therefore they canbe considered as antimicrobial additive [41] FurthermoreTiO2NP had the ability to inhibit the adherence of cariogenic

bacteria in planktonic phase as well as in later phases ofbiofilm formation The addition of TiO

2NP to PMMA resin

used for dentures or other oral appliances will have a positiveeffect against microbial colonization [42]

Anehosur et al (2012) found that the addition of 3wt TiO

2NP to PMMA produced a positive antimicrobial

effect It had the ability to reduce microbial number whichprevents quorum sensing thereby halts plaque formationon PMMATiO

2nanocomposite surface [11] Due to the

photocatalytic property againstmicroorganisms patients willbe able to maintain the hygiene of their dentures easilyby exposing them to solar energylight sources to activatethe TiO

2NP [11] On the same way Alrahlah et al (2018)

reported a 50 and 90 decrease in bacterial cell attach-ment of E faecalis and P aeruginosa respectively with themere addition of 3 TiO

2NP [43] Likewise Totu et al

(2017) investigated the effect of incorporating TiO2NP into

a 3D-printed PMMA denture in an attempt to improvedenture antimicrobial characteristics and found that even thesmall addition of 04 of TiO

2NP to PMMA resulted in a

nanocomposite that prevented the colonization of microor-ganisms and further formation of biofilm [24] As a resultTiO2NP could be incorporated into denture PMMA resin to

successfully fabricate antimicrobial dentures [24] The largeactive surface area of the nanoparticles compared to theirsmall size makes them highly effective in low percentagesof addition It was found that as low as 04 1 and 25TiO2NP inhibited the growth of Candida As reported in

the literature TiO2NP caused a halt in the cellular enzymes

and increased cell wall permeability causing cell death[44]

Few studies reported that the addition of asmuch as 5wtTiO2NP to the PMMA is needed to achieve the antimicrobial

effect [45] However with this addition structural decompo-sition and material weakening may occur [26]

142 Surface Properties Surface microtopography of thedenture is a very important feature inmicrobial adhesion andplaque formation and subsequently denture stomatitis

(1) Surface Roughness Denture wearers have high prevalenceof poor oral health This is mostly caused by the surfacecontours of the dentures and the irregularities of the oralmucosa [45] Many factors were found to have an effect onthe surface roughness (Ra) of denture bases one of whichis the reinforcing material of the acrylic resin [46] Alwanand Alameer (2015) found an increase in surface roughnesswith the addition of 3wt of TiO

2NP to PMMA denture

base material and attributed this increase to the presence ofnanoparticles on the surface of specimens [18]

To establish a relation between contact angle (wetting)and the amount of TiO

2NPfiller in the PMMAresin Hashem

et al (2017) found that it is dependent on filler amountThe addition of 1wt TiO

2NP led to a reduction in surface

wetting while the addition of more filler improved wettingThis finding confirms the effect of fillers on the surfaceof composite material compared to the pure counterpart[22]

While few investigations weremade on surface roughnessof PMMATiO

2nanocomposite a significant increase was

reported compared to pure PMMA [18] As the surface getsrougher and Ra values increase the surface area increasesmeaning more sites are available for microbial adhesion andcolonization One of the most common organisms to beharbored on the surface of acrylic denture bases isC Albicans[47] Studies have reported that the surface roughness ofa denture should not exceed 02 120583m [45] Although thereis a direct relation between surface roughness and candidaadhesion (increased roughness increases candida adhesion)the reduction in candida count confirms the antifungalproperties of TiO

2NP

(2) Hardness Reports have confirmed that TiO2NP im-

proved the hardness of heat cure PMMA [10 18] Xia etal (2008) attributed the increase in surface hardness totwo factors proper filler content and use of silane-couplingagent which increases the bonding between filler and resinmatrix [48]The effect on surface hardness was detected withadditions of TiO

2NP as low as 1 [21] In another study

investigating the addition of 05 1 and 2 hardnessvalues were found to increase with the addition and thehighest values were seen with 2wt TiO

2 Mosalman et al

(2017) related this to increased number of bonds betweenmatrix and fillers which requires more energy to break thesebonds [49] Hashem et al (2017) reported an increase inhardness values that reached 20 30 and 34 more thanpure PMMA with 1 2 and 3 TiO

2NP respectively This

was explained by the increase in material stiffness due topresence of rigid particles within the matrix in addition toreduction of matrix mobility [22]

Alwan and Alameer (2015) concluded that 3 additionof TiO

2caused a significant increase in surface hardness

compared to pure PMMA [18] while Ahmed et al (2016)suggested the need of adding 5 TiO

2NP to increase surface

hardness of conventional and high impact heat cure acrylicresin to remarkable values [19] More recently Alrahlah et al(2018) confirmed the increase in surface hardness of up to35 with 3 TiO

2NP addition The values of the hardness

measurements were higher at the surface of the compositeresin and decreased as we move inward toward the core ofthe material suggesting higher crosslinking at the surface[43] Regarding selection of the most appropriate concen-tration of filler for inclusion within denture resin results ofmulticriteria decision making (MCDM) method suggestedthat a filler content in the range of 2wt would create acomposite material with improved mechanical propertiesincluding surface hardness [34]

International Journal of Biomaterials 5

143 Mechanical Properties

(1) Flexural Properties During function oral appliancesincluding dentures are exposed to a magnitude of deformingstresses and any factor that increases the deformation of thedenture base may lead to fracture [17] One of the factorsthat may change the amount of denture deformation is theadditive into the PMMA resinThe effect of TiO2NP additionon flexural strength of PMMA is partially dependent onthe type of acrylics and the concentration of nanoparti-cles [19] In 2013 Sodagar et al investigated the effect ofadding 05 and 1 TiO2NP into PMMA and reporteda decrease in flexural strength PMMA containing 05wtshowed the lowest values It was concluded that there isan inverse relation between the concentration of the fillerand the flexural strength of reinforced PMMA [12] Hanet al (2008) reached the same conclusion and related theresults to agglomeration of particles within the matrix whichmakes them stress concentrations areas [50] Other studiesalso reported a reduction in flexural strength [13 19 32]and modulus of elasticity [51] with the addition of TiO

2NP

Hamouda et al (2014) found that TiO2NP caused a reduction

in flexural strength with no change in flexural modulus [13]In the same token Nazirkar et al in (2014) were exploringthe effect of adding TiO

2NP into heat cure acrylic resin on

antimicrobial properties and reported an adverse effect onflexural strength of the final product [32]

In contrast to previous studies superior flexural proper-ties were reported with different concentrations of TiO

2NP

added to PMMA than those of normal PMMA [10 18 21 52]This improvement may be attributed to the effect of silaniza-tion of TiO

2NP [18] or the good dispersion of fillers within

the matrix which improves modulus transverse strengthand ductility [18 52] Hashem et al (2017) found that with05ndash3wt TiO

2NP addition flexural strength and modulus

increased Moreover they suggested that reinforced PMMAcould offer superior chemical and mechanical propertiesmaking it a better option for dentures than pure PMMA resin[22] On the same way Rashahmadi et al (2017) found thatthe mere addition of 05 TiO

2NP improved the flexural

strength and Youngrsquos modulus by 4 Based on MCDMresults TiO

2NP addition to PMMA is an excellent option

for improving properties of PMMA for dental applicationsespecially in 2wt concentration [34] In a recent studyby Karci et al (2018) [16] different types (heat- auto- andmicrowave polymerized) of acrylic mixed with 1 3 and5 nanotio2 were used to test the flexural strength of theresulting composite That study came to a conclusion thatthe addition of 1 TiO

2NP to heat- and autopolymerized

acrylic could improve the flexural strength while it remainedunchanged with 3 TiO

2NP and decreased with 5 for all

types of acrylicThiswas explained by the increase in agglom-eration of nanoparticles at higher addition percentages

In a study by Mosalman et al (2017) various percentagesof TiO

2NP (05 1 and 2wt ) were added to pure PMMA

and found that the flexural strength of all groups stayedunchanged Sampleswith 05wtTiO

2NP showed only 375

improvement in flexural strength compared to pure PMMAYoungrsquos modulus for all groups was improved with the

highest value seen in samples containing 2wt TiO2NP

[49]

(2) Impact Strength With regard to impact strength theaddition of TiO

2NP to heat cured acrylic resin resulted

in a positive effect compared to pure PMMA [18] Studieshave confirmed this finding with different concentrationsof TiO

2NP including 1 [19 23] 2wt[34 49] and 3wt

[25] The same finding was reported after the addition ofsilanized TiO

2NP [53] The detected increase in impact

strength was justified by good bonding between PMMAmatrix and TiO

2nanofillers These fillers reside in small

voids between polymer chains and result in slow segmentalmotion Also they provide large surface area due to theirsmall size which helps in energy dissipation [25] Otherssuggested that the nanofillers in the acrylic resin toleratemost of the applied load while the resin matrix helps instructural integrity and load distribution which eventuallyinhibits crack propagation [23]

(3) Tensile Strength Shirkavand and Moslehifard (2014)investigated the effect of 05wt 1wt and 2wt TiO

2NP

on tensile strength of PMMA base resins and found that thetensile strength of nanocomposite was the highest with 1wtTiO2NP and the improvement was 35 more compared to

pure PMMA However further increase in TiO2NP content

led to an adverse effect [15] due to clustering of TiO2NP

The fillers work as impurities and act as defects and stressconcentration centers [15 49] The same results were alsoreported by Ghaheremani et al (2017) [23] The increase intensile strength is probably attributed to the fact that follow-ing the incorporation of nanoparticles into acrylic powderthe applied load is mainly tolerated by these nanoparticles

Contrary to previous studies Chatterjee in 2010 foundthat nanocomposite with filler content as high as 5wt and15wt had a 59 and 95 increase in tensile modulusrespectively compared to that of pure PMMA [9] This wascaused by the strong adhesion between TiO

2NP and PMMA

The applied load is transferred through these interfacialsurfaces to the strongest material that is the nanoparticles [9]

144 Color Stability It is noteworthy that the reinforcingfiller material should ideally improve the mechanical proper-ties without causing an adverse reaction to the aesthetics [2541] TiO

2NP have whitish color therefore the appropriate

percentage of this additive that fulfills the aforementionedrequirement should be considered An objective evaluation ofthe color change is usually done using a spectrophotometerwhere the difference between light absorption between dif-ferent samples is calculated [28] Aziz in 2018 evaluated thecolor change after adding 3wt of TiO

2NP and found that

the amount of light absorbed increasedmaking the reinforcedspecimens more opaque compared to pure PMMA Thischange was due to the presence of TiO

2NP within the

matrix which absorbs more light than polymer matrix duehigh atomic number [25] Further studies are required todetermine the proper TiO

2NP percentage needed to attain

a PMMATiO2nanocomposite with superior properties and

acceptable aesthetics

6 International Journal of Biomaterials

145 Water Sorption Solubility and Porosity Conventionalacrylic resins have voids and porosities that allow watermolecules exchange which could be the leading cause forwater sorption and solubility [18]The nature of denture resinmaterial allows it to absorb water which acts as a plasticizerand affects the material dimensional stability and denturedurability [41]Thewatermolecules force themselves betweenpolymer chains move them apart create internal stressesand result in crack formation [29] As reported by Alwan andAlameer [18] the addition of TiO

2NP to heat cure acrylic

resin decreases water sorption and solubility significantlycompared to pure PMMA Torres et al (2011) concludedthat PMMA-TiO

2-Fe2O3nanocomposites had lower sorption

and porosity values compared to pure PMMA but similarsolubility levels However the solubility levels were originallylow which is important to prevent the adverse effects on oralstructures or polymer functions [41] Also as thematerial getsmore homogenous it becomes less soluble with lower watersorption levels [29]

Therefore the addition of TiO2NP fills the microvoids

and polymer interstitial spaces decreasing the ability ofcomposite material to absorb water In addition to thatTiO2NP are insoluble in water and these particles partly

replace the hydrophilicmatrix which decreases water uptakeThe use of silane-coupling agent in silanization process ofTiO2NP could lead to a reduction in the amount of water that

reaches the inner layers of polymer matrix [18]

146 Thermal Properties The addition of 3 TiO2NP to

PMMA had no effect on thermal conductivity [25]The glasstransition temperature (Tg) test is done to understand thethermal stability and determine the temperature at whichthe material starts to degrade As the percentage of TiO

2NP

increases the Tg of nanocomposite increases linearly up to75wt TiO

2 Pure PMMA is stable up to 134∘C (1 weight

loss) while PMMA2wtTiO2and PMMA5wtTiO

2are

stable up to 154∘C and 180∘C respectively Tg was improvedby 15ndash34 with 2ndash5 addition of TiO

2NP respectively

However further addition of TiO2NP caused a decrease in

thermal stability [33] Another study by Safi (2014) reportedthe positive effect of TiO

2NP addition on the Tg temperature

of acrylic resin [51] In a recent study [43] authors evaluatedthe effect of adding 1 2 and 3 TiO

2NP to PMMA on

thermal behavior and found a slight effect on Tg degradationtemperature and rate

Chatterjee (2010) in another study reported that theaddition of 5wt TiO

2NP caused a 23 increase in Tg and

this improvement reached only 3 when the amount ofTiO2NPwas increased to 15 [9] Also pure PMMA showed

5 weight loss at 217∘C while a higher temperature (310∘C)was needed to create the same effect in the PMMA5wtTiO

2

[9] Recently Totu et al (2018) [14] confirmed the increasein decomposition temperature for PMMATiO

2NP compos-

ite suggesting an improved thermal stability This may beexplained by the reduced intercrystalline distance interac-tion and bond formation betweennanoparticles and polymerchains or the absorption of some energy by the titania par-ticles increasing the thermal stability Final decompositionof the PMMATiO

2NP composite happened at temperatures

620-700∘C with decreasing pattern of the total mass loss asthe amount of nanoparticles increased

The thermal stability of TiO2NP added to PMMA inhibits

the degradation of the resin and improves the thermalstability of the composite material [33] Another explanationfor thermal stability is the migration of TiO

2NP with low

surface energy to the surface of the PMMA resin to forma heat resistant layer [9] The decrease in thermal stabilitywith higher amount of nanofiller may be attributed to theagglomeration of filler particles rather than forming a filler-to-matrix interaction This agglomeration reduces the effectof heat retardation associated with TiO

2NP [33] TiO

2NP

crystalline phase has free electrons that can be associatedwithsurface reactions Oxygen that diffused in the nanocompositesamples was absorbed on the surface of TiO

2NP Hence

diffused oxygen amount in the PMMAmatrix was lower thanin pure PMMA which led to the slower thermooxidativedegradation of the PMMAmatrix [9 33]

It is knows that PMMA shrinks upon polymerizationcausing dimensional changes in the final product Dimen-sional stability is also affected by coefficient of thermalexpansion The result of a study by Hashem et al (2017)[22]showed that pure PMMA and PMMA3TiO

2started to

disintegrate and lose weight at 200∘C with 90 weightloss happening at 400∘C for both materials suggesting nosignificant effect of TiO

2NPon themelting temperature of the

composite material This might be explained by the minimalamount of filler addition or the presence of large number ofdecomposition sites within the material [22]

147 Viscoelastic Behavior Little work has been doneon the effects of TiO

2NP on the viscoelastic behavior

(creep-recovery and relaxation) behavior of PMMA matrixRecently in a study by Alrahlah done to investigate vis-coelastic properties of TiO

2NP-modified PMMA denture

base composite it was found that the creep-recovery andrelaxation behaviors of PMMA were significantly improveddue to the addition of TiO

2NPAlso the improvement further

increased as the concentration of the nanofiller changed from1 to 3This improvement in the behavior indicates the roleof the nanoparticles in increasing the stiffness of the PMMAmatrix owing to the reduction in its molecular mobility andfree volume [43]

148 Electrical Behavior It is imperative to avoid prolongedcontact between oral mucosa and materials with high elec-trical conductivity Metallic particles present in restorativematerials my produce a galvanic effect in the highly con-ductive oral environment causing oral discomfort changesin cell proliferation and immune markers [27 54] Totu andcolleagues (2018) [55] studied the effect of adding differentpercentages of TiO

2NP (0 (control) 02 04 06

10 20 25 and 5) to PMMA used for 3D printingon the electrical properties of the resulting nanocompositeThey reported a decrease in material resistance with theadditions of ge1 TiO

2NP Also an increase in electrical con-

ductivity was noted with the addition of 5 TiO2NP How-

ever the composite material still maintained its insulatingproperty

International Journal of Biomaterials 7

2 Overall Performanceand Clinical Significance

It is well understood that advancements in biomaterialscience affect the progression of technologies in any fieldincluding dental prostheses The introduction of nanomate-rials had significantly changed the clinical and technolog-ical aspects of dentistry In this paper the latest researchprogress on the applications of TiO

2NP in prosthodontics

was reviewed It clearly shows varying responses of phys-ical and mechanical properties of the modified materialswhere a number of properties improved others deterio-rated and few did not change Their level of effectivenessas shown in the literature is diverse being more or lesseffective than pure materials Therefore to attain removableprostheses with improved properties and acceptable clinicalperformance the material of manufacture (acrylic resin)can be enhanced by adding proper percentage of nanofillerinitial surface treatment of the nanoparticles and appro-priate selection of addition method Authors hope that thisreview article would provide some valuable elicitation forfuture scientific and technological innovations in the relatedfield

Based on this review TiO2NPwere found to be enhancers

in some aspects modifiers in some and insignificant in oth-ers The effect depends mainly on NP size addition methodsurface treatment and loading percentage Although the sizeof NP ranged between 5 nm and 350 nm the results of thestudies were not justified based on the nanofiller size anda clear link between size and effect was not established Forthat further investigations to relate the resulting propertiesto nanoparticle size are required

Variations in the results were mainly related to fillermode of addition The addition of nanoparticles to acrylicmonomer was considered more effective owing to betterdispersion of NP within the monomer In this method thedominant improvement was noticed in mechanical prop-erties while physical properties were slightly affected It isworth noting that with this technique the polymer monomerratio may be affected Therefore mixing the nanofillerwith acrylic powder has been suggested and studied Tillnow no study can be found that compares between theeffects of different modes of addition (nanofillers additionto powder or monomer) Based on this review furtherinvestigations of the above-mentioned point are necessaryas well as the proper way to establish the proportion ofpolymermonomer ratio for each method hence nanofilleraddition interferes with the manufacturersquos recommendedratios

The percentage of addition also plays a role in resultingproperties While the range of addition was very broad(05ndash30wt) low percentages resulted in improved prop-erties compared to higher percentages Simple addition of1ndash2wt ratios exhibited improved properties while increas-ing the filler content more than 5wt significantly weakenedthe final nanocomposites In fact the bonding betweenTiO2NP and resin matrix is a critical factor to achieve the

desired properties of nanocomposite As showed in Table 1the treatment of NPwith saline coupling agents improved the

properties in comparison to untreated particles ThereforeNP surface treatment is recommended

According to Table 1 inconsistencies in prepared spec-imen sizes for the same test were seen which may havecontributed to variations in the results between studiesexperimenting with the same filler percentage This reflectsa major error in the methodologies of the studies where thetest should have been done according to standardized spec-imensrsquo dimensions and testing procedures Testing shouldfollow an internationally accepted standardization proto-col like the ADA specifications for denture base polymersto make it possible to compare results between differentstudies

Titanium nanoparticles remain under focus because ofthe antimicrobial efficacy against candida species despitetheir negative effect on a number of properties Incorporationof TiO

2NP into PMMA matrix proved to have antimicrobial

effects specifically on candida species [24] Not to be lost inthis discussion is the effect of TiO

2NP surface modification

on antimicrobial properties of the final product It was shownthat modification with noble metals such as (Ag Au Ptand Pd) on TiO

2NP surface enhanced the photocatalytic

ability of the nanoparticles and bactericidal activity thereafter[12]

Even with this number of studies on recently introducedTiO2NP into PMMA no clear evidence on the clinical

applicability of this nanocomposite has been demonstratedFurther investigations are required to interpret and confirmthe chemical structure changes in PMMATiO

2nanocom-

posite and also to determine the need from otherwise forsurface treatment as well as the proper percentage of additionthat will not affect the final product adversely

Research to improve upon existing nanomaterials is stillongoing with emphasis on efficiency Although the sciencebehind nanotechnology is intriguing the lack of long-termevidence addressing their clinical performance restricts theirwide clinical use Overall there is an essential requirement toinvestigate the durability of these PMMATiO

2composites in

different environmental conditions to extend the applicabilityof these hybrid materials

3 Conclusion

Based on the current review we could conclude thatthe addition of TiO

2NP to PMMA denture bases is still

questionable for working as a reinforcing material andrequires further investigations following the ADA specifica-tions These investigations must explore the chemical andstructural changes happening in the nanocomposite afterTiO2addition The improvements in properties mentioned

above were dominantly seen with lower concentrations ofTiO2and the increase in the amount of added nanopar-

ticles caused adverse effects on resulting PMMATiO2

compositeIn conclusion there is an essential need to investigate the

clinical performance and durability of these nanocompositesin different conditions simulating the oral environment toverify their applicability and provide an insight of possiblefuture researches in this field

8 International Journal of Biomaterials

Table1TiO2NPapplications

indentureb

asea

ndits

effecto

nthetestedprop

ertie

s

Authorsyear

Particlesiz

eAd

ditio

npercentage

Type

ofAc

rylic

Nanocom

positep

reparatio

nProp

ertie

stested

Specim

ensiz

eEff

ects

(IncreaseD

ecreaseUnchanged)

Chatterje

e2010

[9]

5nm

0-15w

tPM

MAfro

mScientificP

olym

erProd

ucts(O

ntario

NY)

(i)MeasuredTiO2NPmixed

with

PMMAfor5

-10min

(ii)D

ACAtwin-screw

extractio

nprocessa

t190∘C

and100rpm

(iii)Ac

rylic

mixed

for6

-7min

andextrud

ed5tim

es

(i)Tensile

mod

ulus

(ii)D

imensio

nal

stability

(iii)Glasstransition

temperature(T

g)

(iv)U

Vabsorptio

n

10x6x03m

m

5mg

(i)Im

provem

entintensile

mod

ulus

(ii)Increased

thermalsta

bility

(iii)IncreasedT g

(iv)Improvem

entinUV

absorptio

n997888rarr

maxim

umat2

TiO2NP

Chatterje

e2010

[10]

5nm

0 20

50 75

100

150

300

PMMAfro

mScientificP

olym

erProd

ucts(O

ntario

NY)

(i)MeasuredTiO2NPmixed

with

PMMAfor5

-10min

(ii)D

ACAtwin-screw

extractio

nprocessa

t190∘C

and100rpm

(iii)Ac

rylic

mixed

for6

-7min

andextrud

ed5tim

es

(i)Glasstransition

temperature(T

g)

(ii)Th

ermalsta

bility

(iii)Decom

position

temperature

10x6x03m

m

(i)T g

increasedlin

early

upto

75TiO2NP

(ii)Th

ermalsta

bilityincreased

(2-15

TiO2NP)

(iii)Decom

position

temperaturesincreased

with

filler

contentu

pto

10TiO2NP

Aneho

suretal

2012

[11]

31nm

ldquoAnataseph

aserdquo

30

Inadditio

nto

surfa

cecoating

DPI

heatcure

acrylic

resin

(In

dia)

(i)Visib

lelig

htactiv

ated

TiO2NPwe

remixed

with

methylm

ethacrylate

mon

omer

(i)Microbial

inhibitory

effect

againstSA

ureus

5x5x2mm

(i)3w

of

TiO2show

santim

icrobialactiv

ityagainstS

Au

reus

Sodagare

tal2013

[12]

21nm

ldquoAnatase

phaserdquo

0 05 10

SelectaP

lus

(self-c

urea

crylic

resin

)

(i)TiO2NPwe

readdedto

acrylic

mon

omer

(i)Flexuralstr

ength

50x10

x33m

m(i)

Flexuralstr

engthdecreasedas

thefi

llerc

ontent

increased

(i)Flexuralmod

ulus

(i)Nochange

inflexu

ral

mod

ulus

Ham

ouda

and

Beyari

2014

[13]

21nm

50

Con

ventionalh

eat

cure

acrylic

resin

(AcrostonWHN

England)

andhigh

impact(M

etrocryl

HiMetrodent

LTDE

ngland

)

(i)TiO2NPwe

remixed

thorou

ghlywith

acrylic

powd

erby

hand

(ii)F

lexu

ral

strength

(iii)To

ughn

ess

65x10

x25mm

(ii)F

lexu

ralstre

ngth

and

toug

hnessd

ecreased

(iv)M

onom

errelease

(iii)Nodifferenceb

etwe

encontroland

TiO2reinforced

regardingmon

omer

release

International Journal of Biomaterials 9

Table1Con

tinued

Authorsyear

Particlesiz

eAd

ditio

npercentage

Type

ofAc

rylic

Nanocom

positep

reparatio

nProp

ertie

stested

Specim

ensiz

eEff

ects

(IncreaseD

ecreaseUnchanged)

Nazirk

aretal

2014

[14]

7nm

ldquoAnatase

phaserdquo

0 05 10

DPI

heatcure

acrylic

resin

(i)TiO2NPaddedto

acrylic

mon

omer

(i)Flexuralstr

ength

65x10

x33mm

(i)Flexuralstr

engthdecreasedas

theT

iO2am

ount

increased

Shirk

avandand

Moslehifard2014

[15]

lt25

nm(averagesim204

nm)

ldquoAnataseand

Rutilep

hasesrdquo

0 05 10

20

Heatcurea

crylic

resin

from

Ivoclar

Vivadent

(i)TiO2NPwe

remixed

with

thea

crylicresin

polymer

inan

amalgamator

for2

0min

(i)Tensile

strength

60x12

x4mm

(i)Tensile

strengthandelastic

mod

ulus

improved

with

1TiO2NP

(ii)0

5and2

TiO2we

reno

tsig

nificantly

different

from

each

othero

rcon

trol

Harinietal2014

[16]

0 10

20

50

Clearh

eatcure

acrylic

resin

(i)Nanop

artic

lesw

ere

incorporated

into

mon

omer

byultrason

icdispersio

n(i)

Flexuralstr

ength

65x10

x3mm

(i)Flexuralstr

engthim

proved

with

TiO2additio

nsig

nificant

differencen

oticed

with

5

Safi2014

[17]

50

Heatcured

enture

base

acrylic

(Sup

eracrylplus

Czecho

slovakia)

(i)Nanop

artic

lesa

dded

tomon

omer

andsonically

dispersed

(i)Coefficientof

thermalexpansion

(ii)M

odulus

(iii)Glasstransition

15x6mm

Cylin

ders

65x10

x25mm

Powd

erform

(10g)

(i)Decreaseincoeffi

cientof

thermalexpansion

(ii)D

ecreased

inmod

ulus

ofelastic

ity

(iii)IncreasedT g

Alwanand

Alameer2015

[18]

lt50

nmsiz

e0 30

(i)Silanizedwith

TMSP

M

Heatcurea

crylic

resin

(i)SilanizedTiO2NPwe

readdedto

mon

omer

and

sonicated

(i)Im

pactstr

ength

(ii)T

ransverse

strength

(iii)Hardn

ess

(iv)S

urface

roug

hness

(v)W

atersorptio

nandsolubility

80x10

x4mm

65x10x25m

m

50x05m

mdisc

(i)Increased

(ii)Increased

(iii)Increased

(iv)Increased

(v)D

ecreased

10 International Journal of Biomaterials

Table1Con

tinued

Authorsyear

Particlesiz

eAd

ditio

npercentage

Type

ofAc

rylic

Nanocom

positep

reparatio

nProp

ertie

stested

Specim

ensiz

eEff

ects

(IncreaseD

ecreaseUnchanged)

Ahm

edetal2016

[19]

46nm

0 10

50

Con

ventionalh

eat

cure

acrylic

resin

(ImplacrylVe

rtex)

andhigh

impact

heatcureacrylic

resin

(Vertex-Dental

Netherla

nds)

(i)TiO2NPwe

readdedinto

acrylic

resin

(i)Flexuralstr

ength

(ii)Impactstr

ength

(iii)Hardn

ess

50x10

x3mm

60x6x4mm

25x10

x3mm

(i)Decreased

with

TiO2

additio

n

(ii)Increased

onlyfor

conventio

nalacrylicresin

mod

ified

by1

(iii)Increasedwith

5additio

nTiO2NPforb

othtypeso

facrylic

Sodagare

tal2016

[20]

21nm

05 10

SelectaP

lus

(self-c

urea

crylic

resin

)

(i)Nanop

artic

lesw

erea

dded

toacrylic

mon

omer

and

stirred

(i)Antim

icrobial

prop

ertie

s20

x20

x1m

m

(i)TiO2redu

cedmicrobial

grow

thatbo

thconcentrations

at90

min

underU

VAexpo

sure

(ii)A

ntim

icrobialactiv

ityof

TiO2istim

edependent

Ahm

edetal2017

[21]

lt25

nm0 05 10

Heatcurea

crylic

resin

from

Dentsp

lyInternationalInc

(ChicagoIL

USA

)

(i)TiO2NPwe

readdedto

acrylic

polymer

andmixed

usingam

algam

capsule

(i)Flexuralstr

ength

(ii)F

racture

toug

hness

(iii)Hardn

ess

65x10

x25mm

65x10

x25mm

30x10

x25mm

(i)Increasedwith

both

filler

percentages

(ii)N

oeffecto

nfracture

toug

hnesso

fbothfiller

percentages

(iii)Increasedwith

1filler

Hashem

etal2

017

[22]

90nm

0 10

20 30

Self-cureacrylic

resin

from

Eco-crylcold

Protechn

o(Spain)

(i)TiO2NPwe

remixed

with

them

onom

er

(i)Flexuralmod

ulus

andflexu

ral

strength

(ii)H

ardn

ess

(iii)Surfa

cewe

tting

30x8x1m

m

50x1m

mdiscs

(i)Increasedlin

early

(ii)Increased

(iii)Re

ducedwith

1filler

contentand

increasedwith

high

erpercentages

(iv)T

gdecreasedwith

TiO2

additio

n

Ghahrem

anietal

2017

[23]

20-30nm

ldquoAnatase

phaserdquo

0 10

SRTriplexHot

heatcureacrylic

resin

(Ivoclar

Vivadent

Inc

Schaan

Liechtenste

in)

(i)TiO2NPwe

remixed

with

acrylic

resin

powd

erin

anultrason

icmixer

(i)Tensile

strength

(ii)Impactstr

ength

60x12

x39mm

75x10

x10

mm

(i)Increased

(ii)Increased

International Journal of Biomaterials 11Ta

ble1Con

tinued

Authorsyear

Particlesiz

eAd

ditio

npercentage

Type

ofAc

rylic

Nanocom

positep

reparatio

nProp

ertie

stested

Specim

ensiz

eEff

ects

(IncreaseD

ecreaseUnchanged)

Totu

etal2017

[24]

65-170

nm

0 02

04 1 25

PMMA+P

EMAfor

3Dprintin

g(eDent

100En

visio

nTec

GmbH

Gladb

eck

Germany)

(i)Nanop

artic

lesw

erea

dded

into

PMMAsolutio

nwith

continuo

usstirringand

ultrason

icmixingfor1

hour

(i)Antim

icrobial

effect(Ca

ndida

scotti)

(ii)C

omplete

denture

manufacturin

gusin

gste

reolith

ograph

y

(i)041

and25

inhibited

cand

idagrow

th

(ii)P

MMA04TiO2compo

site

successfu

llyused

ford

enture

fabrication

Aziz2018

[25]

30nm

0 30

Highim

pactheat

cure

acrylic

resin

(Vertex-Dental

Netherla

nds)-

(i)TiO2NPwe

redispersedin

mon

omer

andsonicatedat

120W

and60

KHzfor

3minutes

(i)Im

pactstr

ength

(ii)C

olor

stability

(iii)Th

ermal

cond

uctiv

ity

80x10

x4mm

35x15

x05mm

40x25mm

(i)Increased

(ii)Increased

colorstabilityfor

testgrou

ps

(iii)Noeffect

Alra

hlah

etal

2018

[26]

80-100

nm

0 1 2 3

Heatcurea

crylic

resin

(Lucito

ne550Dentsp

lyInt

IncPaU

SA)

(i)Hardn

essa

ndmod

ulus

(ii)T

gdegradation

temperatureand

rate

(iii)Cr

eep-recovery

andrelaxatio

nbehavior

(iv)A

ntibacteria

ladhesio

n

50x10

mm

discs

cutindifferent

sizes

ford

ifferent

tests

7mg

5x10

mm

(i)Increased

(ii)S

light

increase

with

2nano

-fillerc

ontent

(iii)Im

provem

entinbehavior

(iv)D

ecreaseinbacterial

attachmentcon

tent

Karcietal2018

[27]

13nm

0 1 3 5

(i)Au

to-polyeriz

ed(H

eraeus

Kulze

rNew

bury

Berkshire

UK)

(ii)

Heat-p

olym

erized

Heraeus

Kulze

rNew

bury

Berkshire

UK

(iii)Microwave-

polymerized

(GC

DentalTo

kyo

Japan)

(i)TiO2NPwe

remixed

with

acrylic

resin

powd

erusing

ballmillingat40

0rpm

for2

hours

(i)Flexuralstr

ength

65x10

x3mm

(i)Increasedforh

eat-and

auto-polym

erized

acrylic

at1

(ii)D

ecreased

fora

lltypeso

facrylic

at5

12 International Journal of Biomaterials

Table1Con

tinued

Authorsyear

Particlesiz

eAd

ditio

npercentage

Type

ofAc

rylic

Nanocom

positep

reparatio

nProp

ertie

stested

Specim

ensiz

eEff

ects

(IncreaseD

ecreaseUnchanged)

Totu

etalTo

tuet

al2

017[28]

ldquoAnatase

phaserdquo

0 02

04

06 10

25

(i)PM

MA-

MA

(ii)P

MMA-

MMA-

BPO

(iii)3D

printed

PMMA(eD

Envisio

nTec

GmbH

Gladb

eck

Germany)

(i)TiO2mod

ified

bymethacrylicacid

then

manually

mixed

with

PMMAmixture

(i)Th

ermalsta

bility

(ii)T

g

Stereolitho

graphic

dentures

(i)Increased(im

proved)

(ii)Increased

Totu

etal2018

[29]

ldquoAnatase

phaserdquo

0 02

04

06 10

20 25 50

PMMAfor3

Dprintin

g(eDent

100En

visio

nTec

GmbH

Gladb

eck

Germany)

(i)Re

sistance

(ii)E

lectric

alcond

uctiv

ity

(iii)Dielectric

constant

(i)Decreased

with

1020

25

and5

(ii)Increased

butm

aterialstill

maintainedinsulatin

gprop

ertie

s

(iii)Increasedwith

5

International Journal of Biomaterials 13

Conflicts of Interest

The authors declare that they have no conflicts of interest

References

[1] R L Sakaguchi and J M Powers Craigrsquos Restorative DentalMaterials Elsevier Health Sciences Philadelphia PA USA pp163-176 2012

[2] N Murakami N Wakabayashi R Matsushima A Kishidaand Y Igarashi ldquoEffect of high-pressure polymerization onmechanical properties of PMMA denture base resinrdquo Journalof the Mechanical Behavior of Biomedical Materials vol 20 pp98ndash104 2013

[3] R Adhikari and G H Michler ldquoPolymer nanocompositescharacterization by microscopyrdquo Polymer Reviews vol 49 no3 pp 141ndash180 2009

[4] A Navidfar T Azdast and A Karimzad Ghavidel ldquoInfluenceof processing condition and carbon nanotube on mechani-cal properties of injection molded multi-walled carbon nan-otubepoly(methyl methacrylate) nanocompositesrdquo Journal ofApplied Polymer Science vol 133 no 31 Article ID 43738 pp1ndash9 2016

[5] P Chaijareenont H Takahashi N Nishiyama and M Ark-sornnukit ldquoEffect of different amounts of 3-methacryloxypro-pyltrimethoxysilane on the flexural properties and wear resis-tance of alumina reinforced PMMArdquo Dental Materials vol 31no 4 pp 623ndash628 2012

[6] J Jordan K I Jacob R TannenbaumMA Sharaf and I JasiukldquoExperimental trends in polymer nanocompositesmdasha reviewrdquoMaterials Science and Engineering A vol 393 no 1-2 pp 1ndash112005

[7] MMGad SM Fouda F A Al-Harbi RNapankangas andARaustia ldquoPMMAdenture base material enhancement A reviewof fiber filler and nanofiller additionrdquo International Journal ofNanomedicine vol 12 pp 3801ndash3812 2017

[8] F Li S Zhou B You and L Wu ldquoKinetic study onthe UV-induced photopolymerization of epoxy acrylateTiO2nanocomposites by FTIR spectroscopyrdquo Journal of AppliedPolymer Science vol 99 no 6 pp 3281ndash3287 2006

[9] A Chatterjee ldquoProperties improvement of PMMA using nanoTiO2rdquo Journal of Applied Polymer Science vol 118 no 5 pp2890ndash2897 2010

[10] P Harini K Mohamed and T V Padmanabhan ldquoEffect ofTitanium dioxide nanoparticles on the flexural strength ofpolymethylmethacrylate An in vitro studyrdquo Indian Journal ofDental Research vol 25 no 4 pp 459ndash463 2014

[11] G Venkatesh Anehosur R D Kulkarni M G Naik et alldquoSynthesis and Determination of Antimicrobial Activity ofVisible Light Activated TiO2 Nanoparticles with PolymethylMethacrylate Denture Base Resin Against StaphylococcusAureusrdquo Journal of Gerontology ampGeriatric Research vol 01 no01 pp 103ndash111 2012

[12] A Sodagar A Bahador S Khalil A Saffar Shahroudi and MZaman Kassaee ldquoThe effect of TiO

2and SiO

2nanoparticles on

flexural strength of poly (methyl methacrylate) acrylic resinsrdquoJournal of Prosthodontic Research vol 57 no 1 pp 15ndash19 2013

[13] I M Hamouda and M M Beyari ldquoAddition of glass fibers andtitanium dioxide nanoparticles to the acrylic resin denture basematerial comparative study with the conventional and highimpact typesrdquo Oral Health and Dental Management vol 13 pp107ndash112 2014

[14] E E Totu C M Cristache E Voicila et al ldquoOn physicaland chemical characteristics of Poly(methylmethacrylate) na-nocomposites for dental applications IrdquoMateriale Plastice vol54 no 4 pp 666ndash672 2017

[15] S Shirkavand and EMoslehifard ldquoEffect of TiO2 nanoparticleson tensile strength of dental acrylic resinsrdquo Journal of DentalResearch Dental Clinics Dental Prospects vol 8 no 4 pp 197ndash203 2014

[16] M Karci N Demir and S Yazman ldquoEvaluation of FlexuralStrength of Different Denture Base Materials Reinforced withDifferent Nanoparticlesrdquo Journal of Prosthodontics 2018

[17] O Gurbuz F Unalan and I Dikbas ldquoComparison of thetransverse strength of six acrylic denture resinsrdquo OhdmbscMagazines vol 9 pp 21ndash24 2010

[18] S A Alwan and S S Alameer ldquoThe Effect of the Addition ofSilanized Nano Titania Fillers on Some Physical and Mechan-ical Properties of Heat Cured Acrylic Denture Base MaterialsrdquoJournal of Baghdad College of Dentistry vol 27 no 1 pp 86ndash912015

[19] M Ashour Ahmed M El-Shennawy Y M Althomali andA A Omar ldquoEffect of Titanium Dioxide Nano Particles In-corporation on Mechanical and Physical Properties on TwoDifferent Types of Acrylic Resin Denture Baserdquo World Journalof Nanoscience and Engineering vol 06 no 03 pp 111ndash119 2016

[20] A Sodagar S Khalil M Z Kassaee A S Shahroudi B Pourak-bari and A Bahador ldquoAntimicrobial properties of poly (methylmethacrylate) acrylic resins incorporated with silicon dioxideand titanium dioxide nanoparticles on cariogenic bacteriardquoJournal of Orthodontic Science vol 5 no 1 pp 7ndash13 2016

[21] M A Ahmed A A Omar M El-Shennawy M I Ebrahimand Y M Althomali ldquoInfluence of addition of different types ofnano-fillers on the microstructure and mechanical propertiesof PMMA based denture resinrdquo Kasmera Journal vol 45 pp48ndash59 2017

[22] MHashemM F Al Rez H Fouad et al ldquoInfluence of titaniumoxide nanoparticles on the physical and thermomechanicalbehavior of poly methyl methacrylate (pmma) A denture baseresinrdquo Science of Advanced Materials vol 9 no 6 pp 938ndash9442017

[23] L Ghahremani S Shirkavand F Akbari and N SabzikarildquoTensile strength and impact strength of color modified acrylicresin reinforcedwith titaniumdioxide nanoparticlesrdquo Journal ofClinical and Experimental Dentistry vol 9 no 5 pp e661ndashe6652017

[24] E E Totu A C Nechifor G Nechifor H Y Aboul-Eneinand C M Cristache ldquoPoly(methyl methacrylate) with TiO2nanoparticles inclusion for stereolitographic complete denturemanufacturing minus the fututre in dental care for elderly edentu-lous patientsrdquo Journal of Dentistry vol 59 pp 68ndash77 2017

[25] H K Aziz ldquoTiO-Nanofillers Effects on Some Properties ofHighly- Impact Resin Using Different Processing TechniquesrdquoThe Open Dentistry Journal vol 12 no 1 pp 202ndash212 2018

[26] M Tsuji T Ueda K Sawaki M Kawaguchi and K SakuraildquoBiocompatibility of a titanium dioxide-coating method fordenture base acrylic resinrdquo Gerodontology vol 33 no 4 pp539ndash544 2016

[27] S PodzimekM Tomka P Sommerova Y Lyuya-Mi J Bartovaand J Prochazkova ldquoImmune markers in oral discomfortpatients before and after elimination of oral galvanismrdquo Neu-roendocrinology Letters vol 34 no 8 pp 802ndash808 2013

[28] S Kiat-amnuayM Beerbower JM Powers andRD ParavinaldquoInfluence of pigments and opacifiers on color stability of

14 International Journal of Biomaterials

siliconemaxillofacial elastomerrdquo Journal ofDentistry vol 37 no1 pp e45ndashe50 2009

[29] S H Tuna F Keyf H O Gumus and C Uzun ldquoThe evaluationof water sorptionsolubility of various acrylic resinsrdquo EuropeanJournal of Dental Education vol 2 pp 191ndash197 2008

[30] S M Khaled R Sui P A Charpentier and A S RizkallaldquoSynthesis of TiO

2-PMMA nanocomposite using methacrylic

acid as a coupling agentrdquo Langmuir vol 23 no 7 pp 3988ndash39952007

[31] L Reijnders ldquoThe release of TiO2 and SiO2 nanoparticles fromnanocompositesrdquo Polymer Degradation and Stability vol 94no 5 pp 873ndash876 2009

[32] G Nazirkar S Bhanushali S Singh B Pattanaik and N RajldquoEffect of Anatase Titanium Dioxide Nanoparticles on theFlexural Strength of Heat Cured Poly Methyl MethacrylateResins An In-Vitro Studyrdquo Journal of Indian ProsthodontistSociety vol 14 pp 144ndash149 2014

[33] A Chatterjee ldquoEffect of nanoTiO2addition on poly(methyl

methacrylate) an exciting nanocompositerdquo Journal of AppliedPolymer Science vol 116 no 6 pp 3396ndash3407 2010

[34] S Rashahmadi R Hasanzadeh and S Mosalman ldquoImprov-ing the Mechanical Properties of Poly Methyl MethacrylateNanocomposites for Dentistry Applications Reinforced withDifferent Nanoparticlesrdquo PolymermdashPlastics Technology andEngineering vol 56 no 16 pp 1730ndash1740 2017

[35] A H Yuwono B Liu J Xue et al ldquoControlling the crystallinityand nonlinear optical properties of transparent TiO

2-PMMA

nanohybridsrdquo Journal of Materials Chemistry vol 14 no 20 pp2978ndash2987 2004

[36] J K Pandey K RaghunathaReddy A P Kumar andR P SinghldquoAn overviewon the degradability of polymer nanocompositesrdquoPolymer Degradation and Stability vol 88 no 2 pp 234ndash2502005

[37] C Tao S Jianping J Weng L Ting and H Xiaozhu ldquoPrepara-tion and properties of PMMATiO2 nanocompositerdquoChemicalReaction Engineering andTechnology vol 23 pp 435ndash440 2007

[38] A H Yuwono J Xue J Wang et al ldquoTransparent nanohybridsof nanocrystalline TiO2 in PMMA with unique nonlinearoptical behaviorrdquo Journal of Materials Chemistry vol 13 no 6pp 1475ndash1479 2003

[39] R Alla K N Raghavendra R Vyas and A KonakanchildquoConventional and contemporary polymers for the fabricationof denture prosthesis Part I overview composition and proper-tiesrdquo International Journal of Applied Dental Sciences vol 1 noPart I pp 82ndash89 2015

[40] C C Trapalis P Keivanidis G Kordas et al ldquoTiO2(Fe3+)nanostructured thin films with antibacterial propertiesrdquo ThinSolid Films vol 433 no 1-2 pp 186ndash190 2003

[41] L S Acosta-Torres L M Lopez-Marın R E Nunez-Anita GHernandez-Padron and V M Castano ldquoBiocompatible Metal-Oxide Nanoparticles Nanotechnology Improvement of Con-ventional Prosthetic Acrylic Resinsrdquo Journal of Nanomaterialsvol 2011 Article ID 941561 8 pages 2011

[42] A Bahador S Khalil B Pourakbari et al ldquoPhotocatalyticEffects of Acrylic Resins Incorporated with Nano-titaniumDioxide on Planktonic and Biofilm Growth of Four CariogenicBacteriardquo Annual Research amp Review in Biology vol 4 no 17pp 2695ndash2708 2014

[43] A Alrahlah H Fouad M Hashem A Niazy and A AlBadahldquoTitanium Oxide (TiO2)Polymethylmethacrylate (PMMA)Denture Base Nanocomposites Mechanical Viscoelastic and

Antibacterial BehaviorrdquoMaterials vol 11 no 7 Article ID 1096pp 10961ndash109615 2018

[44] A Kubacka M Ferrer M L Cerrada et al ldquoBoostingTiO2-anatase antimicrobial activity Polymer-oxide thin filmsrdquoApplied Catalysis B Environmental vol 89 no 3-4 pp 441ndash4472009

[45] Y Cheng T Sakai R Moroi et al ldquoSelf-cleaning abilityof a photocatalyst-containing denture base materialrdquo DentalMaterials vol 27 no 2 pp 179ndash186 2008

[46] C M Bollen P Lambrechts and M Quirynen ldquoComparisonof surface roughness of oral hard materials to the thresholdsurface roughness for bacterial plaque retention a review of theliteraturerdquoDental Materials vol 13 no 4 pp 258ndash269 1997

[47] N Elshereksi M Ghazali A Muchtar and C Azhari ldquoEffectof nanobarium titanate addition on the surface characteristicsof denture base resinrdquo International Journal of Mechanical andProduction Engineering vol 5 pp 1ndash8 2017

[48] Y Xia Z Feimin H Xie and N Gu ldquoNanoparticles reinforcedresin based dental compositesrdquo Journal of Dentistry vol 36 pp450ndash455 2008

[49] S Mosalman S Rashahmadi and R Hasanzadeh ldquoThe effectof TiO2 nanoparticles on mechanical properties of poly methylmethacrylate nanocompositesrdquo International Journal of Engi-neering Transactions B Applications vol 30 no 5 pp 807ndash8132017

[50] Y Han S Kiat-amnuay J M Powers and Y Zhao ldquoEffectof nano-oxide concentration on the mechanical properties ofa maxillofacial silicone elastomerrdquo The Journal of ProstheticDentistry vol 100 no 6 pp 465ndash473 2008

[51] I N Safi ldquoEvaluation the effect of nanomdashfillers (TiO2 AL2O3

SiO2) addition on glass transition temperature E-moudulus

and coefficient of thermal expansion of acrylic denture basematerialrdquo Journal of Baghdad College of Dentistry vol 26 no1 pp 37ndash41 2014

[52] W Wang S Liao Y Zhu M Liu Q Zhao and Y Fu ldquoRecentApplications of Nanomaterials in Prosthodonticsrdquo Journal ofNanomaterials vol 2015 Article ID 408643 11 pages 2015

[53] L Sun R F Gibson F Gordaninejad and J Suhr ldquoEnergyabsorption capability of nanocomposites A reviewrdquoCompositesScience and Technology vol 69 no 14 pp 2392ndash2409 2009

[54] S Podzimek K Hana M Miksovsky et al ldquoThe Influence ofgalvanic currents and voltage on the proliferation activity oflymphocytes and expression of cell surface moleculesrdquo FoliaBiologica vol 54 no 5 pp 146ndash150 2008

[55] E E Totu E Voicila V Pistritu G Nechifor and C MCristache ldquoEvaluation of electrical characteristics for PMMA-TiO2 nanocomposites used in dentistryrdquo Evista de Chimie vol69 no 1 pp 155ndash159 2018

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Journal ofNanomaterials

Submit your manuscripts atwwwhindawicom

4 International Journal of Biomaterials

141 Antimicrobial Activities TiO2NP were found to have

an intrinsic antimicrobial property due the production ofcytotoxic oxygen radicles [26] TiO

2NP are ideal additives

because of their nontoxicity and chemical stability Howeverunder certain conditions they have an antimicrobial ability[41] When they are exposed to UV-light in the presenceof oxygen and water they decompose and oxidize othercompounds organic and inorganic Therefore they canbe considered as antimicrobial additive [41] FurthermoreTiO2NP had the ability to inhibit the adherence of cariogenic

bacteria in planktonic phase as well as in later phases ofbiofilm formation The addition of TiO

2NP to PMMA resin

used for dentures or other oral appliances will have a positiveeffect against microbial colonization [42]

Anehosur et al (2012) found that the addition of 3wt TiO

2NP to PMMA produced a positive antimicrobial

effect It had the ability to reduce microbial number whichprevents quorum sensing thereby halts plaque formationon PMMATiO

2nanocomposite surface [11] Due to the

photocatalytic property againstmicroorganisms patients willbe able to maintain the hygiene of their dentures easilyby exposing them to solar energylight sources to activatethe TiO

2NP [11] On the same way Alrahlah et al (2018)

reported a 50 and 90 decrease in bacterial cell attach-ment of E faecalis and P aeruginosa respectively with themere addition of 3 TiO

2NP [43] Likewise Totu et al

(2017) investigated the effect of incorporating TiO2NP into

a 3D-printed PMMA denture in an attempt to improvedenture antimicrobial characteristics and found that even thesmall addition of 04 of TiO

2NP to PMMA resulted in a

nanocomposite that prevented the colonization of microor-ganisms and further formation of biofilm [24] As a resultTiO2NP could be incorporated into denture PMMA resin to

successfully fabricate antimicrobial dentures [24] The largeactive surface area of the nanoparticles compared to theirsmall size makes them highly effective in low percentagesof addition It was found that as low as 04 1 and 25TiO2NP inhibited the growth of Candida As reported in

the literature TiO2NP caused a halt in the cellular enzymes

and increased cell wall permeability causing cell death[44]

Few studies reported that the addition of asmuch as 5wtTiO2NP to the PMMA is needed to achieve the antimicrobial

effect [45] However with this addition structural decompo-sition and material weakening may occur [26]

142 Surface Properties Surface microtopography of thedenture is a very important feature inmicrobial adhesion andplaque formation and subsequently denture stomatitis

(1) Surface Roughness Denture wearers have high prevalenceof poor oral health This is mostly caused by the surfacecontours of the dentures and the irregularities of the oralmucosa [45] Many factors were found to have an effect onthe surface roughness (Ra) of denture bases one of whichis the reinforcing material of the acrylic resin [46] Alwanand Alameer (2015) found an increase in surface roughnesswith the addition of 3wt of TiO

2NP to PMMA denture

base material and attributed this increase to the presence ofnanoparticles on the surface of specimens [18]

To establish a relation between contact angle (wetting)and the amount of TiO

2NPfiller in the PMMAresin Hashem

et al (2017) found that it is dependent on filler amountThe addition of 1wt TiO

2NP led to a reduction in surface

wetting while the addition of more filler improved wettingThis finding confirms the effect of fillers on the surfaceof composite material compared to the pure counterpart[22]

While few investigations weremade on surface roughnessof PMMATiO

2nanocomposite a significant increase was

reported compared to pure PMMA [18] As the surface getsrougher and Ra values increase the surface area increasesmeaning more sites are available for microbial adhesion andcolonization One of the most common organisms to beharbored on the surface of acrylic denture bases isC Albicans[47] Studies have reported that the surface roughness ofa denture should not exceed 02 120583m [45] Although thereis a direct relation between surface roughness and candidaadhesion (increased roughness increases candida adhesion)the reduction in candida count confirms the antifungalproperties of TiO

2NP

(2) Hardness Reports have confirmed that TiO2NP im-

proved the hardness of heat cure PMMA [10 18] Xia etal (2008) attributed the increase in surface hardness totwo factors proper filler content and use of silane-couplingagent which increases the bonding between filler and resinmatrix [48]The effect on surface hardness was detected withadditions of TiO

2NP as low as 1 [21] In another study

investigating the addition of 05 1 and 2 hardnessvalues were found to increase with the addition and thehighest values were seen with 2wt TiO

2 Mosalman et al

(2017) related this to increased number of bonds betweenmatrix and fillers which requires more energy to break thesebonds [49] Hashem et al (2017) reported an increase inhardness values that reached 20 30 and 34 more thanpure PMMA with 1 2 and 3 TiO

2NP respectively This

was explained by the increase in material stiffness due topresence of rigid particles within the matrix in addition toreduction of matrix mobility [22]

Alwan and Alameer (2015) concluded that 3 additionof TiO

2caused a significant increase in surface hardness

compared to pure PMMA [18] while Ahmed et al (2016)suggested the need of adding 5 TiO

2NP to increase surface

hardness of conventional and high impact heat cure acrylicresin to remarkable values [19] More recently Alrahlah et al(2018) confirmed the increase in surface hardness of up to35 with 3 TiO

2NP addition The values of the hardness

measurements were higher at the surface of the compositeresin and decreased as we move inward toward the core ofthe material suggesting higher crosslinking at the surface[43] Regarding selection of the most appropriate concen-tration of filler for inclusion within denture resin results ofmulticriteria decision making (MCDM) method suggestedthat a filler content in the range of 2wt would create acomposite material with improved mechanical propertiesincluding surface hardness [34]

International Journal of Biomaterials 5

143 Mechanical Properties

(1) Flexural Properties During function oral appliancesincluding dentures are exposed to a magnitude of deformingstresses and any factor that increases the deformation of thedenture base may lead to fracture [17] One of the factorsthat may change the amount of denture deformation is theadditive into the PMMA resinThe effect of TiO2NP additionon flexural strength of PMMA is partially dependent onthe type of acrylics and the concentration of nanoparti-cles [19] In 2013 Sodagar et al investigated the effect ofadding 05 and 1 TiO2NP into PMMA and reporteda decrease in flexural strength PMMA containing 05wtshowed the lowest values It was concluded that there isan inverse relation between the concentration of the fillerand the flexural strength of reinforced PMMA [12] Hanet al (2008) reached the same conclusion and related theresults to agglomeration of particles within the matrix whichmakes them stress concentrations areas [50] Other studiesalso reported a reduction in flexural strength [13 19 32]and modulus of elasticity [51] with the addition of TiO

2NP

Hamouda et al (2014) found that TiO2NP caused a reduction

in flexural strength with no change in flexural modulus [13]In the same token Nazirkar et al in (2014) were exploringthe effect of adding TiO

2NP into heat cure acrylic resin on

antimicrobial properties and reported an adverse effect onflexural strength of the final product [32]

In contrast to previous studies superior flexural proper-ties were reported with different concentrations of TiO

2NP

added to PMMA than those of normal PMMA [10 18 21 52]This improvement may be attributed to the effect of silaniza-tion of TiO

2NP [18] or the good dispersion of fillers within

the matrix which improves modulus transverse strengthand ductility [18 52] Hashem et al (2017) found that with05ndash3wt TiO

2NP addition flexural strength and modulus

increased Moreover they suggested that reinforced PMMAcould offer superior chemical and mechanical propertiesmaking it a better option for dentures than pure PMMA resin[22] On the same way Rashahmadi et al (2017) found thatthe mere addition of 05 TiO

2NP improved the flexural

strength and Youngrsquos modulus by 4 Based on MCDMresults TiO

2NP addition to PMMA is an excellent option

for improving properties of PMMA for dental applicationsespecially in 2wt concentration [34] In a recent studyby Karci et al (2018) [16] different types (heat- auto- andmicrowave polymerized) of acrylic mixed with 1 3 and5 nanotio2 were used to test the flexural strength of theresulting composite That study came to a conclusion thatthe addition of 1 TiO

2NP to heat- and autopolymerized

acrylic could improve the flexural strength while it remainedunchanged with 3 TiO

2NP and decreased with 5 for all

types of acrylicThiswas explained by the increase in agglom-eration of nanoparticles at higher addition percentages

In a study by Mosalman et al (2017) various percentagesof TiO

2NP (05 1 and 2wt ) were added to pure PMMA

and found that the flexural strength of all groups stayedunchanged Sampleswith 05wtTiO

2NP showed only 375

improvement in flexural strength compared to pure PMMAYoungrsquos modulus for all groups was improved with the

highest value seen in samples containing 2wt TiO2NP

[49]

(2) Impact Strength With regard to impact strength theaddition of TiO

2NP to heat cured acrylic resin resulted

in a positive effect compared to pure PMMA [18] Studieshave confirmed this finding with different concentrationsof TiO

2NP including 1 [19 23] 2wt[34 49] and 3wt

[25] The same finding was reported after the addition ofsilanized TiO

2NP [53] The detected increase in impact

strength was justified by good bonding between PMMAmatrix and TiO

2nanofillers These fillers reside in small

voids between polymer chains and result in slow segmentalmotion Also they provide large surface area due to theirsmall size which helps in energy dissipation [25] Otherssuggested that the nanofillers in the acrylic resin toleratemost of the applied load while the resin matrix helps instructural integrity and load distribution which eventuallyinhibits crack propagation [23]

(3) Tensile Strength Shirkavand and Moslehifard (2014)investigated the effect of 05wt 1wt and 2wt TiO

2NP

on tensile strength of PMMA base resins and found that thetensile strength of nanocomposite was the highest with 1wtTiO2NP and the improvement was 35 more compared to

pure PMMA However further increase in TiO2NP content

led to an adverse effect [15] due to clustering of TiO2NP

The fillers work as impurities and act as defects and stressconcentration centers [15 49] The same results were alsoreported by Ghaheremani et al (2017) [23] The increase intensile strength is probably attributed to the fact that follow-ing the incorporation of nanoparticles into acrylic powderthe applied load is mainly tolerated by these nanoparticles

Contrary to previous studies Chatterjee in 2010 foundthat nanocomposite with filler content as high as 5wt and15wt had a 59 and 95 increase in tensile modulusrespectively compared to that of pure PMMA [9] This wascaused by the strong adhesion between TiO

2NP and PMMA

The applied load is transferred through these interfacialsurfaces to the strongest material that is the nanoparticles [9]

144 Color Stability It is noteworthy that the reinforcingfiller material should ideally improve the mechanical proper-ties without causing an adverse reaction to the aesthetics [2541] TiO

2NP have whitish color therefore the appropriate

percentage of this additive that fulfills the aforementionedrequirement should be considered An objective evaluation ofthe color change is usually done using a spectrophotometerwhere the difference between light absorption between dif-ferent samples is calculated [28] Aziz in 2018 evaluated thecolor change after adding 3wt of TiO

2NP and found that

the amount of light absorbed increasedmaking the reinforcedspecimens more opaque compared to pure PMMA Thischange was due to the presence of TiO

2NP within the

matrix which absorbs more light than polymer matrix duehigh atomic number [25] Further studies are required todetermine the proper TiO

2NP percentage needed to attain

a PMMATiO2nanocomposite with superior properties and

acceptable aesthetics

6 International Journal of Biomaterials

145 Water Sorption Solubility and Porosity Conventionalacrylic resins have voids and porosities that allow watermolecules exchange which could be the leading cause forwater sorption and solubility [18]The nature of denture resinmaterial allows it to absorb water which acts as a plasticizerand affects the material dimensional stability and denturedurability [41]Thewatermolecules force themselves betweenpolymer chains move them apart create internal stressesand result in crack formation [29] As reported by Alwan andAlameer [18] the addition of TiO

2NP to heat cure acrylic

resin decreases water sorption and solubility significantlycompared to pure PMMA Torres et al (2011) concludedthat PMMA-TiO

2-Fe2O3nanocomposites had lower sorption

and porosity values compared to pure PMMA but similarsolubility levels However the solubility levels were originallylow which is important to prevent the adverse effects on oralstructures or polymer functions [41] Also as thematerial getsmore homogenous it becomes less soluble with lower watersorption levels [29]

Therefore the addition of TiO2NP fills the microvoids

and polymer interstitial spaces decreasing the ability ofcomposite material to absorb water In addition to thatTiO2NP are insoluble in water and these particles partly

replace the hydrophilicmatrix which decreases water uptakeThe use of silane-coupling agent in silanization process ofTiO2NP could lead to a reduction in the amount of water that

reaches the inner layers of polymer matrix [18]

146 Thermal Properties The addition of 3 TiO2NP to

PMMA had no effect on thermal conductivity [25]The glasstransition temperature (Tg) test is done to understand thethermal stability and determine the temperature at whichthe material starts to degrade As the percentage of TiO

2NP

increases the Tg of nanocomposite increases linearly up to75wt TiO

2 Pure PMMA is stable up to 134∘C (1 weight

loss) while PMMA2wtTiO2and PMMA5wtTiO

2are

stable up to 154∘C and 180∘C respectively Tg was improvedby 15ndash34 with 2ndash5 addition of TiO

2NP respectively

However further addition of TiO2NP caused a decrease in

thermal stability [33] Another study by Safi (2014) reportedthe positive effect of TiO

2NP addition on the Tg temperature

of acrylic resin [51] In a recent study [43] authors evaluatedthe effect of adding 1 2 and 3 TiO

2NP to PMMA on

thermal behavior and found a slight effect on Tg degradationtemperature and rate

Chatterjee (2010) in another study reported that theaddition of 5wt TiO

2NP caused a 23 increase in Tg and

this improvement reached only 3 when the amount ofTiO2NPwas increased to 15 [9] Also pure PMMA showed

5 weight loss at 217∘C while a higher temperature (310∘C)was needed to create the same effect in the PMMA5wtTiO

2

[9] Recently Totu et al (2018) [14] confirmed the increasein decomposition temperature for PMMATiO

2NP compos-

ite suggesting an improved thermal stability This may beexplained by the reduced intercrystalline distance interac-tion and bond formation betweennanoparticles and polymerchains or the absorption of some energy by the titania par-ticles increasing the thermal stability Final decompositionof the PMMATiO

2NP composite happened at temperatures

620-700∘C with decreasing pattern of the total mass loss asthe amount of nanoparticles increased

The thermal stability of TiO2NP added to PMMA inhibits

the degradation of the resin and improves the thermalstability of the composite material [33] Another explanationfor thermal stability is the migration of TiO

2NP with low

surface energy to the surface of the PMMA resin to forma heat resistant layer [9] The decrease in thermal stabilitywith higher amount of nanofiller may be attributed to theagglomeration of filler particles rather than forming a filler-to-matrix interaction This agglomeration reduces the effectof heat retardation associated with TiO

2NP [33] TiO

2NP

crystalline phase has free electrons that can be associatedwithsurface reactions Oxygen that diffused in the nanocompositesamples was absorbed on the surface of TiO

2NP Hence

diffused oxygen amount in the PMMAmatrix was lower thanin pure PMMA which led to the slower thermooxidativedegradation of the PMMAmatrix [9 33]

It is knows that PMMA shrinks upon polymerizationcausing dimensional changes in the final product Dimen-sional stability is also affected by coefficient of thermalexpansion The result of a study by Hashem et al (2017)[22]showed that pure PMMA and PMMA3TiO

2started to

disintegrate and lose weight at 200∘C with 90 weightloss happening at 400∘C for both materials suggesting nosignificant effect of TiO

2NPon themelting temperature of the

composite material This might be explained by the minimalamount of filler addition or the presence of large number ofdecomposition sites within the material [22]

147 Viscoelastic Behavior Little work has been doneon the effects of TiO

2NP on the viscoelastic behavior

(creep-recovery and relaxation) behavior of PMMA matrixRecently in a study by Alrahlah done to investigate vis-coelastic properties of TiO

2NP-modified PMMA denture

base composite it was found that the creep-recovery andrelaxation behaviors of PMMA were significantly improveddue to the addition of TiO

2NPAlso the improvement further

increased as the concentration of the nanofiller changed from1 to 3This improvement in the behavior indicates the roleof the nanoparticles in increasing the stiffness of the PMMAmatrix owing to the reduction in its molecular mobility andfree volume [43]

148 Electrical Behavior It is imperative to avoid prolongedcontact between oral mucosa and materials with high elec-trical conductivity Metallic particles present in restorativematerials my produce a galvanic effect in the highly con-ductive oral environment causing oral discomfort changesin cell proliferation and immune markers [27 54] Totu andcolleagues (2018) [55] studied the effect of adding differentpercentages of TiO

2NP (0 (control) 02 04 06

10 20 25 and 5) to PMMA used for 3D printingon the electrical properties of the resulting nanocompositeThey reported a decrease in material resistance with theadditions of ge1 TiO

2NP Also an increase in electrical con-

ductivity was noted with the addition of 5 TiO2NP How-

ever the composite material still maintained its insulatingproperty

International Journal of Biomaterials 7

2 Overall Performanceand Clinical Significance

It is well understood that advancements in biomaterialscience affect the progression of technologies in any fieldincluding dental prostheses The introduction of nanomate-rials had significantly changed the clinical and technolog-ical aspects of dentistry In this paper the latest researchprogress on the applications of TiO

2NP in prosthodontics

was reviewed It clearly shows varying responses of phys-ical and mechanical properties of the modified materialswhere a number of properties improved others deterio-rated and few did not change Their level of effectivenessas shown in the literature is diverse being more or lesseffective than pure materials Therefore to attain removableprostheses with improved properties and acceptable clinicalperformance the material of manufacture (acrylic resin)can be enhanced by adding proper percentage of nanofillerinitial surface treatment of the nanoparticles and appro-priate selection of addition method Authors hope that thisreview article would provide some valuable elicitation forfuture scientific and technological innovations in the relatedfield

Based on this review TiO2NPwere found to be enhancers

in some aspects modifiers in some and insignificant in oth-ers The effect depends mainly on NP size addition methodsurface treatment and loading percentage Although the sizeof NP ranged between 5 nm and 350 nm the results of thestudies were not justified based on the nanofiller size anda clear link between size and effect was not established Forthat further investigations to relate the resulting propertiesto nanoparticle size are required

Variations in the results were mainly related to fillermode of addition The addition of nanoparticles to acrylicmonomer was considered more effective owing to betterdispersion of NP within the monomer In this method thedominant improvement was noticed in mechanical prop-erties while physical properties were slightly affected It isworth noting that with this technique the polymer monomerratio may be affected Therefore mixing the nanofillerwith acrylic powder has been suggested and studied Tillnow no study can be found that compares between theeffects of different modes of addition (nanofillers additionto powder or monomer) Based on this review furtherinvestigations of the above-mentioned point are necessaryas well as the proper way to establish the proportion ofpolymermonomer ratio for each method hence nanofilleraddition interferes with the manufacturersquos recommendedratios

The percentage of addition also plays a role in resultingproperties While the range of addition was very broad(05ndash30wt) low percentages resulted in improved prop-erties compared to higher percentages Simple addition of1ndash2wt ratios exhibited improved properties while increas-ing the filler content more than 5wt significantly weakenedthe final nanocomposites In fact the bonding betweenTiO2NP and resin matrix is a critical factor to achieve the

desired properties of nanocomposite As showed in Table 1the treatment of NPwith saline coupling agents improved the

properties in comparison to untreated particles ThereforeNP surface treatment is recommended

According to Table 1 inconsistencies in prepared spec-imen sizes for the same test were seen which may havecontributed to variations in the results between studiesexperimenting with the same filler percentage This reflectsa major error in the methodologies of the studies where thetest should have been done according to standardized spec-imensrsquo dimensions and testing procedures Testing shouldfollow an internationally accepted standardization proto-col like the ADA specifications for denture base polymersto make it possible to compare results between differentstudies

Titanium nanoparticles remain under focus because ofthe antimicrobial efficacy against candida species despitetheir negative effect on a number of properties Incorporationof TiO

2NP into PMMA matrix proved to have antimicrobial

effects specifically on candida species [24] Not to be lost inthis discussion is the effect of TiO

2NP surface modification

on antimicrobial properties of the final product It was shownthat modification with noble metals such as (Ag Au Ptand Pd) on TiO

2NP surface enhanced the photocatalytic

ability of the nanoparticles and bactericidal activity thereafter[12]

Even with this number of studies on recently introducedTiO2NP into PMMA no clear evidence on the clinical

applicability of this nanocomposite has been demonstratedFurther investigations are required to interpret and confirmthe chemical structure changes in PMMATiO

2nanocom-

posite and also to determine the need from otherwise forsurface treatment as well as the proper percentage of additionthat will not affect the final product adversely

Research to improve upon existing nanomaterials is stillongoing with emphasis on efficiency Although the sciencebehind nanotechnology is intriguing the lack of long-termevidence addressing their clinical performance restricts theirwide clinical use Overall there is an essential requirement toinvestigate the durability of these PMMATiO

2composites in

different environmental conditions to extend the applicabilityof these hybrid materials

3 Conclusion

Based on the current review we could conclude thatthe addition of TiO

2NP to PMMA denture bases is still

questionable for working as a reinforcing material andrequires further investigations following the ADA specifica-tions These investigations must explore the chemical andstructural changes happening in the nanocomposite afterTiO2addition The improvements in properties mentioned

above were dominantly seen with lower concentrations ofTiO2and the increase in the amount of added nanopar-

ticles caused adverse effects on resulting PMMATiO2

compositeIn conclusion there is an essential need to investigate the

clinical performance and durability of these nanocompositesin different conditions simulating the oral environment toverify their applicability and provide an insight of possiblefuture researches in this field

8 International Journal of Biomaterials

Table1TiO2NPapplications

indentureb

asea

ndits

effecto

nthetestedprop

ertie

s

Authorsyear

Particlesiz

eAd

ditio

npercentage

Type

ofAc

rylic

Nanocom

positep

reparatio

nProp

ertie

stested

Specim

ensiz

eEff

ects

(IncreaseD

ecreaseUnchanged)

Chatterje

e2010

[9]

5nm

0-15w

tPM

MAfro

mScientificP

olym

erProd

ucts(O

ntario

NY)

(i)MeasuredTiO2NPmixed

with

PMMAfor5

-10min

(ii)D

ACAtwin-screw

extractio

nprocessa

t190∘C

and100rpm

(iii)Ac

rylic

mixed

for6

-7min

andextrud

ed5tim

es

(i)Tensile

mod

ulus

(ii)D

imensio

nal

stability

(iii)Glasstransition

temperature(T

g)

(iv)U

Vabsorptio

n

10x6x03m

m

5mg

(i)Im

provem

entintensile

mod

ulus

(ii)Increased

thermalsta

bility

(iii)IncreasedT g

(iv)Improvem

entinUV

absorptio

n997888rarr

maxim

umat2

TiO2NP

Chatterje

e2010

[10]

5nm

0 20

50 75

100

150

300

PMMAfro

mScientificP

olym

erProd

ucts(O

ntario

NY)

(i)MeasuredTiO2NPmixed

with

PMMAfor5

-10min

(ii)D

ACAtwin-screw

extractio

nprocessa

t190∘C

and100rpm

(iii)Ac

rylic

mixed

for6

-7min

andextrud

ed5tim

es

(i)Glasstransition

temperature(T

g)

(ii)Th

ermalsta

bility

(iii)Decom

position

temperature

10x6x03m

m

(i)T g

increasedlin

early

upto

75TiO2NP

(ii)Th

ermalsta

bilityincreased

(2-15

TiO2NP)

(iii)Decom

position

temperaturesincreased

with

filler

contentu

pto

10TiO2NP

Aneho

suretal

2012

[11]

31nm

ldquoAnataseph

aserdquo

30

Inadditio

nto

surfa

cecoating

DPI

heatcure

acrylic

resin

(In

dia)

(i)Visib

lelig

htactiv

ated

TiO2NPwe

remixed

with

methylm

ethacrylate

mon

omer

(i)Microbial

inhibitory

effect

againstSA

ureus

5x5x2mm

(i)3w

of

TiO2show

santim

icrobialactiv

ityagainstS

Au

reus

Sodagare

tal2013

[12]

21nm

ldquoAnatase

phaserdquo

0 05 10

SelectaP

lus

(self-c

urea

crylic

resin

)

(i)TiO2NPwe

readdedto

acrylic

mon

omer

(i)Flexuralstr

ength

50x10

x33m

m(i)

Flexuralstr

engthdecreasedas

thefi

llerc

ontent

increased

(i)Flexuralmod

ulus

(i)Nochange

inflexu

ral

mod

ulus

Ham

ouda

and

Beyari

2014

[13]

21nm

50

Con

ventionalh

eat

cure

acrylic

resin

(AcrostonWHN

England)

andhigh

impact(M

etrocryl

HiMetrodent

LTDE

ngland

)

(i)TiO2NPwe

remixed

thorou

ghlywith

acrylic

powd

erby

hand

(ii)F

lexu

ral

strength

(iii)To

ughn

ess

65x10

x25mm

(ii)F

lexu

ralstre

ngth

and

toug

hnessd

ecreased

(iv)M

onom

errelease

(iii)Nodifferenceb

etwe

encontroland

TiO2reinforced

regardingmon

omer

release

International Journal of Biomaterials 9

Table1Con

tinued

Authorsyear

Particlesiz

eAd

ditio

npercentage

Type

ofAc

rylic

Nanocom

positep

reparatio

nProp

ertie

stested

Specim

ensiz

eEff

ects

(IncreaseD

ecreaseUnchanged)

Nazirk

aretal

2014

[14]

7nm

ldquoAnatase

phaserdquo

0 05 10

DPI

heatcure

acrylic

resin

(i)TiO2NPaddedto

acrylic

mon

omer

(i)Flexuralstr

ength

65x10

x33mm

(i)Flexuralstr

engthdecreasedas

theT

iO2am

ount

increased

Shirk

avandand

Moslehifard2014

[15]

lt25

nm(averagesim204

nm)

ldquoAnataseand

Rutilep

hasesrdquo

0 05 10

20

Heatcurea

crylic

resin

from

Ivoclar

Vivadent

(i)TiO2NPwe

remixed

with

thea

crylicresin

polymer

inan

amalgamator

for2

0min

(i)Tensile

strength

60x12

x4mm

(i)Tensile

strengthandelastic

mod

ulus

improved

with

1TiO2NP

(ii)0

5and2

TiO2we

reno

tsig

nificantly

different

from

each

othero

rcon

trol

Harinietal2014

[16]

0 10

20

50

Clearh

eatcure

acrylic

resin

(i)Nanop

artic

lesw

ere

incorporated

into

mon

omer

byultrason

icdispersio

n(i)

Flexuralstr

ength

65x10

x3mm

(i)Flexuralstr

engthim

proved

with

TiO2additio

nsig

nificant

differencen

oticed

with

5

Safi2014

[17]

50

Heatcured

enture

base

acrylic

(Sup

eracrylplus

Czecho

slovakia)

(i)Nanop

artic

lesa

dded

tomon

omer

andsonically

dispersed

(i)Coefficientof

thermalexpansion

(ii)M

odulus

(iii)Glasstransition

15x6mm

Cylin

ders

65x10

x25mm

Powd

erform

(10g)

(i)Decreaseincoeffi

cientof

thermalexpansion

(ii)D

ecreased

inmod

ulus

ofelastic

ity

(iii)IncreasedT g

Alwanand

Alameer2015

[18]

lt50

nmsiz

e0 30

(i)Silanizedwith

TMSP

M

Heatcurea

crylic

resin

(i)SilanizedTiO2NPwe

readdedto

mon

omer

and

sonicated

(i)Im

pactstr

ength

(ii)T

ransverse

strength

(iii)Hardn

ess

(iv)S

urface

roug

hness

(v)W

atersorptio

nandsolubility

80x10

x4mm

65x10x25m

m

50x05m

mdisc

(i)Increased

(ii)Increased

(iii)Increased

(iv)Increased

(v)D

ecreased

10 International Journal of Biomaterials

Table1Con

tinued

Authorsyear

Particlesiz

eAd

ditio

npercentage

Type

ofAc

rylic

Nanocom

positep

reparatio

nProp

ertie

stested

Specim

ensiz

eEff

ects

(IncreaseD

ecreaseUnchanged)

Ahm

edetal2016

[19]

46nm

0 10

50

Con

ventionalh

eat

cure

acrylic

resin

(ImplacrylVe

rtex)

andhigh

impact

heatcureacrylic

resin

(Vertex-Dental

Netherla

nds)

(i)TiO2NPwe

readdedinto

acrylic

resin

(i)Flexuralstr

ength

(ii)Impactstr

ength

(iii)Hardn

ess

50x10

x3mm

60x6x4mm

25x10

x3mm

(i)Decreased

with

TiO2

additio

n

(ii)Increased

onlyfor

conventio

nalacrylicresin

mod

ified

by1

(iii)Increasedwith

5additio

nTiO2NPforb

othtypeso

facrylic

Sodagare

tal2016

[20]

21nm

05 10

SelectaP

lus

(self-c

urea

crylic

resin

)

(i)Nanop

artic

lesw

erea

dded

toacrylic

mon

omer

and

stirred

(i)Antim

icrobial

prop

ertie

s20

x20

x1m

m

(i)TiO2redu

cedmicrobial

grow

thatbo

thconcentrations

at90

min

underU

VAexpo

sure

(ii)A

ntim

icrobialactiv

ityof

TiO2istim

edependent

Ahm

edetal2017

[21]

lt25

nm0 05 10

Heatcurea

crylic

resin

from

Dentsp

lyInternationalInc

(ChicagoIL

USA

)

(i)TiO2NPwe

readdedto

acrylic

polymer

andmixed

usingam

algam

capsule

(i)Flexuralstr

ength

(ii)F

racture

toug

hness

(iii)Hardn

ess

65x10

x25mm

65x10

x25mm

30x10

x25mm

(i)Increasedwith

both

filler

percentages

(ii)N

oeffecto

nfracture

toug

hnesso

fbothfiller

percentages

(iii)Increasedwith

1filler

Hashem

etal2

017

[22]

90nm

0 10

20 30

Self-cureacrylic

resin

from

Eco-crylcold

Protechn

o(Spain)

(i)TiO2NPwe

remixed

with

them

onom

er

(i)Flexuralmod

ulus

andflexu

ral

strength

(ii)H

ardn

ess

(iii)Surfa

cewe

tting

30x8x1m

m

50x1m

mdiscs

(i)Increasedlin

early

(ii)Increased

(iii)Re

ducedwith

1filler

contentand

increasedwith

high

erpercentages

(iv)T

gdecreasedwith

TiO2

additio

n

Ghahrem

anietal

2017

[23]

20-30nm

ldquoAnatase

phaserdquo

0 10

SRTriplexHot

heatcureacrylic

resin

(Ivoclar

Vivadent

Inc

Schaan

Liechtenste

in)

(i)TiO2NPwe

remixed

with

acrylic

resin

powd

erin

anultrason

icmixer

(i)Tensile

strength

(ii)Impactstr

ength

60x12

x39mm

75x10

x10

mm

(i)Increased

(ii)Increased

International Journal of Biomaterials 11Ta

ble1Con

tinued

Authorsyear

Particlesiz

eAd

ditio

npercentage

Type

ofAc

rylic

Nanocom

positep

reparatio

nProp

ertie

stested

Specim

ensiz

eEff

ects

(IncreaseD

ecreaseUnchanged)

Totu

etal2017

[24]

65-170

nm

0 02

04 1 25

PMMA+P

EMAfor

3Dprintin

g(eDent

100En

visio

nTec

GmbH

Gladb

eck

Germany)

(i)Nanop

artic

lesw

erea

dded

into

PMMAsolutio

nwith

continuo

usstirringand

ultrason

icmixingfor1

hour

(i)Antim

icrobial

effect(Ca

ndida

scotti)

(ii)C

omplete

denture

manufacturin

gusin

gste

reolith

ograph

y

(i)041

and25

inhibited

cand

idagrow

th

(ii)P

MMA04TiO2compo

site

successfu

llyused

ford

enture

fabrication

Aziz2018

[25]

30nm

0 30

Highim

pactheat

cure

acrylic

resin

(Vertex-Dental

Netherla

nds)-

(i)TiO2NPwe

redispersedin

mon

omer

andsonicatedat

120W

and60

KHzfor

3minutes

(i)Im

pactstr

ength

(ii)C

olor

stability

(iii)Th

ermal

cond

uctiv

ity

80x10

x4mm

35x15

x05mm

40x25mm

(i)Increased

(ii)Increased

colorstabilityfor

testgrou

ps

(iii)Noeffect

Alra

hlah

etal

2018

[26]

80-100

nm

0 1 2 3

Heatcurea

crylic

resin

(Lucito

ne550Dentsp

lyInt

IncPaU

SA)

(i)Hardn

essa

ndmod

ulus

(ii)T

gdegradation

temperatureand

rate

(iii)Cr

eep-recovery

andrelaxatio

nbehavior

(iv)A

ntibacteria

ladhesio

n

50x10

mm

discs

cutindifferent

sizes

ford

ifferent

tests

7mg

5x10

mm

(i)Increased

(ii)S

light

increase

with

2nano

-fillerc

ontent

(iii)Im

provem

entinbehavior

(iv)D

ecreaseinbacterial

attachmentcon

tent

Karcietal2018

[27]

13nm

0 1 3 5

(i)Au

to-polyeriz

ed(H

eraeus

Kulze

rNew

bury

Berkshire

UK)

(ii)

Heat-p

olym

erized

Heraeus

Kulze

rNew

bury

Berkshire

UK

(iii)Microwave-

polymerized

(GC

DentalTo

kyo

Japan)

(i)TiO2NPwe

remixed

with

acrylic

resin

powd

erusing

ballmillingat40

0rpm

for2

hours

(i)Flexuralstr

ength

65x10

x3mm

(i)Increasedforh

eat-and

auto-polym

erized

acrylic

at1

(ii)D

ecreased

fora

lltypeso

facrylic

at5

12 International Journal of Biomaterials

Table1Con

tinued

Authorsyear

Particlesiz

eAd

ditio

npercentage

Type

ofAc

rylic

Nanocom

positep

reparatio

nProp

ertie

stested

Specim

ensiz

eEff

ects

(IncreaseD

ecreaseUnchanged)

Totu

etalTo

tuet

al2

017[28]

ldquoAnatase

phaserdquo

0 02

04

06 10

25

(i)PM

MA-

MA

(ii)P

MMA-

MMA-

BPO

(iii)3D

printed

PMMA(eD

Envisio

nTec

GmbH

Gladb

eck

Germany)

(i)TiO2mod

ified

bymethacrylicacid

then

manually

mixed

with

PMMAmixture

(i)Th

ermalsta

bility

(ii)T

g

Stereolitho

graphic

dentures

(i)Increased(im

proved)

(ii)Increased

Totu

etal2018

[29]

ldquoAnatase

phaserdquo

0 02

04

06 10

20 25 50

PMMAfor3

Dprintin

g(eDent

100En

visio

nTec

GmbH

Gladb

eck

Germany)

(i)Re

sistance

(ii)E

lectric

alcond

uctiv

ity

(iii)Dielectric

constant

(i)Decreased

with

1020

25

and5

(ii)Increased

butm

aterialstill

maintainedinsulatin

gprop

ertie

s

(iii)Increasedwith

5

International Journal of Biomaterials 13

Conflicts of Interest

The authors declare that they have no conflicts of interest

References

[1] R L Sakaguchi and J M Powers Craigrsquos Restorative DentalMaterials Elsevier Health Sciences Philadelphia PA USA pp163-176 2012

[2] N Murakami N Wakabayashi R Matsushima A Kishidaand Y Igarashi ldquoEffect of high-pressure polymerization onmechanical properties of PMMA denture base resinrdquo Journalof the Mechanical Behavior of Biomedical Materials vol 20 pp98ndash104 2013

[3] R Adhikari and G H Michler ldquoPolymer nanocompositescharacterization by microscopyrdquo Polymer Reviews vol 49 no3 pp 141ndash180 2009

[4] A Navidfar T Azdast and A Karimzad Ghavidel ldquoInfluenceof processing condition and carbon nanotube on mechani-cal properties of injection molded multi-walled carbon nan-otubepoly(methyl methacrylate) nanocompositesrdquo Journal ofApplied Polymer Science vol 133 no 31 Article ID 43738 pp1ndash9 2016

[5] P Chaijareenont H Takahashi N Nishiyama and M Ark-sornnukit ldquoEffect of different amounts of 3-methacryloxypro-pyltrimethoxysilane on the flexural properties and wear resis-tance of alumina reinforced PMMArdquo Dental Materials vol 31no 4 pp 623ndash628 2012

[6] J Jordan K I Jacob R TannenbaumMA Sharaf and I JasiukldquoExperimental trends in polymer nanocompositesmdasha reviewrdquoMaterials Science and Engineering A vol 393 no 1-2 pp 1ndash112005

[7] MMGad SM Fouda F A Al-Harbi RNapankangas andARaustia ldquoPMMAdenture base material enhancement A reviewof fiber filler and nanofiller additionrdquo International Journal ofNanomedicine vol 12 pp 3801ndash3812 2017

[8] F Li S Zhou B You and L Wu ldquoKinetic study onthe UV-induced photopolymerization of epoxy acrylateTiO2nanocomposites by FTIR spectroscopyrdquo Journal of AppliedPolymer Science vol 99 no 6 pp 3281ndash3287 2006

[9] A Chatterjee ldquoProperties improvement of PMMA using nanoTiO2rdquo Journal of Applied Polymer Science vol 118 no 5 pp2890ndash2897 2010

[10] P Harini K Mohamed and T V Padmanabhan ldquoEffect ofTitanium dioxide nanoparticles on the flexural strength ofpolymethylmethacrylate An in vitro studyrdquo Indian Journal ofDental Research vol 25 no 4 pp 459ndash463 2014

[11] G Venkatesh Anehosur R D Kulkarni M G Naik et alldquoSynthesis and Determination of Antimicrobial Activity ofVisible Light Activated TiO2 Nanoparticles with PolymethylMethacrylate Denture Base Resin Against StaphylococcusAureusrdquo Journal of Gerontology ampGeriatric Research vol 01 no01 pp 103ndash111 2012

[12] A Sodagar A Bahador S Khalil A Saffar Shahroudi and MZaman Kassaee ldquoThe effect of TiO

2and SiO

2nanoparticles on

flexural strength of poly (methyl methacrylate) acrylic resinsrdquoJournal of Prosthodontic Research vol 57 no 1 pp 15ndash19 2013

[13] I M Hamouda and M M Beyari ldquoAddition of glass fibers andtitanium dioxide nanoparticles to the acrylic resin denture basematerial comparative study with the conventional and highimpact typesrdquo Oral Health and Dental Management vol 13 pp107ndash112 2014

[14] E E Totu C M Cristache E Voicila et al ldquoOn physicaland chemical characteristics of Poly(methylmethacrylate) na-nocomposites for dental applications IrdquoMateriale Plastice vol54 no 4 pp 666ndash672 2017

[15] S Shirkavand and EMoslehifard ldquoEffect of TiO2 nanoparticleson tensile strength of dental acrylic resinsrdquo Journal of DentalResearch Dental Clinics Dental Prospects vol 8 no 4 pp 197ndash203 2014

[16] M Karci N Demir and S Yazman ldquoEvaluation of FlexuralStrength of Different Denture Base Materials Reinforced withDifferent Nanoparticlesrdquo Journal of Prosthodontics 2018

[17] O Gurbuz F Unalan and I Dikbas ldquoComparison of thetransverse strength of six acrylic denture resinsrdquo OhdmbscMagazines vol 9 pp 21ndash24 2010

[18] S A Alwan and S S Alameer ldquoThe Effect of the Addition ofSilanized Nano Titania Fillers on Some Physical and Mechan-ical Properties of Heat Cured Acrylic Denture Base MaterialsrdquoJournal of Baghdad College of Dentistry vol 27 no 1 pp 86ndash912015

[19] M Ashour Ahmed M El-Shennawy Y M Althomali andA A Omar ldquoEffect of Titanium Dioxide Nano Particles In-corporation on Mechanical and Physical Properties on TwoDifferent Types of Acrylic Resin Denture Baserdquo World Journalof Nanoscience and Engineering vol 06 no 03 pp 111ndash119 2016

[20] A Sodagar S Khalil M Z Kassaee A S Shahroudi B Pourak-bari and A Bahador ldquoAntimicrobial properties of poly (methylmethacrylate) acrylic resins incorporated with silicon dioxideand titanium dioxide nanoparticles on cariogenic bacteriardquoJournal of Orthodontic Science vol 5 no 1 pp 7ndash13 2016

[21] M A Ahmed A A Omar M El-Shennawy M I Ebrahimand Y M Althomali ldquoInfluence of addition of different types ofnano-fillers on the microstructure and mechanical propertiesof PMMA based denture resinrdquo Kasmera Journal vol 45 pp48ndash59 2017

[22] MHashemM F Al Rez H Fouad et al ldquoInfluence of titaniumoxide nanoparticles on the physical and thermomechanicalbehavior of poly methyl methacrylate (pmma) A denture baseresinrdquo Science of Advanced Materials vol 9 no 6 pp 938ndash9442017

[23] L Ghahremani S Shirkavand F Akbari and N SabzikarildquoTensile strength and impact strength of color modified acrylicresin reinforcedwith titaniumdioxide nanoparticlesrdquo Journal ofClinical and Experimental Dentistry vol 9 no 5 pp e661ndashe6652017

[24] E E Totu A C Nechifor G Nechifor H Y Aboul-Eneinand C M Cristache ldquoPoly(methyl methacrylate) with TiO2nanoparticles inclusion for stereolitographic complete denturemanufacturing minus the fututre in dental care for elderly edentu-lous patientsrdquo Journal of Dentistry vol 59 pp 68ndash77 2017

[25] H K Aziz ldquoTiO-Nanofillers Effects on Some Properties ofHighly- Impact Resin Using Different Processing TechniquesrdquoThe Open Dentistry Journal vol 12 no 1 pp 202ndash212 2018

[26] M Tsuji T Ueda K Sawaki M Kawaguchi and K SakuraildquoBiocompatibility of a titanium dioxide-coating method fordenture base acrylic resinrdquo Gerodontology vol 33 no 4 pp539ndash544 2016

[27] S PodzimekM Tomka P Sommerova Y Lyuya-Mi J Bartovaand J Prochazkova ldquoImmune markers in oral discomfortpatients before and after elimination of oral galvanismrdquo Neu-roendocrinology Letters vol 34 no 8 pp 802ndash808 2013

[28] S Kiat-amnuayM Beerbower JM Powers andRD ParavinaldquoInfluence of pigments and opacifiers on color stability of

14 International Journal of Biomaterials

siliconemaxillofacial elastomerrdquo Journal ofDentistry vol 37 no1 pp e45ndashe50 2009

[29] S H Tuna F Keyf H O Gumus and C Uzun ldquoThe evaluationof water sorptionsolubility of various acrylic resinsrdquo EuropeanJournal of Dental Education vol 2 pp 191ndash197 2008

[30] S M Khaled R Sui P A Charpentier and A S RizkallaldquoSynthesis of TiO

2-PMMA nanocomposite using methacrylic

acid as a coupling agentrdquo Langmuir vol 23 no 7 pp 3988ndash39952007

[31] L Reijnders ldquoThe release of TiO2 and SiO2 nanoparticles fromnanocompositesrdquo Polymer Degradation and Stability vol 94no 5 pp 873ndash876 2009

[32] G Nazirkar S Bhanushali S Singh B Pattanaik and N RajldquoEffect of Anatase Titanium Dioxide Nanoparticles on theFlexural Strength of Heat Cured Poly Methyl MethacrylateResins An In-Vitro Studyrdquo Journal of Indian ProsthodontistSociety vol 14 pp 144ndash149 2014

[33] A Chatterjee ldquoEffect of nanoTiO2addition on poly(methyl

methacrylate) an exciting nanocompositerdquo Journal of AppliedPolymer Science vol 116 no 6 pp 3396ndash3407 2010

[34] S Rashahmadi R Hasanzadeh and S Mosalman ldquoImprov-ing the Mechanical Properties of Poly Methyl MethacrylateNanocomposites for Dentistry Applications Reinforced withDifferent Nanoparticlesrdquo PolymermdashPlastics Technology andEngineering vol 56 no 16 pp 1730ndash1740 2017

[35] A H Yuwono B Liu J Xue et al ldquoControlling the crystallinityand nonlinear optical properties of transparent TiO

2-PMMA

nanohybridsrdquo Journal of Materials Chemistry vol 14 no 20 pp2978ndash2987 2004

[36] J K Pandey K RaghunathaReddy A P Kumar andR P SinghldquoAn overviewon the degradability of polymer nanocompositesrdquoPolymer Degradation and Stability vol 88 no 2 pp 234ndash2502005

[37] C Tao S Jianping J Weng L Ting and H Xiaozhu ldquoPrepara-tion and properties of PMMATiO2 nanocompositerdquoChemicalReaction Engineering andTechnology vol 23 pp 435ndash440 2007

[38] A H Yuwono J Xue J Wang et al ldquoTransparent nanohybridsof nanocrystalline TiO2 in PMMA with unique nonlinearoptical behaviorrdquo Journal of Materials Chemistry vol 13 no 6pp 1475ndash1479 2003

[39] R Alla K N Raghavendra R Vyas and A KonakanchildquoConventional and contemporary polymers for the fabricationof denture prosthesis Part I overview composition and proper-tiesrdquo International Journal of Applied Dental Sciences vol 1 noPart I pp 82ndash89 2015

[40] C C Trapalis P Keivanidis G Kordas et al ldquoTiO2(Fe3+)nanostructured thin films with antibacterial propertiesrdquo ThinSolid Films vol 433 no 1-2 pp 186ndash190 2003

[41] L S Acosta-Torres L M Lopez-Marın R E Nunez-Anita GHernandez-Padron and V M Castano ldquoBiocompatible Metal-Oxide Nanoparticles Nanotechnology Improvement of Con-ventional Prosthetic Acrylic Resinsrdquo Journal of Nanomaterialsvol 2011 Article ID 941561 8 pages 2011

[42] A Bahador S Khalil B Pourakbari et al ldquoPhotocatalyticEffects of Acrylic Resins Incorporated with Nano-titaniumDioxide on Planktonic and Biofilm Growth of Four CariogenicBacteriardquo Annual Research amp Review in Biology vol 4 no 17pp 2695ndash2708 2014

[43] A Alrahlah H Fouad M Hashem A Niazy and A AlBadahldquoTitanium Oxide (TiO2)Polymethylmethacrylate (PMMA)Denture Base Nanocomposites Mechanical Viscoelastic and

Antibacterial BehaviorrdquoMaterials vol 11 no 7 Article ID 1096pp 10961ndash109615 2018

[44] A Kubacka M Ferrer M L Cerrada et al ldquoBoostingTiO2-anatase antimicrobial activity Polymer-oxide thin filmsrdquoApplied Catalysis B Environmental vol 89 no 3-4 pp 441ndash4472009

[45] Y Cheng T Sakai R Moroi et al ldquoSelf-cleaning abilityof a photocatalyst-containing denture base materialrdquo DentalMaterials vol 27 no 2 pp 179ndash186 2008

[46] C M Bollen P Lambrechts and M Quirynen ldquoComparisonof surface roughness of oral hard materials to the thresholdsurface roughness for bacterial plaque retention a review of theliteraturerdquoDental Materials vol 13 no 4 pp 258ndash269 1997

[47] N Elshereksi M Ghazali A Muchtar and C Azhari ldquoEffectof nanobarium titanate addition on the surface characteristicsof denture base resinrdquo International Journal of Mechanical andProduction Engineering vol 5 pp 1ndash8 2017

[48] Y Xia Z Feimin H Xie and N Gu ldquoNanoparticles reinforcedresin based dental compositesrdquo Journal of Dentistry vol 36 pp450ndash455 2008

[49] S Mosalman S Rashahmadi and R Hasanzadeh ldquoThe effectof TiO2 nanoparticles on mechanical properties of poly methylmethacrylate nanocompositesrdquo International Journal of Engi-neering Transactions B Applications vol 30 no 5 pp 807ndash8132017

[50] Y Han S Kiat-amnuay J M Powers and Y Zhao ldquoEffectof nano-oxide concentration on the mechanical properties ofa maxillofacial silicone elastomerrdquo The Journal of ProstheticDentistry vol 100 no 6 pp 465ndash473 2008

[51] I N Safi ldquoEvaluation the effect of nanomdashfillers (TiO2 AL2O3

SiO2) addition on glass transition temperature E-moudulus

and coefficient of thermal expansion of acrylic denture basematerialrdquo Journal of Baghdad College of Dentistry vol 26 no1 pp 37ndash41 2014

[52] W Wang S Liao Y Zhu M Liu Q Zhao and Y Fu ldquoRecentApplications of Nanomaterials in Prosthodonticsrdquo Journal ofNanomaterials vol 2015 Article ID 408643 11 pages 2015

[53] L Sun R F Gibson F Gordaninejad and J Suhr ldquoEnergyabsorption capability of nanocomposites A reviewrdquoCompositesScience and Technology vol 69 no 14 pp 2392ndash2409 2009

[54] S Podzimek K Hana M Miksovsky et al ldquoThe Influence ofgalvanic currents and voltage on the proliferation activity oflymphocytes and expression of cell surface moleculesrdquo FoliaBiologica vol 54 no 5 pp 146ndash150 2008

[55] E E Totu E Voicila V Pistritu G Nechifor and C MCristache ldquoEvaluation of electrical characteristics for PMMA-TiO2 nanocomposites used in dentistryrdquo Evista de Chimie vol69 no 1 pp 155ndash159 2018

CorrosionInternational Journal of

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Analytical ChemistryInternational Journal of

Hindawiwwwhindawicom Volume 2018

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Polymer ScienceInternational Journal of

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High Energy PhysicsAdvances in

Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawiwwwhindawicom

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Volume 2018

TribologyAdvances in

Hindawiwwwhindawicom Volume 2018

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ChemistryAdvances in

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Advances inPhysical Chemistry

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BioMed Research InternationalMaterials

Journal of

Hindawiwwwhindawicom Volume 2018

Na

nom

ate

ria

ls

Hindawiwwwhindawicom Volume 2018

Journal ofNanomaterials

Submit your manuscripts atwwwhindawicom

International Journal of Biomaterials 5

143 Mechanical Properties

(1) Flexural Properties During function oral appliancesincluding dentures are exposed to a magnitude of deformingstresses and any factor that increases the deformation of thedenture base may lead to fracture [17] One of the factorsthat may change the amount of denture deformation is theadditive into the PMMA resinThe effect of TiO2NP additionon flexural strength of PMMA is partially dependent onthe type of acrylics and the concentration of nanoparti-cles [19] In 2013 Sodagar et al investigated the effect ofadding 05 and 1 TiO2NP into PMMA and reporteda decrease in flexural strength PMMA containing 05wtshowed the lowest values It was concluded that there isan inverse relation between the concentration of the fillerand the flexural strength of reinforced PMMA [12] Hanet al (2008) reached the same conclusion and related theresults to agglomeration of particles within the matrix whichmakes them stress concentrations areas [50] Other studiesalso reported a reduction in flexural strength [13 19 32]and modulus of elasticity [51] with the addition of TiO

2NP

Hamouda et al (2014) found that TiO2NP caused a reduction

in flexural strength with no change in flexural modulus [13]In the same token Nazirkar et al in (2014) were exploringthe effect of adding TiO

2NP into heat cure acrylic resin on

antimicrobial properties and reported an adverse effect onflexural strength of the final product [32]

In contrast to previous studies superior flexural proper-ties were reported with different concentrations of TiO

2NP

added to PMMA than those of normal PMMA [10 18 21 52]This improvement may be attributed to the effect of silaniza-tion of TiO

2NP [18] or the good dispersion of fillers within

the matrix which improves modulus transverse strengthand ductility [18 52] Hashem et al (2017) found that with05ndash3wt TiO

2NP addition flexural strength and modulus

increased Moreover they suggested that reinforced PMMAcould offer superior chemical and mechanical propertiesmaking it a better option for dentures than pure PMMA resin[22] On the same way Rashahmadi et al (2017) found thatthe mere addition of 05 TiO

2NP improved the flexural

strength and Youngrsquos modulus by 4 Based on MCDMresults TiO

2NP addition to PMMA is an excellent option

for improving properties of PMMA for dental applicationsespecially in 2wt concentration [34] In a recent studyby Karci et al (2018) [16] different types (heat- auto- andmicrowave polymerized) of acrylic mixed with 1 3 and5 nanotio2 were used to test the flexural strength of theresulting composite That study came to a conclusion thatthe addition of 1 TiO

2NP to heat- and autopolymerized

acrylic could improve the flexural strength while it remainedunchanged with 3 TiO

2NP and decreased with 5 for all

types of acrylicThiswas explained by the increase in agglom-eration of nanoparticles at higher addition percentages

In a study by Mosalman et al (2017) various percentagesof TiO

2NP (05 1 and 2wt ) were added to pure PMMA

and found that the flexural strength of all groups stayedunchanged Sampleswith 05wtTiO

2NP showed only 375

improvement in flexural strength compared to pure PMMAYoungrsquos modulus for all groups was improved with the

highest value seen in samples containing 2wt TiO2NP

[49]

(2) Impact Strength With regard to impact strength theaddition of TiO

2NP to heat cured acrylic resin resulted

in a positive effect compared to pure PMMA [18] Studieshave confirmed this finding with different concentrationsof TiO

2NP including 1 [19 23] 2wt[34 49] and 3wt

[25] The same finding was reported after the addition ofsilanized TiO

2NP [53] The detected increase in impact

strength was justified by good bonding between PMMAmatrix and TiO

2nanofillers These fillers reside in small

voids between polymer chains and result in slow segmentalmotion Also they provide large surface area due to theirsmall size which helps in energy dissipation [25] Otherssuggested that the nanofillers in the acrylic resin toleratemost of the applied load while the resin matrix helps instructural integrity and load distribution which eventuallyinhibits crack propagation [23]

(3) Tensile Strength Shirkavand and Moslehifard (2014)investigated the effect of 05wt 1wt and 2wt TiO

2NP

on tensile strength of PMMA base resins and found that thetensile strength of nanocomposite was the highest with 1wtTiO2NP and the improvement was 35 more compared to

pure PMMA However further increase in TiO2NP content

led to an adverse effect [15] due to clustering of TiO2NP

The fillers work as impurities and act as defects and stressconcentration centers [15 49] The same results were alsoreported by Ghaheremani et al (2017) [23] The increase intensile strength is probably attributed to the fact that follow-ing the incorporation of nanoparticles into acrylic powderthe applied load is mainly tolerated by these nanoparticles

Contrary to previous studies Chatterjee in 2010 foundthat nanocomposite with filler content as high as 5wt and15wt had a 59 and 95 increase in tensile modulusrespectively compared to that of pure PMMA [9] This wascaused by the strong adhesion between TiO

2NP and PMMA

The applied load is transferred through these interfacialsurfaces to the strongest material that is the nanoparticles [9]

144 Color Stability It is noteworthy that the reinforcingfiller material should ideally improve the mechanical proper-ties without causing an adverse reaction to the aesthetics [2541] TiO

2NP have whitish color therefore the appropriate

percentage of this additive that fulfills the aforementionedrequirement should be considered An objective evaluation ofthe color change is usually done using a spectrophotometerwhere the difference between light absorption between dif-ferent samples is calculated [28] Aziz in 2018 evaluated thecolor change after adding 3wt of TiO

2NP and found that

the amount of light absorbed increasedmaking the reinforcedspecimens more opaque compared to pure PMMA Thischange was due to the presence of TiO

2NP within the

matrix which absorbs more light than polymer matrix duehigh atomic number [25] Further studies are required todetermine the proper TiO

2NP percentage needed to attain

a PMMATiO2nanocomposite with superior properties and

acceptable aesthetics

6 International Journal of Biomaterials

145 Water Sorption Solubility and Porosity Conventionalacrylic resins have voids and porosities that allow watermolecules exchange which could be the leading cause forwater sorption and solubility [18]The nature of denture resinmaterial allows it to absorb water which acts as a plasticizerand affects the material dimensional stability and denturedurability [41]Thewatermolecules force themselves betweenpolymer chains move them apart create internal stressesand result in crack formation [29] As reported by Alwan andAlameer [18] the addition of TiO

2NP to heat cure acrylic

resin decreases water sorption and solubility significantlycompared to pure PMMA Torres et al (2011) concludedthat PMMA-TiO

2-Fe2O3nanocomposites had lower sorption

and porosity values compared to pure PMMA but similarsolubility levels However the solubility levels were originallylow which is important to prevent the adverse effects on oralstructures or polymer functions [41] Also as thematerial getsmore homogenous it becomes less soluble with lower watersorption levels [29]

Therefore the addition of TiO2NP fills the microvoids

and polymer interstitial spaces decreasing the ability ofcomposite material to absorb water In addition to thatTiO2NP are insoluble in water and these particles partly

replace the hydrophilicmatrix which decreases water uptakeThe use of silane-coupling agent in silanization process ofTiO2NP could lead to a reduction in the amount of water that

reaches the inner layers of polymer matrix [18]

146 Thermal Properties The addition of 3 TiO2NP to

PMMA had no effect on thermal conductivity [25]The glasstransition temperature (Tg) test is done to understand thethermal stability and determine the temperature at whichthe material starts to degrade As the percentage of TiO

2NP

increases the Tg of nanocomposite increases linearly up to75wt TiO

2 Pure PMMA is stable up to 134∘C (1 weight

loss) while PMMA2wtTiO2and PMMA5wtTiO

2are

stable up to 154∘C and 180∘C respectively Tg was improvedby 15ndash34 with 2ndash5 addition of TiO

2NP respectively

However further addition of TiO2NP caused a decrease in

thermal stability [33] Another study by Safi (2014) reportedthe positive effect of TiO

2NP addition on the Tg temperature

of acrylic resin [51] In a recent study [43] authors evaluatedthe effect of adding 1 2 and 3 TiO

2NP to PMMA on

thermal behavior and found a slight effect on Tg degradationtemperature and rate

Chatterjee (2010) in another study reported that theaddition of 5wt TiO

2NP caused a 23 increase in Tg and

this improvement reached only 3 when the amount ofTiO2NPwas increased to 15 [9] Also pure PMMA showed

5 weight loss at 217∘C while a higher temperature (310∘C)was needed to create the same effect in the PMMA5wtTiO

2

[9] Recently Totu et al (2018) [14] confirmed the increasein decomposition temperature for PMMATiO

2NP compos-

ite suggesting an improved thermal stability This may beexplained by the reduced intercrystalline distance interac-tion and bond formation betweennanoparticles and polymerchains or the absorption of some energy by the titania par-ticles increasing the thermal stability Final decompositionof the PMMATiO

2NP composite happened at temperatures

620-700∘C with decreasing pattern of the total mass loss asthe amount of nanoparticles increased

The thermal stability of TiO2NP added to PMMA inhibits

the degradation of the resin and improves the thermalstability of the composite material [33] Another explanationfor thermal stability is the migration of TiO

2NP with low

surface energy to the surface of the PMMA resin to forma heat resistant layer [9] The decrease in thermal stabilitywith higher amount of nanofiller may be attributed to theagglomeration of filler particles rather than forming a filler-to-matrix interaction This agglomeration reduces the effectof heat retardation associated with TiO

2NP [33] TiO

2NP

crystalline phase has free electrons that can be associatedwithsurface reactions Oxygen that diffused in the nanocompositesamples was absorbed on the surface of TiO

2NP Hence

diffused oxygen amount in the PMMAmatrix was lower thanin pure PMMA which led to the slower thermooxidativedegradation of the PMMAmatrix [9 33]

It is knows that PMMA shrinks upon polymerizationcausing dimensional changes in the final product Dimen-sional stability is also affected by coefficient of thermalexpansion The result of a study by Hashem et al (2017)[22]showed that pure PMMA and PMMA3TiO

2started to

disintegrate and lose weight at 200∘C with 90 weightloss happening at 400∘C for both materials suggesting nosignificant effect of TiO

2NPon themelting temperature of the

composite material This might be explained by the minimalamount of filler addition or the presence of large number ofdecomposition sites within the material [22]

147 Viscoelastic Behavior Little work has been doneon the effects of TiO

2NP on the viscoelastic behavior

(creep-recovery and relaxation) behavior of PMMA matrixRecently in a study by Alrahlah done to investigate vis-coelastic properties of TiO

2NP-modified PMMA denture

base composite it was found that the creep-recovery andrelaxation behaviors of PMMA were significantly improveddue to the addition of TiO

2NPAlso the improvement further

increased as the concentration of the nanofiller changed from1 to 3This improvement in the behavior indicates the roleof the nanoparticles in increasing the stiffness of the PMMAmatrix owing to the reduction in its molecular mobility andfree volume [43]

148 Electrical Behavior It is imperative to avoid prolongedcontact between oral mucosa and materials with high elec-trical conductivity Metallic particles present in restorativematerials my produce a galvanic effect in the highly con-ductive oral environment causing oral discomfort changesin cell proliferation and immune markers [27 54] Totu andcolleagues (2018) [55] studied the effect of adding differentpercentages of TiO

2NP (0 (control) 02 04 06

10 20 25 and 5) to PMMA used for 3D printingon the electrical properties of the resulting nanocompositeThey reported a decrease in material resistance with theadditions of ge1 TiO

2NP Also an increase in electrical con-

ductivity was noted with the addition of 5 TiO2NP How-

ever the composite material still maintained its insulatingproperty

International Journal of Biomaterials 7

2 Overall Performanceand Clinical Significance

It is well understood that advancements in biomaterialscience affect the progression of technologies in any fieldincluding dental prostheses The introduction of nanomate-rials had significantly changed the clinical and technolog-ical aspects of dentistry In this paper the latest researchprogress on the applications of TiO

2NP in prosthodontics

was reviewed It clearly shows varying responses of phys-ical and mechanical properties of the modified materialswhere a number of properties improved others deterio-rated and few did not change Their level of effectivenessas shown in the literature is diverse being more or lesseffective than pure materials Therefore to attain removableprostheses with improved properties and acceptable clinicalperformance the material of manufacture (acrylic resin)can be enhanced by adding proper percentage of nanofillerinitial surface treatment of the nanoparticles and appro-priate selection of addition method Authors hope that thisreview article would provide some valuable elicitation forfuture scientific and technological innovations in the relatedfield

Based on this review TiO2NPwere found to be enhancers

in some aspects modifiers in some and insignificant in oth-ers The effect depends mainly on NP size addition methodsurface treatment and loading percentage Although the sizeof NP ranged between 5 nm and 350 nm the results of thestudies were not justified based on the nanofiller size anda clear link between size and effect was not established Forthat further investigations to relate the resulting propertiesto nanoparticle size are required

Variations in the results were mainly related to fillermode of addition The addition of nanoparticles to acrylicmonomer was considered more effective owing to betterdispersion of NP within the monomer In this method thedominant improvement was noticed in mechanical prop-erties while physical properties were slightly affected It isworth noting that with this technique the polymer monomerratio may be affected Therefore mixing the nanofillerwith acrylic powder has been suggested and studied Tillnow no study can be found that compares between theeffects of different modes of addition (nanofillers additionto powder or monomer) Based on this review furtherinvestigations of the above-mentioned point are necessaryas well as the proper way to establish the proportion ofpolymermonomer ratio for each method hence nanofilleraddition interferes with the manufacturersquos recommendedratios

The percentage of addition also plays a role in resultingproperties While the range of addition was very broad(05ndash30wt) low percentages resulted in improved prop-erties compared to higher percentages Simple addition of1ndash2wt ratios exhibited improved properties while increas-ing the filler content more than 5wt significantly weakenedthe final nanocomposites In fact the bonding betweenTiO2NP and resin matrix is a critical factor to achieve the

desired properties of nanocomposite As showed in Table 1the treatment of NPwith saline coupling agents improved the

properties in comparison to untreated particles ThereforeNP surface treatment is recommended

According to Table 1 inconsistencies in prepared spec-imen sizes for the same test were seen which may havecontributed to variations in the results between studiesexperimenting with the same filler percentage This reflectsa major error in the methodologies of the studies where thetest should have been done according to standardized spec-imensrsquo dimensions and testing procedures Testing shouldfollow an internationally accepted standardization proto-col like the ADA specifications for denture base polymersto make it possible to compare results between differentstudies

Titanium nanoparticles remain under focus because ofthe antimicrobial efficacy against candida species despitetheir negative effect on a number of properties Incorporationof TiO

2NP into PMMA matrix proved to have antimicrobial

effects specifically on candida species [24] Not to be lost inthis discussion is the effect of TiO

2NP surface modification

on antimicrobial properties of the final product It was shownthat modification with noble metals such as (Ag Au Ptand Pd) on TiO

2NP surface enhanced the photocatalytic

ability of the nanoparticles and bactericidal activity thereafter[12]

Even with this number of studies on recently introducedTiO2NP into PMMA no clear evidence on the clinical

applicability of this nanocomposite has been demonstratedFurther investigations are required to interpret and confirmthe chemical structure changes in PMMATiO

2nanocom-

posite and also to determine the need from otherwise forsurface treatment as well as the proper percentage of additionthat will not affect the final product adversely

Research to improve upon existing nanomaterials is stillongoing with emphasis on efficiency Although the sciencebehind nanotechnology is intriguing the lack of long-termevidence addressing their clinical performance restricts theirwide clinical use Overall there is an essential requirement toinvestigate the durability of these PMMATiO

2composites in

different environmental conditions to extend the applicabilityof these hybrid materials

3 Conclusion

Based on the current review we could conclude thatthe addition of TiO

2NP to PMMA denture bases is still

questionable for working as a reinforcing material andrequires further investigations following the ADA specifica-tions These investigations must explore the chemical andstructural changes happening in the nanocomposite afterTiO2addition The improvements in properties mentioned

above were dominantly seen with lower concentrations ofTiO2and the increase in the amount of added nanopar-

ticles caused adverse effects on resulting PMMATiO2

compositeIn conclusion there is an essential need to investigate the

clinical performance and durability of these nanocompositesin different conditions simulating the oral environment toverify their applicability and provide an insight of possiblefuture researches in this field

8 International Journal of Biomaterials

Table1TiO2NPapplications

indentureb

asea

ndits

effecto

nthetestedprop

ertie

s

Authorsyear

Particlesiz

eAd

ditio

npercentage

Type

ofAc

rylic

Nanocom

positep

reparatio

nProp

ertie

stested

Specim

ensiz

eEff

ects

(IncreaseD

ecreaseUnchanged)

Chatterje

e2010

[9]

5nm

0-15w

tPM

MAfro

mScientificP

olym

erProd

ucts(O

ntario

NY)

(i)MeasuredTiO2NPmixed

with

PMMAfor5

-10min

(ii)D

ACAtwin-screw

extractio

nprocessa

t190∘C

and100rpm

(iii)Ac

rylic

mixed

for6

-7min

andextrud

ed5tim

es

(i)Tensile

mod

ulus

(ii)D

imensio

nal

stability

(iii)Glasstransition

temperature(T

g)

(iv)U

Vabsorptio

n

10x6x03m

m

5mg

(i)Im

provem

entintensile

mod

ulus

(ii)Increased

thermalsta

bility

(iii)IncreasedT g

(iv)Improvem

entinUV

absorptio

n997888rarr

maxim

umat2

TiO2NP

Chatterje

e2010

[10]

5nm

0 20

50 75

100

150

300

PMMAfro

mScientificP

olym

erProd

ucts(O

ntario

NY)

(i)MeasuredTiO2NPmixed

with

PMMAfor5

-10min

(ii)D

ACAtwin-screw

extractio

nprocessa

t190∘C

and100rpm

(iii)Ac

rylic

mixed

for6

-7min

andextrud

ed5tim

es

(i)Glasstransition

temperature(T

g)

(ii)Th

ermalsta

bility

(iii)Decom

position

temperature

10x6x03m

m

(i)T g

increasedlin

early

upto

75TiO2NP

(ii)Th

ermalsta

bilityincreased

(2-15

TiO2NP)

(iii)Decom

position

temperaturesincreased

with

filler

contentu

pto

10TiO2NP

Aneho

suretal

2012

[11]

31nm

ldquoAnataseph

aserdquo

30

Inadditio

nto

surfa

cecoating

DPI

heatcure

acrylic

resin

(In

dia)

(i)Visib

lelig

htactiv

ated

TiO2NPwe

remixed

with

methylm

ethacrylate

mon

omer

(i)Microbial

inhibitory

effect

againstSA

ureus

5x5x2mm

(i)3w

of

TiO2show

santim

icrobialactiv

ityagainstS

Au

reus

Sodagare

tal2013

[12]

21nm

ldquoAnatase

phaserdquo

0 05 10

SelectaP

lus

(self-c

urea

crylic

resin

)

(i)TiO2NPwe

readdedto

acrylic

mon

omer

(i)Flexuralstr

ength

50x10

x33m

m(i)

Flexuralstr

engthdecreasedas

thefi

llerc

ontent

increased

(i)Flexuralmod

ulus

(i)Nochange

inflexu

ral

mod

ulus

Ham

ouda

and

Beyari

2014

[13]

21nm

50

Con

ventionalh

eat

cure

acrylic

resin

(AcrostonWHN

England)

andhigh

impact(M

etrocryl

HiMetrodent

LTDE

ngland

)

(i)TiO2NPwe

remixed

thorou

ghlywith

acrylic

powd

erby

hand

(ii)F

lexu

ral

strength

(iii)To

ughn

ess

65x10

x25mm

(ii)F

lexu

ralstre

ngth

and

toug

hnessd

ecreased

(iv)M

onom

errelease

(iii)Nodifferenceb

etwe

encontroland

TiO2reinforced

regardingmon

omer

release

International Journal of Biomaterials 9

Table1Con

tinued

Authorsyear

Particlesiz

eAd

ditio

npercentage

Type

ofAc

rylic

Nanocom

positep

reparatio

nProp

ertie

stested

Specim

ensiz

eEff

ects

(IncreaseD

ecreaseUnchanged)

Nazirk

aretal

2014

[14]

7nm

ldquoAnatase

phaserdquo

0 05 10

DPI

heatcure

acrylic

resin

(i)TiO2NPaddedto

acrylic

mon

omer

(i)Flexuralstr

ength

65x10

x33mm

(i)Flexuralstr

engthdecreasedas

theT

iO2am

ount

increased

Shirk

avandand

Moslehifard2014

[15]

lt25

nm(averagesim204

nm)

ldquoAnataseand

Rutilep

hasesrdquo

0 05 10

20

Heatcurea

crylic

resin

from

Ivoclar

Vivadent

(i)TiO2NPwe

remixed

with

thea

crylicresin

polymer

inan

amalgamator

for2

0min

(i)Tensile

strength

60x12

x4mm

(i)Tensile

strengthandelastic

mod

ulus

improved

with

1TiO2NP

(ii)0

5and2

TiO2we

reno

tsig

nificantly

different

from

each

othero

rcon

trol

Harinietal2014

[16]

0 10

20

50

Clearh

eatcure

acrylic

resin

(i)Nanop

artic

lesw

ere

incorporated

into

mon

omer

byultrason

icdispersio

n(i)

Flexuralstr

ength

65x10

x3mm

(i)Flexuralstr

engthim

proved

with

TiO2additio

nsig

nificant

differencen

oticed

with

5

Safi2014

[17]

50

Heatcured

enture

base

acrylic

(Sup

eracrylplus

Czecho

slovakia)

(i)Nanop

artic

lesa

dded

tomon

omer

andsonically

dispersed

(i)Coefficientof

thermalexpansion

(ii)M

odulus

(iii)Glasstransition

15x6mm

Cylin

ders

65x10

x25mm

Powd

erform

(10g)

(i)Decreaseincoeffi

cientof

thermalexpansion

(ii)D

ecreased

inmod

ulus

ofelastic

ity

(iii)IncreasedT g

Alwanand

Alameer2015

[18]

lt50

nmsiz

e0 30

(i)Silanizedwith

TMSP

M

Heatcurea

crylic

resin

(i)SilanizedTiO2NPwe

readdedto

mon

omer

and

sonicated

(i)Im

pactstr

ength

(ii)T

ransverse

strength

(iii)Hardn

ess

(iv)S

urface

roug

hness

(v)W

atersorptio

nandsolubility

80x10

x4mm

65x10x25m

m

50x05m

mdisc

(i)Increased

(ii)Increased

(iii)Increased

(iv)Increased

(v)D

ecreased

10 International Journal of Biomaterials

Table1Con

tinued

Authorsyear

Particlesiz

eAd

ditio

npercentage

Type

ofAc

rylic

Nanocom

positep

reparatio

nProp

ertie

stested

Specim

ensiz

eEff

ects

(IncreaseD

ecreaseUnchanged)

Ahm

edetal2016

[19]

46nm

0 10

50

Con

ventionalh

eat

cure

acrylic

resin

(ImplacrylVe

rtex)

andhigh

impact

heatcureacrylic

resin

(Vertex-Dental

Netherla

nds)

(i)TiO2NPwe

readdedinto

acrylic

resin

(i)Flexuralstr

ength

(ii)Impactstr

ength

(iii)Hardn

ess

50x10

x3mm

60x6x4mm

25x10

x3mm

(i)Decreased

with

TiO2

additio

n

(ii)Increased

onlyfor

conventio

nalacrylicresin

mod

ified

by1

(iii)Increasedwith

5additio

nTiO2NPforb

othtypeso

facrylic

Sodagare

tal2016

[20]

21nm

05 10

SelectaP

lus

(self-c

urea

crylic

resin

)

(i)Nanop

artic

lesw

erea

dded

toacrylic

mon

omer

and

stirred

(i)Antim

icrobial

prop

ertie

s20

x20

x1m

m

(i)TiO2redu

cedmicrobial

grow

thatbo

thconcentrations

at90

min

underU

VAexpo

sure

(ii)A

ntim

icrobialactiv

ityof

TiO2istim

edependent

Ahm

edetal2017

[21]

lt25

nm0 05 10

Heatcurea

crylic

resin

from

Dentsp

lyInternationalInc

(ChicagoIL

USA

)

(i)TiO2NPwe

readdedto

acrylic

polymer

andmixed

usingam

algam

capsule

(i)Flexuralstr

ength

(ii)F

racture

toug

hness

(iii)Hardn

ess

65x10

x25mm

65x10

x25mm

30x10

x25mm

(i)Increasedwith

both

filler

percentages

(ii)N

oeffecto

nfracture

toug

hnesso

fbothfiller

percentages

(iii)Increasedwith

1filler

Hashem

etal2

017

[22]

90nm

0 10

20 30

Self-cureacrylic

resin

from

Eco-crylcold

Protechn

o(Spain)

(i)TiO2NPwe

remixed

with

them

onom

er

(i)Flexuralmod

ulus

andflexu

ral

strength

(ii)H

ardn

ess

(iii)Surfa

cewe

tting

30x8x1m

m

50x1m

mdiscs

(i)Increasedlin

early

(ii)Increased

(iii)Re

ducedwith

1filler

contentand

increasedwith

high

erpercentages

(iv)T

gdecreasedwith

TiO2

additio

n

Ghahrem

anietal

2017

[23]

20-30nm

ldquoAnatase

phaserdquo

0 10

SRTriplexHot

heatcureacrylic

resin

(Ivoclar

Vivadent

Inc

Schaan

Liechtenste

in)

(i)TiO2NPwe

remixed

with

acrylic

resin

powd

erin

anultrason

icmixer

(i)Tensile

strength

(ii)Impactstr

ength

60x12

x39mm

75x10

x10

mm

(i)Increased

(ii)Increased

International Journal of Biomaterials 11Ta

ble1Con

tinued

Authorsyear

Particlesiz

eAd

ditio

npercentage

Type

ofAc

rylic

Nanocom

positep

reparatio

nProp

ertie

stested

Specim

ensiz

eEff

ects

(IncreaseD

ecreaseUnchanged)

Totu

etal2017

[24]

65-170

nm

0 02

04 1 25

PMMA+P

EMAfor

3Dprintin

g(eDent

100En

visio

nTec

GmbH

Gladb

eck

Germany)

(i)Nanop

artic

lesw

erea

dded

into

PMMAsolutio

nwith

continuo

usstirringand

ultrason

icmixingfor1

hour

(i)Antim

icrobial

effect(Ca

ndida

scotti)

(ii)C

omplete

denture

manufacturin

gusin

gste

reolith

ograph

y

(i)041

and25

inhibited

cand

idagrow

th

(ii)P

MMA04TiO2compo

site

successfu

llyused

ford

enture

fabrication

Aziz2018

[25]

30nm

0 30

Highim

pactheat

cure

acrylic

resin

(Vertex-Dental

Netherla

nds)-

(i)TiO2NPwe

redispersedin

mon

omer

andsonicatedat

120W

and60

KHzfor

3minutes

(i)Im

pactstr

ength

(ii)C

olor

stability

(iii)Th

ermal

cond

uctiv

ity

80x10

x4mm

35x15

x05mm

40x25mm

(i)Increased

(ii)Increased

colorstabilityfor

testgrou

ps

(iii)Noeffect

Alra

hlah

etal

2018

[26]

80-100

nm

0 1 2 3

Heatcurea

crylic

resin

(Lucito

ne550Dentsp

lyInt

IncPaU

SA)

(i)Hardn

essa

ndmod

ulus

(ii)T

gdegradation

temperatureand

rate

(iii)Cr

eep-recovery

andrelaxatio

nbehavior

(iv)A

ntibacteria

ladhesio

n

50x10

mm

discs

cutindifferent

sizes

ford

ifferent

tests

7mg

5x10

mm

(i)Increased

(ii)S

light

increase

with

2nano

-fillerc

ontent

(iii)Im

provem

entinbehavior

(iv)D

ecreaseinbacterial

attachmentcon

tent

Karcietal2018

[27]

13nm

0 1 3 5

(i)Au

to-polyeriz

ed(H

eraeus

Kulze

rNew

bury

Berkshire

UK)

(ii)

Heat-p

olym

erized

Heraeus

Kulze

rNew

bury

Berkshire

UK

(iii)Microwave-

polymerized

(GC

DentalTo

kyo

Japan)

(i)TiO2NPwe

remixed

with

acrylic

resin

powd

erusing

ballmillingat40

0rpm

for2

hours

(i)Flexuralstr

ength

65x10

x3mm

(i)Increasedforh

eat-and

auto-polym

erized

acrylic

at1

(ii)D

ecreased

fora

lltypeso

facrylic

at5

12 International Journal of Biomaterials

Table1Con

tinued

Authorsyear

Particlesiz

eAd

ditio

npercentage

Type

ofAc

rylic

Nanocom

positep

reparatio

nProp

ertie

stested

Specim

ensiz

eEff

ects

(IncreaseD

ecreaseUnchanged)

Totu

etalTo

tuet

al2

017[28]

ldquoAnatase

phaserdquo

0 02

04

06 10

25

(i)PM

MA-

MA

(ii)P

MMA-

MMA-

BPO

(iii)3D

printed

PMMA(eD

Envisio

nTec

GmbH

Gladb

eck

Germany)

(i)TiO2mod

ified

bymethacrylicacid

then

manually

mixed

with

PMMAmixture

(i)Th

ermalsta

bility

(ii)T

g

Stereolitho

graphic

dentures

(i)Increased(im

proved)

(ii)Increased

Totu

etal2018

[29]

ldquoAnatase

phaserdquo

0 02

04

06 10

20 25 50

PMMAfor3

Dprintin

g(eDent

100En

visio

nTec

GmbH

Gladb

eck

Germany)

(i)Re

sistance

(ii)E

lectric

alcond

uctiv

ity

(iii)Dielectric

constant

(i)Decreased

with

1020

25

and5

(ii)Increased

butm

aterialstill

maintainedinsulatin

gprop

ertie

s

(iii)Increasedwith

5

International Journal of Biomaterials 13

Conflicts of Interest

The authors declare that they have no conflicts of interest

References

[1] R L Sakaguchi and J M Powers Craigrsquos Restorative DentalMaterials Elsevier Health Sciences Philadelphia PA USA pp163-176 2012

[2] N Murakami N Wakabayashi R Matsushima A Kishidaand Y Igarashi ldquoEffect of high-pressure polymerization onmechanical properties of PMMA denture base resinrdquo Journalof the Mechanical Behavior of Biomedical Materials vol 20 pp98ndash104 2013

[3] R Adhikari and G H Michler ldquoPolymer nanocompositescharacterization by microscopyrdquo Polymer Reviews vol 49 no3 pp 141ndash180 2009

[4] A Navidfar T Azdast and A Karimzad Ghavidel ldquoInfluenceof processing condition and carbon nanotube on mechani-cal properties of injection molded multi-walled carbon nan-otubepoly(methyl methacrylate) nanocompositesrdquo Journal ofApplied Polymer Science vol 133 no 31 Article ID 43738 pp1ndash9 2016

[5] P Chaijareenont H Takahashi N Nishiyama and M Ark-sornnukit ldquoEffect of different amounts of 3-methacryloxypro-pyltrimethoxysilane on the flexural properties and wear resis-tance of alumina reinforced PMMArdquo Dental Materials vol 31no 4 pp 623ndash628 2012

[6] J Jordan K I Jacob R TannenbaumMA Sharaf and I JasiukldquoExperimental trends in polymer nanocompositesmdasha reviewrdquoMaterials Science and Engineering A vol 393 no 1-2 pp 1ndash112005

[7] MMGad SM Fouda F A Al-Harbi RNapankangas andARaustia ldquoPMMAdenture base material enhancement A reviewof fiber filler and nanofiller additionrdquo International Journal ofNanomedicine vol 12 pp 3801ndash3812 2017

[8] F Li S Zhou B You and L Wu ldquoKinetic study onthe UV-induced photopolymerization of epoxy acrylateTiO2nanocomposites by FTIR spectroscopyrdquo Journal of AppliedPolymer Science vol 99 no 6 pp 3281ndash3287 2006

[9] A Chatterjee ldquoProperties improvement of PMMA using nanoTiO2rdquo Journal of Applied Polymer Science vol 118 no 5 pp2890ndash2897 2010

[10] P Harini K Mohamed and T V Padmanabhan ldquoEffect ofTitanium dioxide nanoparticles on the flexural strength ofpolymethylmethacrylate An in vitro studyrdquo Indian Journal ofDental Research vol 25 no 4 pp 459ndash463 2014

[11] G Venkatesh Anehosur R D Kulkarni M G Naik et alldquoSynthesis and Determination of Antimicrobial Activity ofVisible Light Activated TiO2 Nanoparticles with PolymethylMethacrylate Denture Base Resin Against StaphylococcusAureusrdquo Journal of Gerontology ampGeriatric Research vol 01 no01 pp 103ndash111 2012

[12] A Sodagar A Bahador S Khalil A Saffar Shahroudi and MZaman Kassaee ldquoThe effect of TiO

2and SiO

2nanoparticles on

flexural strength of poly (methyl methacrylate) acrylic resinsrdquoJournal of Prosthodontic Research vol 57 no 1 pp 15ndash19 2013

[13] I M Hamouda and M M Beyari ldquoAddition of glass fibers andtitanium dioxide nanoparticles to the acrylic resin denture basematerial comparative study with the conventional and highimpact typesrdquo Oral Health and Dental Management vol 13 pp107ndash112 2014

[14] E E Totu C M Cristache E Voicila et al ldquoOn physicaland chemical characteristics of Poly(methylmethacrylate) na-nocomposites for dental applications IrdquoMateriale Plastice vol54 no 4 pp 666ndash672 2017

[15] S Shirkavand and EMoslehifard ldquoEffect of TiO2 nanoparticleson tensile strength of dental acrylic resinsrdquo Journal of DentalResearch Dental Clinics Dental Prospects vol 8 no 4 pp 197ndash203 2014

[16] M Karci N Demir and S Yazman ldquoEvaluation of FlexuralStrength of Different Denture Base Materials Reinforced withDifferent Nanoparticlesrdquo Journal of Prosthodontics 2018

[17] O Gurbuz F Unalan and I Dikbas ldquoComparison of thetransverse strength of six acrylic denture resinsrdquo OhdmbscMagazines vol 9 pp 21ndash24 2010

[18] S A Alwan and S S Alameer ldquoThe Effect of the Addition ofSilanized Nano Titania Fillers on Some Physical and Mechan-ical Properties of Heat Cured Acrylic Denture Base MaterialsrdquoJournal of Baghdad College of Dentistry vol 27 no 1 pp 86ndash912015

[19] M Ashour Ahmed M El-Shennawy Y M Althomali andA A Omar ldquoEffect of Titanium Dioxide Nano Particles In-corporation on Mechanical and Physical Properties on TwoDifferent Types of Acrylic Resin Denture Baserdquo World Journalof Nanoscience and Engineering vol 06 no 03 pp 111ndash119 2016

[20] A Sodagar S Khalil M Z Kassaee A S Shahroudi B Pourak-bari and A Bahador ldquoAntimicrobial properties of poly (methylmethacrylate) acrylic resins incorporated with silicon dioxideand titanium dioxide nanoparticles on cariogenic bacteriardquoJournal of Orthodontic Science vol 5 no 1 pp 7ndash13 2016

[21] M A Ahmed A A Omar M El-Shennawy M I Ebrahimand Y M Althomali ldquoInfluence of addition of different types ofnano-fillers on the microstructure and mechanical propertiesof PMMA based denture resinrdquo Kasmera Journal vol 45 pp48ndash59 2017

[22] MHashemM F Al Rez H Fouad et al ldquoInfluence of titaniumoxide nanoparticles on the physical and thermomechanicalbehavior of poly methyl methacrylate (pmma) A denture baseresinrdquo Science of Advanced Materials vol 9 no 6 pp 938ndash9442017

[23] L Ghahremani S Shirkavand F Akbari and N SabzikarildquoTensile strength and impact strength of color modified acrylicresin reinforcedwith titaniumdioxide nanoparticlesrdquo Journal ofClinical and Experimental Dentistry vol 9 no 5 pp e661ndashe6652017

[24] E E Totu A C Nechifor G Nechifor H Y Aboul-Eneinand C M Cristache ldquoPoly(methyl methacrylate) with TiO2nanoparticles inclusion for stereolitographic complete denturemanufacturing minus the fututre in dental care for elderly edentu-lous patientsrdquo Journal of Dentistry vol 59 pp 68ndash77 2017

[25] H K Aziz ldquoTiO-Nanofillers Effects on Some Properties ofHighly- Impact Resin Using Different Processing TechniquesrdquoThe Open Dentistry Journal vol 12 no 1 pp 202ndash212 2018

[26] M Tsuji T Ueda K Sawaki M Kawaguchi and K SakuraildquoBiocompatibility of a titanium dioxide-coating method fordenture base acrylic resinrdquo Gerodontology vol 33 no 4 pp539ndash544 2016

[27] S PodzimekM Tomka P Sommerova Y Lyuya-Mi J Bartovaand J Prochazkova ldquoImmune markers in oral discomfortpatients before and after elimination of oral galvanismrdquo Neu-roendocrinology Letters vol 34 no 8 pp 802ndash808 2013

[28] S Kiat-amnuayM Beerbower JM Powers andRD ParavinaldquoInfluence of pigments and opacifiers on color stability of

14 International Journal of Biomaterials

siliconemaxillofacial elastomerrdquo Journal ofDentistry vol 37 no1 pp e45ndashe50 2009

[29] S H Tuna F Keyf H O Gumus and C Uzun ldquoThe evaluationof water sorptionsolubility of various acrylic resinsrdquo EuropeanJournal of Dental Education vol 2 pp 191ndash197 2008

[30] S M Khaled R Sui P A Charpentier and A S RizkallaldquoSynthesis of TiO

2-PMMA nanocomposite using methacrylic

acid as a coupling agentrdquo Langmuir vol 23 no 7 pp 3988ndash39952007

[31] L Reijnders ldquoThe release of TiO2 and SiO2 nanoparticles fromnanocompositesrdquo Polymer Degradation and Stability vol 94no 5 pp 873ndash876 2009

[32] G Nazirkar S Bhanushali S Singh B Pattanaik and N RajldquoEffect of Anatase Titanium Dioxide Nanoparticles on theFlexural Strength of Heat Cured Poly Methyl MethacrylateResins An In-Vitro Studyrdquo Journal of Indian ProsthodontistSociety vol 14 pp 144ndash149 2014

[33] A Chatterjee ldquoEffect of nanoTiO2addition on poly(methyl

methacrylate) an exciting nanocompositerdquo Journal of AppliedPolymer Science vol 116 no 6 pp 3396ndash3407 2010

[34] S Rashahmadi R Hasanzadeh and S Mosalman ldquoImprov-ing the Mechanical Properties of Poly Methyl MethacrylateNanocomposites for Dentistry Applications Reinforced withDifferent Nanoparticlesrdquo PolymermdashPlastics Technology andEngineering vol 56 no 16 pp 1730ndash1740 2017

[35] A H Yuwono B Liu J Xue et al ldquoControlling the crystallinityand nonlinear optical properties of transparent TiO

2-PMMA

nanohybridsrdquo Journal of Materials Chemistry vol 14 no 20 pp2978ndash2987 2004

[36] J K Pandey K RaghunathaReddy A P Kumar andR P SinghldquoAn overviewon the degradability of polymer nanocompositesrdquoPolymer Degradation and Stability vol 88 no 2 pp 234ndash2502005

[37] C Tao S Jianping J Weng L Ting and H Xiaozhu ldquoPrepara-tion and properties of PMMATiO2 nanocompositerdquoChemicalReaction Engineering andTechnology vol 23 pp 435ndash440 2007

[38] A H Yuwono J Xue J Wang et al ldquoTransparent nanohybridsof nanocrystalline TiO2 in PMMA with unique nonlinearoptical behaviorrdquo Journal of Materials Chemistry vol 13 no 6pp 1475ndash1479 2003

[39] R Alla K N Raghavendra R Vyas and A KonakanchildquoConventional and contemporary polymers for the fabricationof denture prosthesis Part I overview composition and proper-tiesrdquo International Journal of Applied Dental Sciences vol 1 noPart I pp 82ndash89 2015

[40] C C Trapalis P Keivanidis G Kordas et al ldquoTiO2(Fe3+)nanostructured thin films with antibacterial propertiesrdquo ThinSolid Films vol 433 no 1-2 pp 186ndash190 2003

[41] L S Acosta-Torres L M Lopez-Marın R E Nunez-Anita GHernandez-Padron and V M Castano ldquoBiocompatible Metal-Oxide Nanoparticles Nanotechnology Improvement of Con-ventional Prosthetic Acrylic Resinsrdquo Journal of Nanomaterialsvol 2011 Article ID 941561 8 pages 2011

[42] A Bahador S Khalil B Pourakbari et al ldquoPhotocatalyticEffects of Acrylic Resins Incorporated with Nano-titaniumDioxide on Planktonic and Biofilm Growth of Four CariogenicBacteriardquo Annual Research amp Review in Biology vol 4 no 17pp 2695ndash2708 2014

[43] A Alrahlah H Fouad M Hashem A Niazy and A AlBadahldquoTitanium Oxide (TiO2)Polymethylmethacrylate (PMMA)Denture Base Nanocomposites Mechanical Viscoelastic and

Antibacterial BehaviorrdquoMaterials vol 11 no 7 Article ID 1096pp 10961ndash109615 2018

[44] A Kubacka M Ferrer M L Cerrada et al ldquoBoostingTiO2-anatase antimicrobial activity Polymer-oxide thin filmsrdquoApplied Catalysis B Environmental vol 89 no 3-4 pp 441ndash4472009

[45] Y Cheng T Sakai R Moroi et al ldquoSelf-cleaning abilityof a photocatalyst-containing denture base materialrdquo DentalMaterials vol 27 no 2 pp 179ndash186 2008

[46] C M Bollen P Lambrechts and M Quirynen ldquoComparisonof surface roughness of oral hard materials to the thresholdsurface roughness for bacterial plaque retention a review of theliteraturerdquoDental Materials vol 13 no 4 pp 258ndash269 1997

[47] N Elshereksi M Ghazali A Muchtar and C Azhari ldquoEffectof nanobarium titanate addition on the surface characteristicsof denture base resinrdquo International Journal of Mechanical andProduction Engineering vol 5 pp 1ndash8 2017

[48] Y Xia Z Feimin H Xie and N Gu ldquoNanoparticles reinforcedresin based dental compositesrdquo Journal of Dentistry vol 36 pp450ndash455 2008

[49] S Mosalman S Rashahmadi and R Hasanzadeh ldquoThe effectof TiO2 nanoparticles on mechanical properties of poly methylmethacrylate nanocompositesrdquo International Journal of Engi-neering Transactions B Applications vol 30 no 5 pp 807ndash8132017

[50] Y Han S Kiat-amnuay J M Powers and Y Zhao ldquoEffectof nano-oxide concentration on the mechanical properties ofa maxillofacial silicone elastomerrdquo The Journal of ProstheticDentistry vol 100 no 6 pp 465ndash473 2008

[51] I N Safi ldquoEvaluation the effect of nanomdashfillers (TiO2 AL2O3

SiO2) addition on glass transition temperature E-moudulus

and coefficient of thermal expansion of acrylic denture basematerialrdquo Journal of Baghdad College of Dentistry vol 26 no1 pp 37ndash41 2014

[52] W Wang S Liao Y Zhu M Liu Q Zhao and Y Fu ldquoRecentApplications of Nanomaterials in Prosthodonticsrdquo Journal ofNanomaterials vol 2015 Article ID 408643 11 pages 2015

[53] L Sun R F Gibson F Gordaninejad and J Suhr ldquoEnergyabsorption capability of nanocomposites A reviewrdquoCompositesScience and Technology vol 69 no 14 pp 2392ndash2409 2009

[54] S Podzimek K Hana M Miksovsky et al ldquoThe Influence ofgalvanic currents and voltage on the proliferation activity oflymphocytes and expression of cell surface moleculesrdquo FoliaBiologica vol 54 no 5 pp 146ndash150 2008

[55] E E Totu E Voicila V Pistritu G Nechifor and C MCristache ldquoEvaluation of electrical characteristics for PMMA-TiO2 nanocomposites used in dentistryrdquo Evista de Chimie vol69 no 1 pp 155ndash159 2018

CorrosionInternational Journal of

Hindawiwwwhindawicom Volume 2018

Advances in

Materials Science and EngineeringHindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

Journal of

Chemistry

Analytical ChemistryInternational Journal of

Hindawiwwwhindawicom Volume 2018

ScienticaHindawiwwwhindawicom Volume 2018

Polymer ScienceInternational Journal of

Hindawiwwwhindawicom Volume 2018

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Advances in Condensed Matter Physics

Hindawiwwwhindawicom Volume 2018

International Journal of

BiomaterialsHindawiwwwhindawicom

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Applied ChemistryJournal of

Hindawiwwwhindawicom Volume 2018

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Hindawiwwwhindawicom Volume 2018

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Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawiwwwhindawicom

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Volume 2018

TribologyAdvances in

Hindawiwwwhindawicom Volume 2018

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Advances inPhysical Chemistry

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BioMed Research InternationalMaterials

Journal of

Hindawiwwwhindawicom Volume 2018

Na

nom

ate

ria

ls

Hindawiwwwhindawicom Volume 2018

Journal ofNanomaterials

Submit your manuscripts atwwwhindawicom

6 International Journal of Biomaterials

145 Water Sorption Solubility and Porosity Conventionalacrylic resins have voids and porosities that allow watermolecules exchange which could be the leading cause forwater sorption and solubility [18]The nature of denture resinmaterial allows it to absorb water which acts as a plasticizerand affects the material dimensional stability and denturedurability [41]Thewatermolecules force themselves betweenpolymer chains move them apart create internal stressesand result in crack formation [29] As reported by Alwan andAlameer [18] the addition of TiO

2NP to heat cure acrylic

resin decreases water sorption and solubility significantlycompared to pure PMMA Torres et al (2011) concludedthat PMMA-TiO

2-Fe2O3nanocomposites had lower sorption

and porosity values compared to pure PMMA but similarsolubility levels However the solubility levels were originallylow which is important to prevent the adverse effects on oralstructures or polymer functions [41] Also as thematerial getsmore homogenous it becomes less soluble with lower watersorption levels [29]

Therefore the addition of TiO2NP fills the microvoids

and polymer interstitial spaces decreasing the ability ofcomposite material to absorb water In addition to thatTiO2NP are insoluble in water and these particles partly

replace the hydrophilicmatrix which decreases water uptakeThe use of silane-coupling agent in silanization process ofTiO2NP could lead to a reduction in the amount of water that

reaches the inner layers of polymer matrix [18]

146 Thermal Properties The addition of 3 TiO2NP to

PMMA had no effect on thermal conductivity [25]The glasstransition temperature (Tg) test is done to understand thethermal stability and determine the temperature at whichthe material starts to degrade As the percentage of TiO

2NP

increases the Tg of nanocomposite increases linearly up to75wt TiO

2 Pure PMMA is stable up to 134∘C (1 weight

loss) while PMMA2wtTiO2and PMMA5wtTiO

2are

stable up to 154∘C and 180∘C respectively Tg was improvedby 15ndash34 with 2ndash5 addition of TiO

2NP respectively

However further addition of TiO2NP caused a decrease in

thermal stability [33] Another study by Safi (2014) reportedthe positive effect of TiO

2NP addition on the Tg temperature

of acrylic resin [51] In a recent study [43] authors evaluatedthe effect of adding 1 2 and 3 TiO

2NP to PMMA on

thermal behavior and found a slight effect on Tg degradationtemperature and rate

Chatterjee (2010) in another study reported that theaddition of 5wt TiO

2NP caused a 23 increase in Tg and

this improvement reached only 3 when the amount ofTiO2NPwas increased to 15 [9] Also pure PMMA showed

5 weight loss at 217∘C while a higher temperature (310∘C)was needed to create the same effect in the PMMA5wtTiO

2

[9] Recently Totu et al (2018) [14] confirmed the increasein decomposition temperature for PMMATiO

2NP compos-

ite suggesting an improved thermal stability This may beexplained by the reduced intercrystalline distance interac-tion and bond formation betweennanoparticles and polymerchains or the absorption of some energy by the titania par-ticles increasing the thermal stability Final decompositionof the PMMATiO

2NP composite happened at temperatures

620-700∘C with decreasing pattern of the total mass loss asthe amount of nanoparticles increased

The thermal stability of TiO2NP added to PMMA inhibits

the degradation of the resin and improves the thermalstability of the composite material [33] Another explanationfor thermal stability is the migration of TiO

2NP with low

surface energy to the surface of the PMMA resin to forma heat resistant layer [9] The decrease in thermal stabilitywith higher amount of nanofiller may be attributed to theagglomeration of filler particles rather than forming a filler-to-matrix interaction This agglomeration reduces the effectof heat retardation associated with TiO

2NP [33] TiO

2NP

crystalline phase has free electrons that can be associatedwithsurface reactions Oxygen that diffused in the nanocompositesamples was absorbed on the surface of TiO

2NP Hence

diffused oxygen amount in the PMMAmatrix was lower thanin pure PMMA which led to the slower thermooxidativedegradation of the PMMAmatrix [9 33]

It is knows that PMMA shrinks upon polymerizationcausing dimensional changes in the final product Dimen-sional stability is also affected by coefficient of thermalexpansion The result of a study by Hashem et al (2017)[22]showed that pure PMMA and PMMA3TiO

2started to

disintegrate and lose weight at 200∘C with 90 weightloss happening at 400∘C for both materials suggesting nosignificant effect of TiO

2NPon themelting temperature of the

composite material This might be explained by the minimalamount of filler addition or the presence of large number ofdecomposition sites within the material [22]

147 Viscoelastic Behavior Little work has been doneon the effects of TiO

2NP on the viscoelastic behavior

(creep-recovery and relaxation) behavior of PMMA matrixRecently in a study by Alrahlah done to investigate vis-coelastic properties of TiO

2NP-modified PMMA denture

base composite it was found that the creep-recovery andrelaxation behaviors of PMMA were significantly improveddue to the addition of TiO

2NPAlso the improvement further

increased as the concentration of the nanofiller changed from1 to 3This improvement in the behavior indicates the roleof the nanoparticles in increasing the stiffness of the PMMAmatrix owing to the reduction in its molecular mobility andfree volume [43]

148 Electrical Behavior It is imperative to avoid prolongedcontact between oral mucosa and materials with high elec-trical conductivity Metallic particles present in restorativematerials my produce a galvanic effect in the highly con-ductive oral environment causing oral discomfort changesin cell proliferation and immune markers [27 54] Totu andcolleagues (2018) [55] studied the effect of adding differentpercentages of TiO

2NP (0 (control) 02 04 06

10 20 25 and 5) to PMMA used for 3D printingon the electrical properties of the resulting nanocompositeThey reported a decrease in material resistance with theadditions of ge1 TiO

2NP Also an increase in electrical con-

ductivity was noted with the addition of 5 TiO2NP How-

ever the composite material still maintained its insulatingproperty

International Journal of Biomaterials 7

2 Overall Performanceand Clinical Significance

It is well understood that advancements in biomaterialscience affect the progression of technologies in any fieldincluding dental prostheses The introduction of nanomate-rials had significantly changed the clinical and technolog-ical aspects of dentistry In this paper the latest researchprogress on the applications of TiO

2NP in prosthodontics

was reviewed It clearly shows varying responses of phys-ical and mechanical properties of the modified materialswhere a number of properties improved others deterio-rated and few did not change Their level of effectivenessas shown in the literature is diverse being more or lesseffective than pure materials Therefore to attain removableprostheses with improved properties and acceptable clinicalperformance the material of manufacture (acrylic resin)can be enhanced by adding proper percentage of nanofillerinitial surface treatment of the nanoparticles and appro-priate selection of addition method Authors hope that thisreview article would provide some valuable elicitation forfuture scientific and technological innovations in the relatedfield

Based on this review TiO2NPwere found to be enhancers

in some aspects modifiers in some and insignificant in oth-ers The effect depends mainly on NP size addition methodsurface treatment and loading percentage Although the sizeof NP ranged between 5 nm and 350 nm the results of thestudies were not justified based on the nanofiller size anda clear link between size and effect was not established Forthat further investigations to relate the resulting propertiesto nanoparticle size are required

Variations in the results were mainly related to fillermode of addition The addition of nanoparticles to acrylicmonomer was considered more effective owing to betterdispersion of NP within the monomer In this method thedominant improvement was noticed in mechanical prop-erties while physical properties were slightly affected It isworth noting that with this technique the polymer monomerratio may be affected Therefore mixing the nanofillerwith acrylic powder has been suggested and studied Tillnow no study can be found that compares between theeffects of different modes of addition (nanofillers additionto powder or monomer) Based on this review furtherinvestigations of the above-mentioned point are necessaryas well as the proper way to establish the proportion ofpolymermonomer ratio for each method hence nanofilleraddition interferes with the manufacturersquos recommendedratios

The percentage of addition also plays a role in resultingproperties While the range of addition was very broad(05ndash30wt) low percentages resulted in improved prop-erties compared to higher percentages Simple addition of1ndash2wt ratios exhibited improved properties while increas-ing the filler content more than 5wt significantly weakenedthe final nanocomposites In fact the bonding betweenTiO2NP and resin matrix is a critical factor to achieve the

desired properties of nanocomposite As showed in Table 1the treatment of NPwith saline coupling agents improved the

properties in comparison to untreated particles ThereforeNP surface treatment is recommended

According to Table 1 inconsistencies in prepared spec-imen sizes for the same test were seen which may havecontributed to variations in the results between studiesexperimenting with the same filler percentage This reflectsa major error in the methodologies of the studies where thetest should have been done according to standardized spec-imensrsquo dimensions and testing procedures Testing shouldfollow an internationally accepted standardization proto-col like the ADA specifications for denture base polymersto make it possible to compare results between differentstudies

Titanium nanoparticles remain under focus because ofthe antimicrobial efficacy against candida species despitetheir negative effect on a number of properties Incorporationof TiO

2NP into PMMA matrix proved to have antimicrobial

effects specifically on candida species [24] Not to be lost inthis discussion is the effect of TiO

2NP surface modification

on antimicrobial properties of the final product It was shownthat modification with noble metals such as (Ag Au Ptand Pd) on TiO

2NP surface enhanced the photocatalytic

ability of the nanoparticles and bactericidal activity thereafter[12]

Even with this number of studies on recently introducedTiO2NP into PMMA no clear evidence on the clinical

applicability of this nanocomposite has been demonstratedFurther investigations are required to interpret and confirmthe chemical structure changes in PMMATiO

2nanocom-

posite and also to determine the need from otherwise forsurface treatment as well as the proper percentage of additionthat will not affect the final product adversely

Research to improve upon existing nanomaterials is stillongoing with emphasis on efficiency Although the sciencebehind nanotechnology is intriguing the lack of long-termevidence addressing their clinical performance restricts theirwide clinical use Overall there is an essential requirement toinvestigate the durability of these PMMATiO

2composites in

different environmental conditions to extend the applicabilityof these hybrid materials

3 Conclusion

Based on the current review we could conclude thatthe addition of TiO

2NP to PMMA denture bases is still

questionable for working as a reinforcing material andrequires further investigations following the ADA specifica-tions These investigations must explore the chemical andstructural changes happening in the nanocomposite afterTiO2addition The improvements in properties mentioned

above were dominantly seen with lower concentrations ofTiO2and the increase in the amount of added nanopar-

ticles caused adverse effects on resulting PMMATiO2

compositeIn conclusion there is an essential need to investigate the

clinical performance and durability of these nanocompositesin different conditions simulating the oral environment toverify their applicability and provide an insight of possiblefuture researches in this field

8 International Journal of Biomaterials

Table1TiO2NPapplications

indentureb

asea

ndits

effecto

nthetestedprop

ertie

s

Authorsyear

Particlesiz

eAd

ditio

npercentage

Type

ofAc

rylic

Nanocom

positep

reparatio

nProp

ertie

stested

Specim

ensiz

eEff

ects

(IncreaseD

ecreaseUnchanged)

Chatterje

e2010

[9]

5nm

0-15w

tPM

MAfro

mScientificP

olym

erProd

ucts(O

ntario

NY)

(i)MeasuredTiO2NPmixed

with

PMMAfor5

-10min

(ii)D

ACAtwin-screw

extractio

nprocessa

t190∘C

and100rpm

(iii)Ac

rylic

mixed

for6

-7min

andextrud

ed5tim

es

(i)Tensile

mod

ulus

(ii)D

imensio

nal

stability

(iii)Glasstransition

temperature(T

g)

(iv)U

Vabsorptio

n

10x6x03m

m

5mg

(i)Im

provem

entintensile

mod

ulus

(ii)Increased

thermalsta

bility

(iii)IncreasedT g

(iv)Improvem

entinUV

absorptio

n997888rarr

maxim

umat2

TiO2NP

Chatterje

e2010

[10]

5nm

0 20

50 75

100

150

300

PMMAfro

mScientificP

olym

erProd

ucts(O

ntario

NY)

(i)MeasuredTiO2NPmixed

with

PMMAfor5

-10min

(ii)D

ACAtwin-screw

extractio

nprocessa

t190∘C

and100rpm

(iii)Ac

rylic

mixed

for6

-7min

andextrud

ed5tim

es

(i)Glasstransition

temperature(T

g)

(ii)Th

ermalsta

bility

(iii)Decom

position

temperature

10x6x03m

m

(i)T g

increasedlin

early

upto

75TiO2NP

(ii)Th

ermalsta

bilityincreased

(2-15

TiO2NP)

(iii)Decom

position

temperaturesincreased

with

filler

contentu

pto

10TiO2NP

Aneho

suretal

2012

[11]

31nm

ldquoAnataseph

aserdquo

30

Inadditio

nto

surfa

cecoating

DPI

heatcure

acrylic

resin

(In

dia)

(i)Visib

lelig

htactiv

ated

TiO2NPwe

remixed

with

methylm

ethacrylate

mon

omer

(i)Microbial

inhibitory

effect

againstSA

ureus

5x5x2mm

(i)3w

of

TiO2show

santim

icrobialactiv

ityagainstS

Au

reus

Sodagare

tal2013

[12]

21nm

ldquoAnatase

phaserdquo

0 05 10

SelectaP

lus

(self-c

urea

crylic

resin

)

(i)TiO2NPwe

readdedto

acrylic

mon

omer

(i)Flexuralstr

ength

50x10

x33m

m(i)

Flexuralstr

engthdecreasedas

thefi

llerc

ontent

increased

(i)Flexuralmod

ulus

(i)Nochange

inflexu

ral

mod

ulus

Ham

ouda

and

Beyari

2014

[13]

21nm

50

Con

ventionalh

eat

cure

acrylic

resin

(AcrostonWHN

England)

andhigh

impact(M

etrocryl

HiMetrodent

LTDE

ngland

)

(i)TiO2NPwe

remixed

thorou

ghlywith

acrylic

powd

erby

hand

(ii)F

lexu

ral

strength

(iii)To

ughn

ess

65x10

x25mm

(ii)F

lexu

ralstre

ngth

and

toug

hnessd

ecreased

(iv)M

onom

errelease

(iii)Nodifferenceb

etwe

encontroland

TiO2reinforced

regardingmon

omer

release

International Journal of Biomaterials 9

Table1Con

tinued

Authorsyear

Particlesiz

eAd

ditio

npercentage

Type

ofAc

rylic

Nanocom

positep

reparatio

nProp

ertie

stested

Specim

ensiz

eEff

ects

(IncreaseD

ecreaseUnchanged)

Nazirk

aretal

2014

[14]

7nm

ldquoAnatase

phaserdquo

0 05 10

DPI

heatcure

acrylic

resin

(i)TiO2NPaddedto

acrylic

mon

omer

(i)Flexuralstr

ength

65x10

x33mm

(i)Flexuralstr

engthdecreasedas

theT

iO2am

ount

increased

Shirk

avandand

Moslehifard2014

[15]

lt25

nm(averagesim204

nm)

ldquoAnataseand

Rutilep

hasesrdquo

0 05 10

20

Heatcurea

crylic

resin

from

Ivoclar

Vivadent

(i)TiO2NPwe

remixed

with

thea

crylicresin

polymer

inan

amalgamator

for2

0min

(i)Tensile

strength

60x12

x4mm

(i)Tensile

strengthandelastic

mod

ulus

improved

with

1TiO2NP

(ii)0

5and2

TiO2we

reno

tsig

nificantly

different

from

each

othero

rcon

trol

Harinietal2014

[16]

0 10

20

50

Clearh

eatcure

acrylic

resin

(i)Nanop

artic

lesw

ere

incorporated

into

mon

omer

byultrason

icdispersio

n(i)

Flexuralstr

ength

65x10

x3mm

(i)Flexuralstr

engthim

proved

with

TiO2additio

nsig

nificant

differencen

oticed

with

5

Safi2014

[17]

50

Heatcured

enture

base

acrylic

(Sup

eracrylplus

Czecho

slovakia)

(i)Nanop

artic

lesa

dded

tomon

omer

andsonically

dispersed

(i)Coefficientof

thermalexpansion

(ii)M

odulus

(iii)Glasstransition

15x6mm

Cylin

ders

65x10

x25mm

Powd

erform

(10g)

(i)Decreaseincoeffi

cientof

thermalexpansion

(ii)D

ecreased

inmod

ulus

ofelastic

ity

(iii)IncreasedT g

Alwanand

Alameer2015

[18]

lt50

nmsiz

e0 30

(i)Silanizedwith

TMSP

M

Heatcurea

crylic

resin

(i)SilanizedTiO2NPwe

readdedto

mon

omer

and

sonicated

(i)Im

pactstr

ength

(ii)T

ransverse

strength

(iii)Hardn

ess

(iv)S

urface

roug

hness

(v)W

atersorptio

nandsolubility

80x10

x4mm

65x10x25m

m

50x05m

mdisc

(i)Increased

(ii)Increased

(iii)Increased

(iv)Increased

(v)D

ecreased

10 International Journal of Biomaterials

Table1Con

tinued

Authorsyear

Particlesiz

eAd

ditio

npercentage

Type

ofAc

rylic

Nanocom

positep

reparatio

nProp

ertie

stested

Specim

ensiz

eEff

ects

(IncreaseD

ecreaseUnchanged)

Ahm

edetal2016

[19]

46nm

0 10

50

Con

ventionalh

eat

cure

acrylic

resin

(ImplacrylVe

rtex)

andhigh

impact

heatcureacrylic

resin

(Vertex-Dental

Netherla

nds)

(i)TiO2NPwe

readdedinto

acrylic

resin

(i)Flexuralstr

ength

(ii)Impactstr

ength

(iii)Hardn

ess

50x10

x3mm

60x6x4mm

25x10

x3mm

(i)Decreased

with

TiO2

additio

n

(ii)Increased

onlyfor

conventio

nalacrylicresin

mod

ified

by1

(iii)Increasedwith

5additio

nTiO2NPforb

othtypeso

facrylic

Sodagare

tal2016

[20]

21nm

05 10

SelectaP

lus

(self-c

urea

crylic

resin

)

(i)Nanop

artic

lesw

erea

dded

toacrylic

mon

omer

and

stirred

(i)Antim

icrobial

prop

ertie

s20

x20

x1m

m

(i)TiO2redu

cedmicrobial

grow

thatbo

thconcentrations

at90

min

underU

VAexpo

sure

(ii)A

ntim

icrobialactiv

ityof

TiO2istim

edependent

Ahm

edetal2017

[21]

lt25

nm0 05 10

Heatcurea

crylic

resin

from

Dentsp

lyInternationalInc

(ChicagoIL

USA

)

(i)TiO2NPwe

readdedto

acrylic

polymer

andmixed

usingam

algam

capsule

(i)Flexuralstr

ength

(ii)F

racture

toug

hness

(iii)Hardn

ess

65x10

x25mm

65x10

x25mm

30x10

x25mm

(i)Increasedwith

both

filler

percentages

(ii)N

oeffecto

nfracture

toug

hnesso

fbothfiller

percentages

(iii)Increasedwith

1filler

Hashem

etal2

017

[22]

90nm

0 10

20 30

Self-cureacrylic

resin

from

Eco-crylcold

Protechn

o(Spain)

(i)TiO2NPwe

remixed

with

them

onom

er

(i)Flexuralmod

ulus

andflexu

ral

strength

(ii)H

ardn

ess

(iii)Surfa

cewe

tting

30x8x1m

m

50x1m

mdiscs

(i)Increasedlin

early

(ii)Increased

(iii)Re

ducedwith

1filler

contentand

increasedwith

high

erpercentages

(iv)T

gdecreasedwith

TiO2

additio

n

Ghahrem

anietal

2017

[23]

20-30nm

ldquoAnatase

phaserdquo

0 10

SRTriplexHot

heatcureacrylic

resin

(Ivoclar

Vivadent

Inc

Schaan

Liechtenste

in)

(i)TiO2NPwe

remixed

with

acrylic

resin

powd

erin

anultrason

icmixer

(i)Tensile

strength

(ii)Impactstr

ength

60x12

x39mm

75x10

x10

mm

(i)Increased

(ii)Increased

International Journal of Biomaterials 11Ta

ble1Con

tinued

Authorsyear

Particlesiz

eAd

ditio

npercentage

Type

ofAc

rylic

Nanocom

positep

reparatio

nProp

ertie

stested

Specim

ensiz

eEff

ects

(IncreaseD

ecreaseUnchanged)

Totu

etal2017

[24]

65-170

nm

0 02

04 1 25

PMMA+P

EMAfor

3Dprintin

g(eDent

100En

visio

nTec

GmbH

Gladb

eck

Germany)

(i)Nanop

artic

lesw

erea

dded

into

PMMAsolutio

nwith

continuo

usstirringand

ultrason

icmixingfor1

hour

(i)Antim

icrobial

effect(Ca

ndida

scotti)

(ii)C

omplete

denture

manufacturin

gusin

gste

reolith

ograph

y

(i)041

and25

inhibited

cand

idagrow

th

(ii)P

MMA04TiO2compo

site

successfu

llyused

ford

enture

fabrication

Aziz2018

[25]

30nm

0 30

Highim

pactheat

cure

acrylic

resin

(Vertex-Dental

Netherla

nds)-

(i)TiO2NPwe

redispersedin

mon

omer

andsonicatedat

120W

and60

KHzfor

3minutes

(i)Im

pactstr

ength

(ii)C

olor

stability

(iii)Th

ermal

cond

uctiv

ity

80x10

x4mm

35x15

x05mm

40x25mm

(i)Increased

(ii)Increased

colorstabilityfor

testgrou

ps

(iii)Noeffect

Alra

hlah

etal

2018

[26]

80-100

nm

0 1 2 3

Heatcurea

crylic

resin

(Lucito

ne550Dentsp

lyInt

IncPaU

SA)

(i)Hardn

essa

ndmod

ulus

(ii)T

gdegradation

temperatureand

rate

(iii)Cr

eep-recovery

andrelaxatio

nbehavior

(iv)A

ntibacteria

ladhesio

n

50x10

mm

discs

cutindifferent

sizes

ford

ifferent

tests

7mg

5x10

mm

(i)Increased

(ii)S

light

increase

with

2nano

-fillerc

ontent

(iii)Im

provem

entinbehavior

(iv)D

ecreaseinbacterial

attachmentcon

tent

Karcietal2018

[27]

13nm

0 1 3 5

(i)Au

to-polyeriz

ed(H

eraeus

Kulze

rNew

bury

Berkshire

UK)

(ii)

Heat-p

olym

erized

Heraeus

Kulze

rNew

bury

Berkshire

UK

(iii)Microwave-

polymerized

(GC

DentalTo

kyo

Japan)

(i)TiO2NPwe

remixed

with

acrylic

resin

powd

erusing

ballmillingat40

0rpm

for2

hours

(i)Flexuralstr

ength

65x10

x3mm

(i)Increasedforh

eat-and

auto-polym

erized

acrylic

at1

(ii)D

ecreased

fora

lltypeso

facrylic

at5

12 International Journal of Biomaterials

Table1Con

tinued

Authorsyear

Particlesiz

eAd

ditio

npercentage

Type

ofAc

rylic

Nanocom

positep

reparatio

nProp

ertie

stested

Specim

ensiz

eEff

ects

(IncreaseD

ecreaseUnchanged)

Totu

etalTo

tuet

al2

017[28]

ldquoAnatase

phaserdquo

0 02

04

06 10

25

(i)PM

MA-

MA

(ii)P

MMA-

MMA-

BPO

(iii)3D

printed

PMMA(eD

Envisio

nTec

GmbH

Gladb

eck

Germany)

(i)TiO2mod

ified

bymethacrylicacid

then

manually

mixed

with

PMMAmixture

(i)Th

ermalsta

bility

(ii)T

g

Stereolitho

graphic

dentures

(i)Increased(im

proved)

(ii)Increased

Totu

etal2018

[29]

ldquoAnatase

phaserdquo

0 02

04

06 10

20 25 50

PMMAfor3

Dprintin

g(eDent

100En

visio

nTec

GmbH

Gladb

eck

Germany)

(i)Re

sistance

(ii)E

lectric

alcond

uctiv

ity

(iii)Dielectric

constant

(i)Decreased

with

1020

25

and5

(ii)Increased

butm

aterialstill

maintainedinsulatin

gprop

ertie

s

(iii)Increasedwith

5

International Journal of Biomaterials 13

Conflicts of Interest

The authors declare that they have no conflicts of interest

References

[1] R L Sakaguchi and J M Powers Craigrsquos Restorative DentalMaterials Elsevier Health Sciences Philadelphia PA USA pp163-176 2012

[2] N Murakami N Wakabayashi R Matsushima A Kishidaand Y Igarashi ldquoEffect of high-pressure polymerization onmechanical properties of PMMA denture base resinrdquo Journalof the Mechanical Behavior of Biomedical Materials vol 20 pp98ndash104 2013

[3] R Adhikari and G H Michler ldquoPolymer nanocompositescharacterization by microscopyrdquo Polymer Reviews vol 49 no3 pp 141ndash180 2009

[4] A Navidfar T Azdast and A Karimzad Ghavidel ldquoInfluenceof processing condition and carbon nanotube on mechani-cal properties of injection molded multi-walled carbon nan-otubepoly(methyl methacrylate) nanocompositesrdquo Journal ofApplied Polymer Science vol 133 no 31 Article ID 43738 pp1ndash9 2016

[5] P Chaijareenont H Takahashi N Nishiyama and M Ark-sornnukit ldquoEffect of different amounts of 3-methacryloxypro-pyltrimethoxysilane on the flexural properties and wear resis-tance of alumina reinforced PMMArdquo Dental Materials vol 31no 4 pp 623ndash628 2012

[6] J Jordan K I Jacob R TannenbaumMA Sharaf and I JasiukldquoExperimental trends in polymer nanocompositesmdasha reviewrdquoMaterials Science and Engineering A vol 393 no 1-2 pp 1ndash112005

[7] MMGad SM Fouda F A Al-Harbi RNapankangas andARaustia ldquoPMMAdenture base material enhancement A reviewof fiber filler and nanofiller additionrdquo International Journal ofNanomedicine vol 12 pp 3801ndash3812 2017

[8] F Li S Zhou B You and L Wu ldquoKinetic study onthe UV-induced photopolymerization of epoxy acrylateTiO2nanocomposites by FTIR spectroscopyrdquo Journal of AppliedPolymer Science vol 99 no 6 pp 3281ndash3287 2006

[9] A Chatterjee ldquoProperties improvement of PMMA using nanoTiO2rdquo Journal of Applied Polymer Science vol 118 no 5 pp2890ndash2897 2010

[10] P Harini K Mohamed and T V Padmanabhan ldquoEffect ofTitanium dioxide nanoparticles on the flexural strength ofpolymethylmethacrylate An in vitro studyrdquo Indian Journal ofDental Research vol 25 no 4 pp 459ndash463 2014

[11] G Venkatesh Anehosur R D Kulkarni M G Naik et alldquoSynthesis and Determination of Antimicrobial Activity ofVisible Light Activated TiO2 Nanoparticles with PolymethylMethacrylate Denture Base Resin Against StaphylococcusAureusrdquo Journal of Gerontology ampGeriatric Research vol 01 no01 pp 103ndash111 2012

[12] A Sodagar A Bahador S Khalil A Saffar Shahroudi and MZaman Kassaee ldquoThe effect of TiO

2and SiO

2nanoparticles on

flexural strength of poly (methyl methacrylate) acrylic resinsrdquoJournal of Prosthodontic Research vol 57 no 1 pp 15ndash19 2013

[13] I M Hamouda and M M Beyari ldquoAddition of glass fibers andtitanium dioxide nanoparticles to the acrylic resin denture basematerial comparative study with the conventional and highimpact typesrdquo Oral Health and Dental Management vol 13 pp107ndash112 2014

[14] E E Totu C M Cristache E Voicila et al ldquoOn physicaland chemical characteristics of Poly(methylmethacrylate) na-nocomposites for dental applications IrdquoMateriale Plastice vol54 no 4 pp 666ndash672 2017

[15] S Shirkavand and EMoslehifard ldquoEffect of TiO2 nanoparticleson tensile strength of dental acrylic resinsrdquo Journal of DentalResearch Dental Clinics Dental Prospects vol 8 no 4 pp 197ndash203 2014

[16] M Karci N Demir and S Yazman ldquoEvaluation of FlexuralStrength of Different Denture Base Materials Reinforced withDifferent Nanoparticlesrdquo Journal of Prosthodontics 2018

[17] O Gurbuz F Unalan and I Dikbas ldquoComparison of thetransverse strength of six acrylic denture resinsrdquo OhdmbscMagazines vol 9 pp 21ndash24 2010

[18] S A Alwan and S S Alameer ldquoThe Effect of the Addition ofSilanized Nano Titania Fillers on Some Physical and Mechan-ical Properties of Heat Cured Acrylic Denture Base MaterialsrdquoJournal of Baghdad College of Dentistry vol 27 no 1 pp 86ndash912015

[19] M Ashour Ahmed M El-Shennawy Y M Althomali andA A Omar ldquoEffect of Titanium Dioxide Nano Particles In-corporation on Mechanical and Physical Properties on TwoDifferent Types of Acrylic Resin Denture Baserdquo World Journalof Nanoscience and Engineering vol 06 no 03 pp 111ndash119 2016

[20] A Sodagar S Khalil M Z Kassaee A S Shahroudi B Pourak-bari and A Bahador ldquoAntimicrobial properties of poly (methylmethacrylate) acrylic resins incorporated with silicon dioxideand titanium dioxide nanoparticles on cariogenic bacteriardquoJournal of Orthodontic Science vol 5 no 1 pp 7ndash13 2016

[21] M A Ahmed A A Omar M El-Shennawy M I Ebrahimand Y M Althomali ldquoInfluence of addition of different types ofnano-fillers on the microstructure and mechanical propertiesof PMMA based denture resinrdquo Kasmera Journal vol 45 pp48ndash59 2017

[22] MHashemM F Al Rez H Fouad et al ldquoInfluence of titaniumoxide nanoparticles on the physical and thermomechanicalbehavior of poly methyl methacrylate (pmma) A denture baseresinrdquo Science of Advanced Materials vol 9 no 6 pp 938ndash9442017

[23] L Ghahremani S Shirkavand F Akbari and N SabzikarildquoTensile strength and impact strength of color modified acrylicresin reinforcedwith titaniumdioxide nanoparticlesrdquo Journal ofClinical and Experimental Dentistry vol 9 no 5 pp e661ndashe6652017

[24] E E Totu A C Nechifor G Nechifor H Y Aboul-Eneinand C M Cristache ldquoPoly(methyl methacrylate) with TiO2nanoparticles inclusion for stereolitographic complete denturemanufacturing minus the fututre in dental care for elderly edentu-lous patientsrdquo Journal of Dentistry vol 59 pp 68ndash77 2017

[25] H K Aziz ldquoTiO-Nanofillers Effects on Some Properties ofHighly- Impact Resin Using Different Processing TechniquesrdquoThe Open Dentistry Journal vol 12 no 1 pp 202ndash212 2018

[26] M Tsuji T Ueda K Sawaki M Kawaguchi and K SakuraildquoBiocompatibility of a titanium dioxide-coating method fordenture base acrylic resinrdquo Gerodontology vol 33 no 4 pp539ndash544 2016

[27] S PodzimekM Tomka P Sommerova Y Lyuya-Mi J Bartovaand J Prochazkova ldquoImmune markers in oral discomfortpatients before and after elimination of oral galvanismrdquo Neu-roendocrinology Letters vol 34 no 8 pp 802ndash808 2013

[28] S Kiat-amnuayM Beerbower JM Powers andRD ParavinaldquoInfluence of pigments and opacifiers on color stability of

14 International Journal of Biomaterials

siliconemaxillofacial elastomerrdquo Journal ofDentistry vol 37 no1 pp e45ndashe50 2009

[29] S H Tuna F Keyf H O Gumus and C Uzun ldquoThe evaluationof water sorptionsolubility of various acrylic resinsrdquo EuropeanJournal of Dental Education vol 2 pp 191ndash197 2008

[30] S M Khaled R Sui P A Charpentier and A S RizkallaldquoSynthesis of TiO

2-PMMA nanocomposite using methacrylic

acid as a coupling agentrdquo Langmuir vol 23 no 7 pp 3988ndash39952007

[31] L Reijnders ldquoThe release of TiO2 and SiO2 nanoparticles fromnanocompositesrdquo Polymer Degradation and Stability vol 94no 5 pp 873ndash876 2009

[32] G Nazirkar S Bhanushali S Singh B Pattanaik and N RajldquoEffect of Anatase Titanium Dioxide Nanoparticles on theFlexural Strength of Heat Cured Poly Methyl MethacrylateResins An In-Vitro Studyrdquo Journal of Indian ProsthodontistSociety vol 14 pp 144ndash149 2014

[33] A Chatterjee ldquoEffect of nanoTiO2addition on poly(methyl

methacrylate) an exciting nanocompositerdquo Journal of AppliedPolymer Science vol 116 no 6 pp 3396ndash3407 2010

[34] S Rashahmadi R Hasanzadeh and S Mosalman ldquoImprov-ing the Mechanical Properties of Poly Methyl MethacrylateNanocomposites for Dentistry Applications Reinforced withDifferent Nanoparticlesrdquo PolymermdashPlastics Technology andEngineering vol 56 no 16 pp 1730ndash1740 2017

[35] A H Yuwono B Liu J Xue et al ldquoControlling the crystallinityand nonlinear optical properties of transparent TiO

2-PMMA

nanohybridsrdquo Journal of Materials Chemistry vol 14 no 20 pp2978ndash2987 2004

[36] J K Pandey K RaghunathaReddy A P Kumar andR P SinghldquoAn overviewon the degradability of polymer nanocompositesrdquoPolymer Degradation and Stability vol 88 no 2 pp 234ndash2502005

[37] C Tao S Jianping J Weng L Ting and H Xiaozhu ldquoPrepara-tion and properties of PMMATiO2 nanocompositerdquoChemicalReaction Engineering andTechnology vol 23 pp 435ndash440 2007

[38] A H Yuwono J Xue J Wang et al ldquoTransparent nanohybridsof nanocrystalline TiO2 in PMMA with unique nonlinearoptical behaviorrdquo Journal of Materials Chemistry vol 13 no 6pp 1475ndash1479 2003

[39] R Alla K N Raghavendra R Vyas and A KonakanchildquoConventional and contemporary polymers for the fabricationof denture prosthesis Part I overview composition and proper-tiesrdquo International Journal of Applied Dental Sciences vol 1 noPart I pp 82ndash89 2015

[40] C C Trapalis P Keivanidis G Kordas et al ldquoTiO2(Fe3+)nanostructured thin films with antibacterial propertiesrdquo ThinSolid Films vol 433 no 1-2 pp 186ndash190 2003

[41] L S Acosta-Torres L M Lopez-Marın R E Nunez-Anita GHernandez-Padron and V M Castano ldquoBiocompatible Metal-Oxide Nanoparticles Nanotechnology Improvement of Con-ventional Prosthetic Acrylic Resinsrdquo Journal of Nanomaterialsvol 2011 Article ID 941561 8 pages 2011

[42] A Bahador S Khalil B Pourakbari et al ldquoPhotocatalyticEffects of Acrylic Resins Incorporated with Nano-titaniumDioxide on Planktonic and Biofilm Growth of Four CariogenicBacteriardquo Annual Research amp Review in Biology vol 4 no 17pp 2695ndash2708 2014

[43] A Alrahlah H Fouad M Hashem A Niazy and A AlBadahldquoTitanium Oxide (TiO2)Polymethylmethacrylate (PMMA)Denture Base Nanocomposites Mechanical Viscoelastic and

Antibacterial BehaviorrdquoMaterials vol 11 no 7 Article ID 1096pp 10961ndash109615 2018

[44] A Kubacka M Ferrer M L Cerrada et al ldquoBoostingTiO2-anatase antimicrobial activity Polymer-oxide thin filmsrdquoApplied Catalysis B Environmental vol 89 no 3-4 pp 441ndash4472009

[45] Y Cheng T Sakai R Moroi et al ldquoSelf-cleaning abilityof a photocatalyst-containing denture base materialrdquo DentalMaterials vol 27 no 2 pp 179ndash186 2008

[46] C M Bollen P Lambrechts and M Quirynen ldquoComparisonof surface roughness of oral hard materials to the thresholdsurface roughness for bacterial plaque retention a review of theliteraturerdquoDental Materials vol 13 no 4 pp 258ndash269 1997

[47] N Elshereksi M Ghazali A Muchtar and C Azhari ldquoEffectof nanobarium titanate addition on the surface characteristicsof denture base resinrdquo International Journal of Mechanical andProduction Engineering vol 5 pp 1ndash8 2017

[48] Y Xia Z Feimin H Xie and N Gu ldquoNanoparticles reinforcedresin based dental compositesrdquo Journal of Dentistry vol 36 pp450ndash455 2008

[49] S Mosalman S Rashahmadi and R Hasanzadeh ldquoThe effectof TiO2 nanoparticles on mechanical properties of poly methylmethacrylate nanocompositesrdquo International Journal of Engi-neering Transactions B Applications vol 30 no 5 pp 807ndash8132017

[50] Y Han S Kiat-amnuay J M Powers and Y Zhao ldquoEffectof nano-oxide concentration on the mechanical properties ofa maxillofacial silicone elastomerrdquo The Journal of ProstheticDentistry vol 100 no 6 pp 465ndash473 2008

[51] I N Safi ldquoEvaluation the effect of nanomdashfillers (TiO2 AL2O3

SiO2) addition on glass transition temperature E-moudulus

and coefficient of thermal expansion of acrylic denture basematerialrdquo Journal of Baghdad College of Dentistry vol 26 no1 pp 37ndash41 2014

[52] W Wang S Liao Y Zhu M Liu Q Zhao and Y Fu ldquoRecentApplications of Nanomaterials in Prosthodonticsrdquo Journal ofNanomaterials vol 2015 Article ID 408643 11 pages 2015

[53] L Sun R F Gibson F Gordaninejad and J Suhr ldquoEnergyabsorption capability of nanocomposites A reviewrdquoCompositesScience and Technology vol 69 no 14 pp 2392ndash2409 2009

[54] S Podzimek K Hana M Miksovsky et al ldquoThe Influence ofgalvanic currents and voltage on the proliferation activity oflymphocytes and expression of cell surface moleculesrdquo FoliaBiologica vol 54 no 5 pp 146ndash150 2008

[55] E E Totu E Voicila V Pistritu G Nechifor and C MCristache ldquoEvaluation of electrical characteristics for PMMA-TiO2 nanocomposites used in dentistryrdquo Evista de Chimie vol69 no 1 pp 155ndash159 2018

CorrosionInternational Journal of

Hindawiwwwhindawicom Volume 2018

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Materials Science and EngineeringHindawiwwwhindawicom Volume 2018

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Chemistry

Analytical ChemistryInternational Journal of

Hindawiwwwhindawicom Volume 2018

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Hindawiwwwhindawicom Volume 2018

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Advances in Condensed Matter Physics

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International Journal of

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TribologyAdvances in

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Journal of

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Journal ofNanomaterials

Submit your manuscripts atwwwhindawicom

International Journal of Biomaterials 7

2 Overall Performanceand Clinical Significance

It is well understood that advancements in biomaterialscience affect the progression of technologies in any fieldincluding dental prostheses The introduction of nanomate-rials had significantly changed the clinical and technolog-ical aspects of dentistry In this paper the latest researchprogress on the applications of TiO

2NP in prosthodontics

was reviewed It clearly shows varying responses of phys-ical and mechanical properties of the modified materialswhere a number of properties improved others deterio-rated and few did not change Their level of effectivenessas shown in the literature is diverse being more or lesseffective than pure materials Therefore to attain removableprostheses with improved properties and acceptable clinicalperformance the material of manufacture (acrylic resin)can be enhanced by adding proper percentage of nanofillerinitial surface treatment of the nanoparticles and appro-priate selection of addition method Authors hope that thisreview article would provide some valuable elicitation forfuture scientific and technological innovations in the relatedfield

Based on this review TiO2NPwere found to be enhancers

in some aspects modifiers in some and insignificant in oth-ers The effect depends mainly on NP size addition methodsurface treatment and loading percentage Although the sizeof NP ranged between 5 nm and 350 nm the results of thestudies were not justified based on the nanofiller size anda clear link between size and effect was not established Forthat further investigations to relate the resulting propertiesto nanoparticle size are required

Variations in the results were mainly related to fillermode of addition The addition of nanoparticles to acrylicmonomer was considered more effective owing to betterdispersion of NP within the monomer In this method thedominant improvement was noticed in mechanical prop-erties while physical properties were slightly affected It isworth noting that with this technique the polymer monomerratio may be affected Therefore mixing the nanofillerwith acrylic powder has been suggested and studied Tillnow no study can be found that compares between theeffects of different modes of addition (nanofillers additionto powder or monomer) Based on this review furtherinvestigations of the above-mentioned point are necessaryas well as the proper way to establish the proportion ofpolymermonomer ratio for each method hence nanofilleraddition interferes with the manufacturersquos recommendedratios

The percentage of addition also plays a role in resultingproperties While the range of addition was very broad(05ndash30wt) low percentages resulted in improved prop-erties compared to higher percentages Simple addition of1ndash2wt ratios exhibited improved properties while increas-ing the filler content more than 5wt significantly weakenedthe final nanocomposites In fact the bonding betweenTiO2NP and resin matrix is a critical factor to achieve the

desired properties of nanocomposite As showed in Table 1the treatment of NPwith saline coupling agents improved the

properties in comparison to untreated particles ThereforeNP surface treatment is recommended

According to Table 1 inconsistencies in prepared spec-imen sizes for the same test were seen which may havecontributed to variations in the results between studiesexperimenting with the same filler percentage This reflectsa major error in the methodologies of the studies where thetest should have been done according to standardized spec-imensrsquo dimensions and testing procedures Testing shouldfollow an internationally accepted standardization proto-col like the ADA specifications for denture base polymersto make it possible to compare results between differentstudies

Titanium nanoparticles remain under focus because ofthe antimicrobial efficacy against candida species despitetheir negative effect on a number of properties Incorporationof TiO

2NP into PMMA matrix proved to have antimicrobial

effects specifically on candida species [24] Not to be lost inthis discussion is the effect of TiO

2NP surface modification

on antimicrobial properties of the final product It was shownthat modification with noble metals such as (Ag Au Ptand Pd) on TiO

2NP surface enhanced the photocatalytic

ability of the nanoparticles and bactericidal activity thereafter[12]

Even with this number of studies on recently introducedTiO2NP into PMMA no clear evidence on the clinical

applicability of this nanocomposite has been demonstratedFurther investigations are required to interpret and confirmthe chemical structure changes in PMMATiO

2nanocom-

posite and also to determine the need from otherwise forsurface treatment as well as the proper percentage of additionthat will not affect the final product adversely

Research to improve upon existing nanomaterials is stillongoing with emphasis on efficiency Although the sciencebehind nanotechnology is intriguing the lack of long-termevidence addressing their clinical performance restricts theirwide clinical use Overall there is an essential requirement toinvestigate the durability of these PMMATiO

2composites in

different environmental conditions to extend the applicabilityof these hybrid materials

3 Conclusion

Based on the current review we could conclude thatthe addition of TiO

2NP to PMMA denture bases is still

questionable for working as a reinforcing material andrequires further investigations following the ADA specifica-tions These investigations must explore the chemical andstructural changes happening in the nanocomposite afterTiO2addition The improvements in properties mentioned

above were dominantly seen with lower concentrations ofTiO2and the increase in the amount of added nanopar-

ticles caused adverse effects on resulting PMMATiO2

compositeIn conclusion there is an essential need to investigate the

clinical performance and durability of these nanocompositesin different conditions simulating the oral environment toverify their applicability and provide an insight of possiblefuture researches in this field

8 International Journal of Biomaterials

Table1TiO2NPapplications

indentureb

asea

ndits

effecto

nthetestedprop

ertie

s

Authorsyear

Particlesiz

eAd

ditio

npercentage

Type

ofAc

rylic

Nanocom

positep

reparatio

nProp

ertie

stested

Specim

ensiz

eEff

ects

(IncreaseD

ecreaseUnchanged)

Chatterje

e2010

[9]

5nm

0-15w

tPM

MAfro

mScientificP

olym

erProd

ucts(O

ntario

NY)

(i)MeasuredTiO2NPmixed

with

PMMAfor5

-10min

(ii)D

ACAtwin-screw

extractio

nprocessa

t190∘C

and100rpm

(iii)Ac

rylic

mixed

for6

-7min

andextrud

ed5tim

es

(i)Tensile

mod

ulus

(ii)D

imensio

nal

stability

(iii)Glasstransition

temperature(T

g)

(iv)U

Vabsorptio

n

10x6x03m

m

5mg

(i)Im

provem

entintensile

mod

ulus

(ii)Increased

thermalsta

bility

(iii)IncreasedT g

(iv)Improvem

entinUV

absorptio

n997888rarr

maxim

umat2

TiO2NP

Chatterje

e2010

[10]

5nm

0 20

50 75

100

150

300

PMMAfro

mScientificP

olym

erProd

ucts(O

ntario

NY)

(i)MeasuredTiO2NPmixed

with

PMMAfor5

-10min

(ii)D

ACAtwin-screw

extractio

nprocessa

t190∘C

and100rpm

(iii)Ac

rylic

mixed

for6

-7min

andextrud

ed5tim

es

(i)Glasstransition

temperature(T

g)

(ii)Th

ermalsta

bility

(iii)Decom

position

temperature

10x6x03m

m

(i)T g

increasedlin

early

upto

75TiO2NP

(ii)Th

ermalsta

bilityincreased

(2-15

TiO2NP)

(iii)Decom

position

temperaturesincreased

with

filler

contentu

pto

10TiO2NP

Aneho

suretal

2012

[11]

31nm

ldquoAnataseph

aserdquo

30

Inadditio

nto

surfa

cecoating

DPI

heatcure

acrylic

resin

(In

dia)

(i)Visib

lelig

htactiv

ated

TiO2NPwe

remixed

with

methylm

ethacrylate

mon

omer

(i)Microbial

inhibitory

effect

againstSA

ureus

5x5x2mm

(i)3w

of

TiO2show

santim

icrobialactiv

ityagainstS

Au

reus

Sodagare

tal2013

[12]

21nm

ldquoAnatase

phaserdquo

0 05 10

SelectaP

lus

(self-c

urea

crylic

resin

)

(i)TiO2NPwe

readdedto

acrylic

mon

omer

(i)Flexuralstr

ength

50x10

x33m

m(i)

Flexuralstr

engthdecreasedas

thefi

llerc

ontent

increased

(i)Flexuralmod

ulus

(i)Nochange

inflexu

ral

mod

ulus

Ham

ouda

and

Beyari

2014

[13]

21nm

50

Con

ventionalh

eat

cure

acrylic

resin

(AcrostonWHN

England)

andhigh

impact(M

etrocryl

HiMetrodent

LTDE

ngland

)

(i)TiO2NPwe

remixed

thorou

ghlywith

acrylic

powd

erby

hand

(ii)F

lexu

ral

strength

(iii)To

ughn

ess

65x10

x25mm

(ii)F

lexu

ralstre

ngth

and

toug

hnessd

ecreased

(iv)M

onom

errelease

(iii)Nodifferenceb

etwe

encontroland

TiO2reinforced

regardingmon

omer

release

International Journal of Biomaterials 9

Table1Con

tinued

Authorsyear

Particlesiz

eAd

ditio

npercentage

Type

ofAc

rylic

Nanocom

positep

reparatio

nProp

ertie

stested

Specim

ensiz

eEff

ects

(IncreaseD

ecreaseUnchanged)

Nazirk

aretal

2014

[14]

7nm

ldquoAnatase

phaserdquo

0 05 10

DPI

heatcure

acrylic

resin

(i)TiO2NPaddedto

acrylic

mon

omer

(i)Flexuralstr

ength

65x10

x33mm

(i)Flexuralstr

engthdecreasedas

theT

iO2am

ount

increased

Shirk

avandand

Moslehifard2014

[15]

lt25

nm(averagesim204

nm)

ldquoAnataseand

Rutilep

hasesrdquo

0 05 10

20

Heatcurea

crylic

resin

from

Ivoclar

Vivadent

(i)TiO2NPwe

remixed

with

thea

crylicresin

polymer

inan

amalgamator

for2

0min

(i)Tensile

strength

60x12

x4mm

(i)Tensile

strengthandelastic

mod

ulus

improved

with

1TiO2NP

(ii)0

5and2

TiO2we

reno

tsig

nificantly

different

from

each

othero

rcon

trol

Harinietal2014

[16]

0 10

20

50

Clearh

eatcure

acrylic

resin

(i)Nanop

artic

lesw

ere

incorporated

into

mon

omer

byultrason

icdispersio

n(i)

Flexuralstr

ength

65x10

x3mm

(i)Flexuralstr

engthim

proved

with

TiO2additio

nsig

nificant

differencen

oticed

with

5

Safi2014

[17]

50

Heatcured

enture

base

acrylic

(Sup

eracrylplus

Czecho

slovakia)

(i)Nanop

artic

lesa

dded

tomon

omer

andsonically

dispersed

(i)Coefficientof

thermalexpansion

(ii)M

odulus

(iii)Glasstransition

15x6mm

Cylin

ders

65x10

x25mm

Powd

erform

(10g)

(i)Decreaseincoeffi

cientof

thermalexpansion

(ii)D

ecreased

inmod

ulus

ofelastic

ity

(iii)IncreasedT g

Alwanand

Alameer2015

[18]

lt50

nmsiz

e0 30

(i)Silanizedwith

TMSP

M

Heatcurea

crylic

resin

(i)SilanizedTiO2NPwe

readdedto

mon

omer

and

sonicated

(i)Im

pactstr

ength

(ii)T

ransverse

strength

(iii)Hardn

ess

(iv)S

urface

roug

hness

(v)W

atersorptio

nandsolubility

80x10

x4mm

65x10x25m

m

50x05m

mdisc

(i)Increased

(ii)Increased

(iii)Increased

(iv)Increased

(v)D

ecreased

10 International Journal of Biomaterials

Table1Con

tinued

Authorsyear

Particlesiz

eAd

ditio

npercentage

Type

ofAc

rylic

Nanocom

positep

reparatio

nProp

ertie

stested

Specim

ensiz

eEff

ects

(IncreaseD

ecreaseUnchanged)

Ahm

edetal2016

[19]

46nm

0 10

50

Con

ventionalh

eat

cure

acrylic

resin

(ImplacrylVe

rtex)

andhigh

impact

heatcureacrylic

resin

(Vertex-Dental

Netherla

nds)

(i)TiO2NPwe

readdedinto

acrylic

resin

(i)Flexuralstr

ength

(ii)Impactstr

ength

(iii)Hardn

ess

50x10

x3mm

60x6x4mm

25x10

x3mm

(i)Decreased

with

TiO2

additio

n

(ii)Increased

onlyfor

conventio

nalacrylicresin

mod

ified

by1

(iii)Increasedwith

5additio

nTiO2NPforb

othtypeso

facrylic

Sodagare

tal2016

[20]

21nm

05 10

SelectaP

lus

(self-c

urea

crylic

resin

)

(i)Nanop

artic

lesw

erea

dded

toacrylic

mon

omer

and

stirred

(i)Antim

icrobial

prop

ertie

s20

x20

x1m

m

(i)TiO2redu

cedmicrobial

grow

thatbo

thconcentrations

at90

min

underU

VAexpo

sure

(ii)A

ntim

icrobialactiv

ityof

TiO2istim

edependent

Ahm

edetal2017

[21]

lt25

nm0 05 10

Heatcurea

crylic

resin

from

Dentsp

lyInternationalInc

(ChicagoIL

USA

)

(i)TiO2NPwe

readdedto

acrylic

polymer

andmixed

usingam

algam

capsule

(i)Flexuralstr

ength

(ii)F

racture

toug

hness

(iii)Hardn

ess

65x10

x25mm

65x10

x25mm

30x10

x25mm

(i)Increasedwith

both

filler

percentages

(ii)N

oeffecto

nfracture

toug

hnesso

fbothfiller

percentages

(iii)Increasedwith

1filler

Hashem

etal2

017

[22]

90nm

0 10

20 30

Self-cureacrylic

resin

from

Eco-crylcold

Protechn

o(Spain)

(i)TiO2NPwe

remixed

with

them

onom

er

(i)Flexuralmod

ulus

andflexu

ral

strength

(ii)H

ardn

ess

(iii)Surfa

cewe

tting

30x8x1m

m

50x1m

mdiscs

(i)Increasedlin

early

(ii)Increased

(iii)Re

ducedwith

1filler

contentand

increasedwith

high

erpercentages

(iv)T

gdecreasedwith

TiO2

additio

n

Ghahrem

anietal

2017

[23]

20-30nm

ldquoAnatase

phaserdquo

0 10

SRTriplexHot

heatcureacrylic

resin

(Ivoclar

Vivadent

Inc

Schaan

Liechtenste

in)

(i)TiO2NPwe

remixed

with

acrylic

resin

powd

erin

anultrason

icmixer

(i)Tensile

strength

(ii)Impactstr

ength

60x12

x39mm

75x10

x10

mm

(i)Increased

(ii)Increased

International Journal of Biomaterials 11Ta

ble1Con

tinued

Authorsyear

Particlesiz

eAd

ditio

npercentage

Type

ofAc

rylic

Nanocom

positep

reparatio

nProp

ertie

stested

Specim

ensiz

eEff

ects

(IncreaseD

ecreaseUnchanged)

Totu

etal2017

[24]

65-170

nm

0 02

04 1 25

PMMA+P

EMAfor

3Dprintin

g(eDent

100En

visio

nTec

GmbH

Gladb

eck

Germany)

(i)Nanop

artic

lesw

erea

dded

into

PMMAsolutio

nwith

continuo

usstirringand

ultrason

icmixingfor1

hour

(i)Antim

icrobial

effect(Ca

ndida

scotti)

(ii)C

omplete

denture

manufacturin

gusin

gste

reolith

ograph

y

(i)041

and25

inhibited

cand

idagrow

th

(ii)P

MMA04TiO2compo

site

successfu

llyused

ford

enture

fabrication

Aziz2018

[25]

30nm

0 30

Highim

pactheat

cure

acrylic

resin

(Vertex-Dental

Netherla

nds)-

(i)TiO2NPwe

redispersedin

mon

omer

andsonicatedat

120W

and60

KHzfor

3minutes

(i)Im

pactstr

ength

(ii)C

olor

stability

(iii)Th

ermal

cond

uctiv

ity

80x10

x4mm

35x15

x05mm

40x25mm

(i)Increased

(ii)Increased

colorstabilityfor

testgrou

ps

(iii)Noeffect

Alra

hlah

etal

2018

[26]

80-100

nm

0 1 2 3

Heatcurea

crylic

resin

(Lucito

ne550Dentsp

lyInt

IncPaU

SA)

(i)Hardn

essa

ndmod

ulus

(ii)T

gdegradation

temperatureand

rate

(iii)Cr

eep-recovery

andrelaxatio

nbehavior

(iv)A

ntibacteria

ladhesio

n

50x10

mm

discs

cutindifferent

sizes

ford

ifferent

tests

7mg

5x10

mm

(i)Increased

(ii)S

light

increase

with

2nano

-fillerc

ontent

(iii)Im

provem

entinbehavior

(iv)D

ecreaseinbacterial

attachmentcon

tent

Karcietal2018

[27]

13nm

0 1 3 5

(i)Au

to-polyeriz

ed(H

eraeus

Kulze

rNew

bury

Berkshire

UK)

(ii)

Heat-p

olym

erized

Heraeus

Kulze

rNew

bury

Berkshire

UK

(iii)Microwave-

polymerized

(GC

DentalTo

kyo

Japan)

(i)TiO2NPwe

remixed

with

acrylic

resin

powd

erusing

ballmillingat40

0rpm

for2

hours

(i)Flexuralstr

ength

65x10

x3mm

(i)Increasedforh

eat-and

auto-polym

erized

acrylic

at1

(ii)D

ecreased

fora

lltypeso

facrylic

at5

12 International Journal of Biomaterials

Table1Con

tinued

Authorsyear

Particlesiz

eAd

ditio

npercentage

Type

ofAc

rylic

Nanocom

positep

reparatio

nProp

ertie

stested

Specim

ensiz

eEff

ects

(IncreaseD

ecreaseUnchanged)

Totu

etalTo

tuet

al2

017[28]

ldquoAnatase

phaserdquo

0 02

04

06 10

25

(i)PM

MA-

MA

(ii)P

MMA-

MMA-

BPO

(iii)3D

printed

PMMA(eD

Envisio

nTec

GmbH

Gladb

eck

Germany)

(i)TiO2mod

ified

bymethacrylicacid

then

manually

mixed

with

PMMAmixture

(i)Th

ermalsta

bility

(ii)T

g

Stereolitho

graphic

dentures

(i)Increased(im

proved)

(ii)Increased

Totu

etal2018

[29]

ldquoAnatase

phaserdquo

0 02

04

06 10

20 25 50

PMMAfor3

Dprintin

g(eDent

100En

visio

nTec

GmbH

Gladb

eck

Germany)

(i)Re

sistance

(ii)E

lectric

alcond

uctiv

ity

(iii)Dielectric

constant

(i)Decreased

with

1020

25

and5

(ii)Increased

butm

aterialstill

maintainedinsulatin

gprop

ertie

s

(iii)Increasedwith

5

International Journal of Biomaterials 13

Conflicts of Interest

The authors declare that they have no conflicts of interest

References

[1] R L Sakaguchi and J M Powers Craigrsquos Restorative DentalMaterials Elsevier Health Sciences Philadelphia PA USA pp163-176 2012

[2] N Murakami N Wakabayashi R Matsushima A Kishidaand Y Igarashi ldquoEffect of high-pressure polymerization onmechanical properties of PMMA denture base resinrdquo Journalof the Mechanical Behavior of Biomedical Materials vol 20 pp98ndash104 2013

[3] R Adhikari and G H Michler ldquoPolymer nanocompositescharacterization by microscopyrdquo Polymer Reviews vol 49 no3 pp 141ndash180 2009

[4] A Navidfar T Azdast and A Karimzad Ghavidel ldquoInfluenceof processing condition and carbon nanotube on mechani-cal properties of injection molded multi-walled carbon nan-otubepoly(methyl methacrylate) nanocompositesrdquo Journal ofApplied Polymer Science vol 133 no 31 Article ID 43738 pp1ndash9 2016

[5] P Chaijareenont H Takahashi N Nishiyama and M Ark-sornnukit ldquoEffect of different amounts of 3-methacryloxypro-pyltrimethoxysilane on the flexural properties and wear resis-tance of alumina reinforced PMMArdquo Dental Materials vol 31no 4 pp 623ndash628 2012

[6] J Jordan K I Jacob R TannenbaumMA Sharaf and I JasiukldquoExperimental trends in polymer nanocompositesmdasha reviewrdquoMaterials Science and Engineering A vol 393 no 1-2 pp 1ndash112005

[7] MMGad SM Fouda F A Al-Harbi RNapankangas andARaustia ldquoPMMAdenture base material enhancement A reviewof fiber filler and nanofiller additionrdquo International Journal ofNanomedicine vol 12 pp 3801ndash3812 2017

[8] F Li S Zhou B You and L Wu ldquoKinetic study onthe UV-induced photopolymerization of epoxy acrylateTiO2nanocomposites by FTIR spectroscopyrdquo Journal of AppliedPolymer Science vol 99 no 6 pp 3281ndash3287 2006

[9] A Chatterjee ldquoProperties improvement of PMMA using nanoTiO2rdquo Journal of Applied Polymer Science vol 118 no 5 pp2890ndash2897 2010

[10] P Harini K Mohamed and T V Padmanabhan ldquoEffect ofTitanium dioxide nanoparticles on the flexural strength ofpolymethylmethacrylate An in vitro studyrdquo Indian Journal ofDental Research vol 25 no 4 pp 459ndash463 2014

[11] G Venkatesh Anehosur R D Kulkarni M G Naik et alldquoSynthesis and Determination of Antimicrobial Activity ofVisible Light Activated TiO2 Nanoparticles with PolymethylMethacrylate Denture Base Resin Against StaphylococcusAureusrdquo Journal of Gerontology ampGeriatric Research vol 01 no01 pp 103ndash111 2012

[12] A Sodagar A Bahador S Khalil A Saffar Shahroudi and MZaman Kassaee ldquoThe effect of TiO

2and SiO

2nanoparticles on

flexural strength of poly (methyl methacrylate) acrylic resinsrdquoJournal of Prosthodontic Research vol 57 no 1 pp 15ndash19 2013

[13] I M Hamouda and M M Beyari ldquoAddition of glass fibers andtitanium dioxide nanoparticles to the acrylic resin denture basematerial comparative study with the conventional and highimpact typesrdquo Oral Health and Dental Management vol 13 pp107ndash112 2014

[14] E E Totu C M Cristache E Voicila et al ldquoOn physicaland chemical characteristics of Poly(methylmethacrylate) na-nocomposites for dental applications IrdquoMateriale Plastice vol54 no 4 pp 666ndash672 2017

[15] S Shirkavand and EMoslehifard ldquoEffect of TiO2 nanoparticleson tensile strength of dental acrylic resinsrdquo Journal of DentalResearch Dental Clinics Dental Prospects vol 8 no 4 pp 197ndash203 2014

[16] M Karci N Demir and S Yazman ldquoEvaluation of FlexuralStrength of Different Denture Base Materials Reinforced withDifferent Nanoparticlesrdquo Journal of Prosthodontics 2018

[17] O Gurbuz F Unalan and I Dikbas ldquoComparison of thetransverse strength of six acrylic denture resinsrdquo OhdmbscMagazines vol 9 pp 21ndash24 2010

[18] S A Alwan and S S Alameer ldquoThe Effect of the Addition ofSilanized Nano Titania Fillers on Some Physical and Mechan-ical Properties of Heat Cured Acrylic Denture Base MaterialsrdquoJournal of Baghdad College of Dentistry vol 27 no 1 pp 86ndash912015

[19] M Ashour Ahmed M El-Shennawy Y M Althomali andA A Omar ldquoEffect of Titanium Dioxide Nano Particles In-corporation on Mechanical and Physical Properties on TwoDifferent Types of Acrylic Resin Denture Baserdquo World Journalof Nanoscience and Engineering vol 06 no 03 pp 111ndash119 2016

[20] A Sodagar S Khalil M Z Kassaee A S Shahroudi B Pourak-bari and A Bahador ldquoAntimicrobial properties of poly (methylmethacrylate) acrylic resins incorporated with silicon dioxideand titanium dioxide nanoparticles on cariogenic bacteriardquoJournal of Orthodontic Science vol 5 no 1 pp 7ndash13 2016

[21] M A Ahmed A A Omar M El-Shennawy M I Ebrahimand Y M Althomali ldquoInfluence of addition of different types ofnano-fillers on the microstructure and mechanical propertiesof PMMA based denture resinrdquo Kasmera Journal vol 45 pp48ndash59 2017

[22] MHashemM F Al Rez H Fouad et al ldquoInfluence of titaniumoxide nanoparticles on the physical and thermomechanicalbehavior of poly methyl methacrylate (pmma) A denture baseresinrdquo Science of Advanced Materials vol 9 no 6 pp 938ndash9442017

[23] L Ghahremani S Shirkavand F Akbari and N SabzikarildquoTensile strength and impact strength of color modified acrylicresin reinforcedwith titaniumdioxide nanoparticlesrdquo Journal ofClinical and Experimental Dentistry vol 9 no 5 pp e661ndashe6652017

[24] E E Totu A C Nechifor G Nechifor H Y Aboul-Eneinand C M Cristache ldquoPoly(methyl methacrylate) with TiO2nanoparticles inclusion for stereolitographic complete denturemanufacturing minus the fututre in dental care for elderly edentu-lous patientsrdquo Journal of Dentistry vol 59 pp 68ndash77 2017

[25] H K Aziz ldquoTiO-Nanofillers Effects on Some Properties ofHighly- Impact Resin Using Different Processing TechniquesrdquoThe Open Dentistry Journal vol 12 no 1 pp 202ndash212 2018

[26] M Tsuji T Ueda K Sawaki M Kawaguchi and K SakuraildquoBiocompatibility of a titanium dioxide-coating method fordenture base acrylic resinrdquo Gerodontology vol 33 no 4 pp539ndash544 2016

[27] S PodzimekM Tomka P Sommerova Y Lyuya-Mi J Bartovaand J Prochazkova ldquoImmune markers in oral discomfortpatients before and after elimination of oral galvanismrdquo Neu-roendocrinology Letters vol 34 no 8 pp 802ndash808 2013

[28] S Kiat-amnuayM Beerbower JM Powers andRD ParavinaldquoInfluence of pigments and opacifiers on color stability of

14 International Journal of Biomaterials

siliconemaxillofacial elastomerrdquo Journal ofDentistry vol 37 no1 pp e45ndashe50 2009

[29] S H Tuna F Keyf H O Gumus and C Uzun ldquoThe evaluationof water sorptionsolubility of various acrylic resinsrdquo EuropeanJournal of Dental Education vol 2 pp 191ndash197 2008

[30] S M Khaled R Sui P A Charpentier and A S RizkallaldquoSynthesis of TiO

2-PMMA nanocomposite using methacrylic

acid as a coupling agentrdquo Langmuir vol 23 no 7 pp 3988ndash39952007

[31] L Reijnders ldquoThe release of TiO2 and SiO2 nanoparticles fromnanocompositesrdquo Polymer Degradation and Stability vol 94no 5 pp 873ndash876 2009

[32] G Nazirkar S Bhanushali S Singh B Pattanaik and N RajldquoEffect of Anatase Titanium Dioxide Nanoparticles on theFlexural Strength of Heat Cured Poly Methyl MethacrylateResins An In-Vitro Studyrdquo Journal of Indian ProsthodontistSociety vol 14 pp 144ndash149 2014

[33] A Chatterjee ldquoEffect of nanoTiO2addition on poly(methyl

methacrylate) an exciting nanocompositerdquo Journal of AppliedPolymer Science vol 116 no 6 pp 3396ndash3407 2010

[34] S Rashahmadi R Hasanzadeh and S Mosalman ldquoImprov-ing the Mechanical Properties of Poly Methyl MethacrylateNanocomposites for Dentistry Applications Reinforced withDifferent Nanoparticlesrdquo PolymermdashPlastics Technology andEngineering vol 56 no 16 pp 1730ndash1740 2017

[35] A H Yuwono B Liu J Xue et al ldquoControlling the crystallinityand nonlinear optical properties of transparent TiO

2-PMMA

nanohybridsrdquo Journal of Materials Chemistry vol 14 no 20 pp2978ndash2987 2004

[36] J K Pandey K RaghunathaReddy A P Kumar andR P SinghldquoAn overviewon the degradability of polymer nanocompositesrdquoPolymer Degradation and Stability vol 88 no 2 pp 234ndash2502005

[37] C Tao S Jianping J Weng L Ting and H Xiaozhu ldquoPrepara-tion and properties of PMMATiO2 nanocompositerdquoChemicalReaction Engineering andTechnology vol 23 pp 435ndash440 2007

[38] A H Yuwono J Xue J Wang et al ldquoTransparent nanohybridsof nanocrystalline TiO2 in PMMA with unique nonlinearoptical behaviorrdquo Journal of Materials Chemistry vol 13 no 6pp 1475ndash1479 2003

[39] R Alla K N Raghavendra R Vyas and A KonakanchildquoConventional and contemporary polymers for the fabricationof denture prosthesis Part I overview composition and proper-tiesrdquo International Journal of Applied Dental Sciences vol 1 noPart I pp 82ndash89 2015

[40] C C Trapalis P Keivanidis G Kordas et al ldquoTiO2(Fe3+)nanostructured thin films with antibacterial propertiesrdquo ThinSolid Films vol 433 no 1-2 pp 186ndash190 2003

[41] L S Acosta-Torres L M Lopez-Marın R E Nunez-Anita GHernandez-Padron and V M Castano ldquoBiocompatible Metal-Oxide Nanoparticles Nanotechnology Improvement of Con-ventional Prosthetic Acrylic Resinsrdquo Journal of Nanomaterialsvol 2011 Article ID 941561 8 pages 2011

[42] A Bahador S Khalil B Pourakbari et al ldquoPhotocatalyticEffects of Acrylic Resins Incorporated with Nano-titaniumDioxide on Planktonic and Biofilm Growth of Four CariogenicBacteriardquo Annual Research amp Review in Biology vol 4 no 17pp 2695ndash2708 2014

[43] A Alrahlah H Fouad M Hashem A Niazy and A AlBadahldquoTitanium Oxide (TiO2)Polymethylmethacrylate (PMMA)Denture Base Nanocomposites Mechanical Viscoelastic and

Antibacterial BehaviorrdquoMaterials vol 11 no 7 Article ID 1096pp 10961ndash109615 2018

[44] A Kubacka M Ferrer M L Cerrada et al ldquoBoostingTiO2-anatase antimicrobial activity Polymer-oxide thin filmsrdquoApplied Catalysis B Environmental vol 89 no 3-4 pp 441ndash4472009

[45] Y Cheng T Sakai R Moroi et al ldquoSelf-cleaning abilityof a photocatalyst-containing denture base materialrdquo DentalMaterials vol 27 no 2 pp 179ndash186 2008

[46] C M Bollen P Lambrechts and M Quirynen ldquoComparisonof surface roughness of oral hard materials to the thresholdsurface roughness for bacterial plaque retention a review of theliteraturerdquoDental Materials vol 13 no 4 pp 258ndash269 1997

[47] N Elshereksi M Ghazali A Muchtar and C Azhari ldquoEffectof nanobarium titanate addition on the surface characteristicsof denture base resinrdquo International Journal of Mechanical andProduction Engineering vol 5 pp 1ndash8 2017

[48] Y Xia Z Feimin H Xie and N Gu ldquoNanoparticles reinforcedresin based dental compositesrdquo Journal of Dentistry vol 36 pp450ndash455 2008

[49] S Mosalman S Rashahmadi and R Hasanzadeh ldquoThe effectof TiO2 nanoparticles on mechanical properties of poly methylmethacrylate nanocompositesrdquo International Journal of Engi-neering Transactions B Applications vol 30 no 5 pp 807ndash8132017

[50] Y Han S Kiat-amnuay J M Powers and Y Zhao ldquoEffectof nano-oxide concentration on the mechanical properties ofa maxillofacial silicone elastomerrdquo The Journal of ProstheticDentistry vol 100 no 6 pp 465ndash473 2008

[51] I N Safi ldquoEvaluation the effect of nanomdashfillers (TiO2 AL2O3

SiO2) addition on glass transition temperature E-moudulus

and coefficient of thermal expansion of acrylic denture basematerialrdquo Journal of Baghdad College of Dentistry vol 26 no1 pp 37ndash41 2014

[52] W Wang S Liao Y Zhu M Liu Q Zhao and Y Fu ldquoRecentApplications of Nanomaterials in Prosthodonticsrdquo Journal ofNanomaterials vol 2015 Article ID 408643 11 pages 2015

[53] L Sun R F Gibson F Gordaninejad and J Suhr ldquoEnergyabsorption capability of nanocomposites A reviewrdquoCompositesScience and Technology vol 69 no 14 pp 2392ndash2409 2009

[54] S Podzimek K Hana M Miksovsky et al ldquoThe Influence ofgalvanic currents and voltage on the proliferation activity oflymphocytes and expression of cell surface moleculesrdquo FoliaBiologica vol 54 no 5 pp 146ndash150 2008

[55] E E Totu E Voicila V Pistritu G Nechifor and C MCristache ldquoEvaluation of electrical characteristics for PMMA-TiO2 nanocomposites used in dentistryrdquo Evista de Chimie vol69 no 1 pp 155ndash159 2018

CorrosionInternational Journal of

Hindawiwwwhindawicom Volume 2018

Advances in

Materials Science and EngineeringHindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

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Chemistry

Analytical ChemistryInternational Journal of

Hindawiwwwhindawicom Volume 2018

ScienticaHindawiwwwhindawicom Volume 2018

Polymer ScienceInternational Journal of

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Advances in Condensed Matter Physics

Hindawiwwwhindawicom Volume 2018

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BiomaterialsHindawiwwwhindawicom

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Hindawiwwwhindawicom Volume 2018

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Hindawiwwwhindawicom Volume 2018

High Energy PhysicsAdvances in

Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawiwwwhindawicom

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Volume 2018

TribologyAdvances in

Hindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

ChemistryAdvances in

Hindawiwwwhindawicom Volume 2018

Advances inPhysical Chemistry

Hindawiwwwhindawicom Volume 2018

BioMed Research InternationalMaterials

Journal of

Hindawiwwwhindawicom Volume 2018

Na

nom

ate

ria

ls

Hindawiwwwhindawicom Volume 2018

Journal ofNanomaterials

Submit your manuscripts atwwwhindawicom

8 International Journal of Biomaterials

Table1TiO2NPapplications

indentureb

asea

ndits

effecto

nthetestedprop

ertie

s

Authorsyear

Particlesiz

eAd

ditio

npercentage

Type

ofAc

rylic

Nanocom

positep

reparatio

nProp

ertie

stested

Specim

ensiz

eEff

ects

(IncreaseD

ecreaseUnchanged)

Chatterje

e2010

[9]

5nm

0-15w

tPM

MAfro

mScientificP

olym

erProd

ucts(O

ntario

NY)

(i)MeasuredTiO2NPmixed

with

PMMAfor5

-10min

(ii)D

ACAtwin-screw

extractio

nprocessa

t190∘C

and100rpm

(iii)Ac

rylic

mixed

for6

-7min

andextrud

ed5tim

es

(i)Tensile

mod

ulus

(ii)D

imensio

nal

stability

(iii)Glasstransition

temperature(T

g)

(iv)U

Vabsorptio

n

10x6x03m

m

5mg

(i)Im

provem

entintensile

mod

ulus

(ii)Increased

thermalsta

bility

(iii)IncreasedT g

(iv)Improvem

entinUV

absorptio

n997888rarr

maxim

umat2

TiO2NP

Chatterje

e2010

[10]

5nm

0 20

50 75

100

150

300

PMMAfro

mScientificP

olym

erProd

ucts(O

ntario

NY)

(i)MeasuredTiO2NPmixed

with

PMMAfor5

-10min

(ii)D

ACAtwin-screw

extractio

nprocessa

t190∘C

and100rpm

(iii)Ac

rylic

mixed

for6

-7min

andextrud

ed5tim

es

(i)Glasstransition

temperature(T

g)

(ii)Th

ermalsta

bility

(iii)Decom

position

temperature

10x6x03m

m

(i)T g

increasedlin

early

upto

75TiO2NP

(ii)Th

ermalsta

bilityincreased

(2-15

TiO2NP)

(iii)Decom

position

temperaturesincreased

with

filler

contentu

pto

10TiO2NP

Aneho

suretal

2012

[11]

31nm

ldquoAnataseph

aserdquo

30

Inadditio

nto

surfa

cecoating

DPI

heatcure

acrylic

resin

(In

dia)

(i)Visib

lelig

htactiv

ated

TiO2NPwe

remixed

with

methylm

ethacrylate

mon

omer

(i)Microbial

inhibitory

effect

againstSA

ureus

5x5x2mm

(i)3w

of

TiO2show

santim

icrobialactiv

ityagainstS

Au

reus

Sodagare

tal2013

[12]

21nm

ldquoAnatase

phaserdquo

0 05 10

SelectaP

lus

(self-c

urea

crylic

resin

)

(i)TiO2NPwe

readdedto

acrylic

mon

omer

(i)Flexuralstr

ength

50x10

x33m

m(i)

Flexuralstr

engthdecreasedas

thefi

llerc

ontent

increased

(i)Flexuralmod

ulus

(i)Nochange

inflexu

ral

mod

ulus

Ham

ouda

and

Beyari

2014

[13]

21nm

50

Con

ventionalh

eat

cure

acrylic

resin

(AcrostonWHN

England)

andhigh

impact(M

etrocryl

HiMetrodent

LTDE

ngland

)

(i)TiO2NPwe

remixed

thorou

ghlywith

acrylic

powd

erby

hand

(ii)F

lexu

ral

strength

(iii)To

ughn

ess

65x10

x25mm

(ii)F

lexu

ralstre

ngth

and

toug

hnessd

ecreased

(iv)M

onom

errelease

(iii)Nodifferenceb

etwe

encontroland

TiO2reinforced

regardingmon

omer

release

International Journal of Biomaterials 9

Table1Con

tinued

Authorsyear

Particlesiz

eAd

ditio

npercentage

Type

ofAc

rylic

Nanocom

positep

reparatio

nProp

ertie

stested

Specim

ensiz

eEff

ects

(IncreaseD

ecreaseUnchanged)

Nazirk

aretal

2014

[14]

7nm

ldquoAnatase

phaserdquo

0 05 10

DPI

heatcure

acrylic

resin

(i)TiO2NPaddedto

acrylic

mon

omer

(i)Flexuralstr

ength

65x10

x33mm

(i)Flexuralstr

engthdecreasedas

theT

iO2am

ount

increased

Shirk

avandand

Moslehifard2014

[15]

lt25

nm(averagesim204

nm)

ldquoAnataseand

Rutilep

hasesrdquo

0 05 10

20

Heatcurea

crylic

resin

from

Ivoclar

Vivadent

(i)TiO2NPwe

remixed

with

thea

crylicresin

polymer

inan

amalgamator

for2

0min

(i)Tensile

strength

60x12

x4mm

(i)Tensile

strengthandelastic

mod

ulus

improved

with

1TiO2NP

(ii)0

5and2

TiO2we

reno

tsig

nificantly

different

from

each

othero

rcon

trol

Harinietal2014

[16]

0 10

20

50

Clearh

eatcure

acrylic

resin

(i)Nanop

artic

lesw

ere

incorporated

into

mon

omer

byultrason

icdispersio

n(i)

Flexuralstr

ength

65x10

x3mm

(i)Flexuralstr

engthim

proved

with

TiO2additio

nsig

nificant

differencen

oticed

with

5

Safi2014

[17]

50

Heatcured

enture

base

acrylic

(Sup

eracrylplus

Czecho

slovakia)

(i)Nanop

artic

lesa

dded

tomon

omer

andsonically

dispersed

(i)Coefficientof

thermalexpansion

(ii)M

odulus

(iii)Glasstransition

15x6mm

Cylin

ders

65x10

x25mm

Powd

erform

(10g)

(i)Decreaseincoeffi

cientof

thermalexpansion

(ii)D

ecreased

inmod

ulus

ofelastic

ity

(iii)IncreasedT g

Alwanand

Alameer2015

[18]

lt50

nmsiz

e0 30

(i)Silanizedwith

TMSP

M

Heatcurea

crylic

resin

(i)SilanizedTiO2NPwe

readdedto

mon

omer

and

sonicated

(i)Im

pactstr

ength

(ii)T

ransverse

strength

(iii)Hardn

ess

(iv)S

urface

roug

hness

(v)W

atersorptio

nandsolubility

80x10

x4mm

65x10x25m

m

50x05m

mdisc

(i)Increased

(ii)Increased

(iii)Increased

(iv)Increased

(v)D

ecreased

10 International Journal of Biomaterials

Table1Con

tinued

Authorsyear

Particlesiz

eAd

ditio

npercentage

Type

ofAc

rylic

Nanocom

positep

reparatio

nProp

ertie

stested

Specim

ensiz

eEff

ects

(IncreaseD

ecreaseUnchanged)

Ahm

edetal2016

[19]

46nm

0 10

50

Con

ventionalh

eat

cure

acrylic

resin

(ImplacrylVe

rtex)

andhigh

impact

heatcureacrylic

resin

(Vertex-Dental

Netherla

nds)

(i)TiO2NPwe

readdedinto

acrylic

resin

(i)Flexuralstr

ength

(ii)Impactstr

ength

(iii)Hardn

ess

50x10

x3mm

60x6x4mm

25x10

x3mm

(i)Decreased

with

TiO2

additio

n

(ii)Increased

onlyfor

conventio

nalacrylicresin

mod

ified

by1

(iii)Increasedwith

5additio

nTiO2NPforb

othtypeso

facrylic

Sodagare

tal2016

[20]

21nm

05 10

SelectaP

lus

(self-c

urea

crylic

resin

)

(i)Nanop

artic

lesw

erea

dded

toacrylic

mon

omer

and

stirred

(i)Antim

icrobial

prop

ertie

s20

x20

x1m

m

(i)TiO2redu

cedmicrobial

grow

thatbo

thconcentrations

at90

min

underU

VAexpo

sure

(ii)A

ntim

icrobialactiv

ityof

TiO2istim

edependent

Ahm

edetal2017

[21]

lt25

nm0 05 10

Heatcurea

crylic

resin

from

Dentsp

lyInternationalInc

(ChicagoIL

USA

)

(i)TiO2NPwe

readdedto

acrylic

polymer

andmixed

usingam

algam

capsule

(i)Flexuralstr

ength

(ii)F

racture

toug

hness

(iii)Hardn

ess

65x10

x25mm

65x10

x25mm

30x10

x25mm

(i)Increasedwith

both

filler

percentages

(ii)N

oeffecto

nfracture

toug

hnesso

fbothfiller

percentages

(iii)Increasedwith

1filler

Hashem

etal2

017

[22]

90nm

0 10

20 30

Self-cureacrylic

resin

from

Eco-crylcold

Protechn

o(Spain)

(i)TiO2NPwe

remixed

with

them

onom

er

(i)Flexuralmod

ulus

andflexu

ral

strength

(ii)H

ardn

ess

(iii)Surfa

cewe

tting

30x8x1m

m

50x1m

mdiscs

(i)Increasedlin

early

(ii)Increased

(iii)Re

ducedwith

1filler

contentand

increasedwith

high

erpercentages

(iv)T

gdecreasedwith

TiO2

additio

n

Ghahrem

anietal

2017

[23]

20-30nm

ldquoAnatase

phaserdquo

0 10

SRTriplexHot

heatcureacrylic

resin

(Ivoclar

Vivadent

Inc

Schaan

Liechtenste

in)

(i)TiO2NPwe

remixed

with

acrylic

resin

powd

erin

anultrason

icmixer

(i)Tensile

strength

(ii)Impactstr

ength

60x12

x39mm

75x10

x10

mm

(i)Increased

(ii)Increased

International Journal of Biomaterials 11Ta

ble1Con

tinued

Authorsyear

Particlesiz

eAd

ditio

npercentage

Type

ofAc

rylic

Nanocom

positep

reparatio

nProp

ertie

stested

Specim

ensiz

eEff

ects

(IncreaseD

ecreaseUnchanged)

Totu

etal2017

[24]

65-170

nm

0 02

04 1 25

PMMA+P

EMAfor

3Dprintin

g(eDent

100En

visio

nTec

GmbH

Gladb

eck

Germany)

(i)Nanop

artic

lesw

erea

dded

into

PMMAsolutio

nwith

continuo

usstirringand

ultrason

icmixingfor1

hour

(i)Antim

icrobial

effect(Ca

ndida

scotti)

(ii)C

omplete

denture

manufacturin

gusin

gste

reolith

ograph

y

(i)041

and25

inhibited

cand

idagrow

th

(ii)P

MMA04TiO2compo

site

successfu

llyused

ford

enture

fabrication

Aziz2018

[25]

30nm

0 30

Highim

pactheat

cure

acrylic

resin

(Vertex-Dental

Netherla

nds)-

(i)TiO2NPwe

redispersedin

mon

omer

andsonicatedat

120W

and60

KHzfor

3minutes

(i)Im

pactstr

ength

(ii)C

olor

stability

(iii)Th

ermal

cond

uctiv

ity

80x10

x4mm

35x15

x05mm

40x25mm

(i)Increased

(ii)Increased

colorstabilityfor

testgrou

ps

(iii)Noeffect

Alra

hlah

etal

2018

[26]

80-100

nm

0 1 2 3

Heatcurea

crylic

resin

(Lucito

ne550Dentsp

lyInt

IncPaU

SA)

(i)Hardn

essa

ndmod

ulus

(ii)T

gdegradation

temperatureand

rate

(iii)Cr

eep-recovery

andrelaxatio

nbehavior

(iv)A

ntibacteria

ladhesio

n

50x10

mm

discs

cutindifferent

sizes

ford

ifferent

tests

7mg

5x10

mm

(i)Increased

(ii)S

light

increase

with

2nano

-fillerc

ontent

(iii)Im

provem

entinbehavior

(iv)D

ecreaseinbacterial

attachmentcon

tent

Karcietal2018

[27]

13nm

0 1 3 5

(i)Au

to-polyeriz

ed(H

eraeus

Kulze

rNew

bury

Berkshire

UK)

(ii)

Heat-p

olym

erized

Heraeus

Kulze

rNew

bury

Berkshire

UK

(iii)Microwave-

polymerized

(GC

DentalTo

kyo

Japan)

(i)TiO2NPwe

remixed

with

acrylic

resin

powd

erusing

ballmillingat40

0rpm

for2

hours

(i)Flexuralstr

ength

65x10

x3mm

(i)Increasedforh

eat-and

auto-polym

erized

acrylic

at1

(ii)D

ecreased

fora

lltypeso

facrylic

at5

12 International Journal of Biomaterials

Table1Con

tinued

Authorsyear

Particlesiz

eAd

ditio

npercentage

Type

ofAc

rylic

Nanocom

positep

reparatio

nProp

ertie

stested

Specim

ensiz

eEff

ects

(IncreaseD

ecreaseUnchanged)

Totu

etalTo

tuet

al2

017[28]

ldquoAnatase

phaserdquo

0 02

04

06 10

25

(i)PM

MA-

MA

(ii)P

MMA-

MMA-

BPO

(iii)3D

printed

PMMA(eD

Envisio

nTec

GmbH

Gladb

eck

Germany)

(i)TiO2mod

ified

bymethacrylicacid

then

manually

mixed

with

PMMAmixture

(i)Th

ermalsta

bility

(ii)T

g

Stereolitho

graphic

dentures

(i)Increased(im

proved)

(ii)Increased

Totu

etal2018

[29]

ldquoAnatase

phaserdquo

0 02

04

06 10

20 25 50

PMMAfor3

Dprintin

g(eDent

100En

visio

nTec

GmbH

Gladb

eck

Germany)

(i)Re

sistance

(ii)E

lectric

alcond

uctiv

ity

(iii)Dielectric

constant

(i)Decreased

with

1020

25

and5

(ii)Increased

butm

aterialstill

maintainedinsulatin

gprop

ertie

s

(iii)Increasedwith

5

International Journal of Biomaterials 13

Conflicts of Interest

The authors declare that they have no conflicts of interest

References

[1] R L Sakaguchi and J M Powers Craigrsquos Restorative DentalMaterials Elsevier Health Sciences Philadelphia PA USA pp163-176 2012

[2] N Murakami N Wakabayashi R Matsushima A Kishidaand Y Igarashi ldquoEffect of high-pressure polymerization onmechanical properties of PMMA denture base resinrdquo Journalof the Mechanical Behavior of Biomedical Materials vol 20 pp98ndash104 2013

[3] R Adhikari and G H Michler ldquoPolymer nanocompositescharacterization by microscopyrdquo Polymer Reviews vol 49 no3 pp 141ndash180 2009

[4] A Navidfar T Azdast and A Karimzad Ghavidel ldquoInfluenceof processing condition and carbon nanotube on mechani-cal properties of injection molded multi-walled carbon nan-otubepoly(methyl methacrylate) nanocompositesrdquo Journal ofApplied Polymer Science vol 133 no 31 Article ID 43738 pp1ndash9 2016

[5] P Chaijareenont H Takahashi N Nishiyama and M Ark-sornnukit ldquoEffect of different amounts of 3-methacryloxypro-pyltrimethoxysilane on the flexural properties and wear resis-tance of alumina reinforced PMMArdquo Dental Materials vol 31no 4 pp 623ndash628 2012

[6] J Jordan K I Jacob R TannenbaumMA Sharaf and I JasiukldquoExperimental trends in polymer nanocompositesmdasha reviewrdquoMaterials Science and Engineering A vol 393 no 1-2 pp 1ndash112005

[7] MMGad SM Fouda F A Al-Harbi RNapankangas andARaustia ldquoPMMAdenture base material enhancement A reviewof fiber filler and nanofiller additionrdquo International Journal ofNanomedicine vol 12 pp 3801ndash3812 2017

[8] F Li S Zhou B You and L Wu ldquoKinetic study onthe UV-induced photopolymerization of epoxy acrylateTiO2nanocomposites by FTIR spectroscopyrdquo Journal of AppliedPolymer Science vol 99 no 6 pp 3281ndash3287 2006

[9] A Chatterjee ldquoProperties improvement of PMMA using nanoTiO2rdquo Journal of Applied Polymer Science vol 118 no 5 pp2890ndash2897 2010

[10] P Harini K Mohamed and T V Padmanabhan ldquoEffect ofTitanium dioxide nanoparticles on the flexural strength ofpolymethylmethacrylate An in vitro studyrdquo Indian Journal ofDental Research vol 25 no 4 pp 459ndash463 2014

[11] G Venkatesh Anehosur R D Kulkarni M G Naik et alldquoSynthesis and Determination of Antimicrobial Activity ofVisible Light Activated TiO2 Nanoparticles with PolymethylMethacrylate Denture Base Resin Against StaphylococcusAureusrdquo Journal of Gerontology ampGeriatric Research vol 01 no01 pp 103ndash111 2012

[12] A Sodagar A Bahador S Khalil A Saffar Shahroudi and MZaman Kassaee ldquoThe effect of TiO

2and SiO

2nanoparticles on

flexural strength of poly (methyl methacrylate) acrylic resinsrdquoJournal of Prosthodontic Research vol 57 no 1 pp 15ndash19 2013

[13] I M Hamouda and M M Beyari ldquoAddition of glass fibers andtitanium dioxide nanoparticles to the acrylic resin denture basematerial comparative study with the conventional and highimpact typesrdquo Oral Health and Dental Management vol 13 pp107ndash112 2014

[14] E E Totu C M Cristache E Voicila et al ldquoOn physicaland chemical characteristics of Poly(methylmethacrylate) na-nocomposites for dental applications IrdquoMateriale Plastice vol54 no 4 pp 666ndash672 2017

[15] S Shirkavand and EMoslehifard ldquoEffect of TiO2 nanoparticleson tensile strength of dental acrylic resinsrdquo Journal of DentalResearch Dental Clinics Dental Prospects vol 8 no 4 pp 197ndash203 2014

[16] M Karci N Demir and S Yazman ldquoEvaluation of FlexuralStrength of Different Denture Base Materials Reinforced withDifferent Nanoparticlesrdquo Journal of Prosthodontics 2018

[17] O Gurbuz F Unalan and I Dikbas ldquoComparison of thetransverse strength of six acrylic denture resinsrdquo OhdmbscMagazines vol 9 pp 21ndash24 2010

[18] S A Alwan and S S Alameer ldquoThe Effect of the Addition ofSilanized Nano Titania Fillers on Some Physical and Mechan-ical Properties of Heat Cured Acrylic Denture Base MaterialsrdquoJournal of Baghdad College of Dentistry vol 27 no 1 pp 86ndash912015

[19] M Ashour Ahmed M El-Shennawy Y M Althomali andA A Omar ldquoEffect of Titanium Dioxide Nano Particles In-corporation on Mechanical and Physical Properties on TwoDifferent Types of Acrylic Resin Denture Baserdquo World Journalof Nanoscience and Engineering vol 06 no 03 pp 111ndash119 2016

[20] A Sodagar S Khalil M Z Kassaee A S Shahroudi B Pourak-bari and A Bahador ldquoAntimicrobial properties of poly (methylmethacrylate) acrylic resins incorporated with silicon dioxideand titanium dioxide nanoparticles on cariogenic bacteriardquoJournal of Orthodontic Science vol 5 no 1 pp 7ndash13 2016

[21] M A Ahmed A A Omar M El-Shennawy M I Ebrahimand Y M Althomali ldquoInfluence of addition of different types ofnano-fillers on the microstructure and mechanical propertiesof PMMA based denture resinrdquo Kasmera Journal vol 45 pp48ndash59 2017

[22] MHashemM F Al Rez H Fouad et al ldquoInfluence of titaniumoxide nanoparticles on the physical and thermomechanicalbehavior of poly methyl methacrylate (pmma) A denture baseresinrdquo Science of Advanced Materials vol 9 no 6 pp 938ndash9442017

[23] L Ghahremani S Shirkavand F Akbari and N SabzikarildquoTensile strength and impact strength of color modified acrylicresin reinforcedwith titaniumdioxide nanoparticlesrdquo Journal ofClinical and Experimental Dentistry vol 9 no 5 pp e661ndashe6652017

[24] E E Totu A C Nechifor G Nechifor H Y Aboul-Eneinand C M Cristache ldquoPoly(methyl methacrylate) with TiO2nanoparticles inclusion for stereolitographic complete denturemanufacturing minus the fututre in dental care for elderly edentu-lous patientsrdquo Journal of Dentistry vol 59 pp 68ndash77 2017

[25] H K Aziz ldquoTiO-Nanofillers Effects on Some Properties ofHighly- Impact Resin Using Different Processing TechniquesrdquoThe Open Dentistry Journal vol 12 no 1 pp 202ndash212 2018

[26] M Tsuji T Ueda K Sawaki M Kawaguchi and K SakuraildquoBiocompatibility of a titanium dioxide-coating method fordenture base acrylic resinrdquo Gerodontology vol 33 no 4 pp539ndash544 2016

[27] S PodzimekM Tomka P Sommerova Y Lyuya-Mi J Bartovaand J Prochazkova ldquoImmune markers in oral discomfortpatients before and after elimination of oral galvanismrdquo Neu-roendocrinology Letters vol 34 no 8 pp 802ndash808 2013

[28] S Kiat-amnuayM Beerbower JM Powers andRD ParavinaldquoInfluence of pigments and opacifiers on color stability of

14 International Journal of Biomaterials

siliconemaxillofacial elastomerrdquo Journal ofDentistry vol 37 no1 pp e45ndashe50 2009

[29] S H Tuna F Keyf H O Gumus and C Uzun ldquoThe evaluationof water sorptionsolubility of various acrylic resinsrdquo EuropeanJournal of Dental Education vol 2 pp 191ndash197 2008

[30] S M Khaled R Sui P A Charpentier and A S RizkallaldquoSynthesis of TiO

2-PMMA nanocomposite using methacrylic

acid as a coupling agentrdquo Langmuir vol 23 no 7 pp 3988ndash39952007

[31] L Reijnders ldquoThe release of TiO2 and SiO2 nanoparticles fromnanocompositesrdquo Polymer Degradation and Stability vol 94no 5 pp 873ndash876 2009

[32] G Nazirkar S Bhanushali S Singh B Pattanaik and N RajldquoEffect of Anatase Titanium Dioxide Nanoparticles on theFlexural Strength of Heat Cured Poly Methyl MethacrylateResins An In-Vitro Studyrdquo Journal of Indian ProsthodontistSociety vol 14 pp 144ndash149 2014

[33] A Chatterjee ldquoEffect of nanoTiO2addition on poly(methyl

methacrylate) an exciting nanocompositerdquo Journal of AppliedPolymer Science vol 116 no 6 pp 3396ndash3407 2010

[34] S Rashahmadi R Hasanzadeh and S Mosalman ldquoImprov-ing the Mechanical Properties of Poly Methyl MethacrylateNanocomposites for Dentistry Applications Reinforced withDifferent Nanoparticlesrdquo PolymermdashPlastics Technology andEngineering vol 56 no 16 pp 1730ndash1740 2017

[35] A H Yuwono B Liu J Xue et al ldquoControlling the crystallinityand nonlinear optical properties of transparent TiO

2-PMMA

nanohybridsrdquo Journal of Materials Chemistry vol 14 no 20 pp2978ndash2987 2004

[36] J K Pandey K RaghunathaReddy A P Kumar andR P SinghldquoAn overviewon the degradability of polymer nanocompositesrdquoPolymer Degradation and Stability vol 88 no 2 pp 234ndash2502005

[37] C Tao S Jianping J Weng L Ting and H Xiaozhu ldquoPrepara-tion and properties of PMMATiO2 nanocompositerdquoChemicalReaction Engineering andTechnology vol 23 pp 435ndash440 2007

[38] A H Yuwono J Xue J Wang et al ldquoTransparent nanohybridsof nanocrystalline TiO2 in PMMA with unique nonlinearoptical behaviorrdquo Journal of Materials Chemistry vol 13 no 6pp 1475ndash1479 2003

[39] R Alla K N Raghavendra R Vyas and A KonakanchildquoConventional and contemporary polymers for the fabricationof denture prosthesis Part I overview composition and proper-tiesrdquo International Journal of Applied Dental Sciences vol 1 noPart I pp 82ndash89 2015

[40] C C Trapalis P Keivanidis G Kordas et al ldquoTiO2(Fe3+)nanostructured thin films with antibacterial propertiesrdquo ThinSolid Films vol 433 no 1-2 pp 186ndash190 2003

[41] L S Acosta-Torres L M Lopez-Marın R E Nunez-Anita GHernandez-Padron and V M Castano ldquoBiocompatible Metal-Oxide Nanoparticles Nanotechnology Improvement of Con-ventional Prosthetic Acrylic Resinsrdquo Journal of Nanomaterialsvol 2011 Article ID 941561 8 pages 2011

[42] A Bahador S Khalil B Pourakbari et al ldquoPhotocatalyticEffects of Acrylic Resins Incorporated with Nano-titaniumDioxide on Planktonic and Biofilm Growth of Four CariogenicBacteriardquo Annual Research amp Review in Biology vol 4 no 17pp 2695ndash2708 2014

[43] A Alrahlah H Fouad M Hashem A Niazy and A AlBadahldquoTitanium Oxide (TiO2)Polymethylmethacrylate (PMMA)Denture Base Nanocomposites Mechanical Viscoelastic and

Antibacterial BehaviorrdquoMaterials vol 11 no 7 Article ID 1096pp 10961ndash109615 2018

[44] A Kubacka M Ferrer M L Cerrada et al ldquoBoostingTiO2-anatase antimicrobial activity Polymer-oxide thin filmsrdquoApplied Catalysis B Environmental vol 89 no 3-4 pp 441ndash4472009

[45] Y Cheng T Sakai R Moroi et al ldquoSelf-cleaning abilityof a photocatalyst-containing denture base materialrdquo DentalMaterials vol 27 no 2 pp 179ndash186 2008

[46] C M Bollen P Lambrechts and M Quirynen ldquoComparisonof surface roughness of oral hard materials to the thresholdsurface roughness for bacterial plaque retention a review of theliteraturerdquoDental Materials vol 13 no 4 pp 258ndash269 1997

[47] N Elshereksi M Ghazali A Muchtar and C Azhari ldquoEffectof nanobarium titanate addition on the surface characteristicsof denture base resinrdquo International Journal of Mechanical andProduction Engineering vol 5 pp 1ndash8 2017

[48] Y Xia Z Feimin H Xie and N Gu ldquoNanoparticles reinforcedresin based dental compositesrdquo Journal of Dentistry vol 36 pp450ndash455 2008

[49] S Mosalman S Rashahmadi and R Hasanzadeh ldquoThe effectof TiO2 nanoparticles on mechanical properties of poly methylmethacrylate nanocompositesrdquo International Journal of Engi-neering Transactions B Applications vol 30 no 5 pp 807ndash8132017

[50] Y Han S Kiat-amnuay J M Powers and Y Zhao ldquoEffectof nano-oxide concentration on the mechanical properties ofa maxillofacial silicone elastomerrdquo The Journal of ProstheticDentistry vol 100 no 6 pp 465ndash473 2008

[51] I N Safi ldquoEvaluation the effect of nanomdashfillers (TiO2 AL2O3

SiO2) addition on glass transition temperature E-moudulus

and coefficient of thermal expansion of acrylic denture basematerialrdquo Journal of Baghdad College of Dentistry vol 26 no1 pp 37ndash41 2014

[52] W Wang S Liao Y Zhu M Liu Q Zhao and Y Fu ldquoRecentApplications of Nanomaterials in Prosthodonticsrdquo Journal ofNanomaterials vol 2015 Article ID 408643 11 pages 2015

[53] L Sun R F Gibson F Gordaninejad and J Suhr ldquoEnergyabsorption capability of nanocomposites A reviewrdquoCompositesScience and Technology vol 69 no 14 pp 2392ndash2409 2009

[54] S Podzimek K Hana M Miksovsky et al ldquoThe Influence ofgalvanic currents and voltage on the proliferation activity oflymphocytes and expression of cell surface moleculesrdquo FoliaBiologica vol 54 no 5 pp 146ndash150 2008

[55] E E Totu E Voicila V Pistritu G Nechifor and C MCristache ldquoEvaluation of electrical characteristics for PMMA-TiO2 nanocomposites used in dentistryrdquo Evista de Chimie vol69 no 1 pp 155ndash159 2018

CorrosionInternational Journal of

Hindawiwwwhindawicom Volume 2018

Advances in

Materials Science and EngineeringHindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

Journal of

Chemistry

Analytical ChemistryInternational Journal of

Hindawiwwwhindawicom Volume 2018

ScienticaHindawiwwwhindawicom Volume 2018

Polymer ScienceInternational Journal of

Hindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

Advances in Condensed Matter Physics

Hindawiwwwhindawicom Volume 2018

International Journal of

BiomaterialsHindawiwwwhindawicom

Journal ofEngineeringVolume 2018

Applied ChemistryJournal of

Hindawiwwwhindawicom Volume 2018

NanotechnologyHindawiwwwhindawicom Volume 2018

Journal of

Hindawiwwwhindawicom Volume 2018

High Energy PhysicsAdvances in

Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawiwwwhindawicom

The Scientific World Journal

Volume 2018

TribologyAdvances in

Hindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

ChemistryAdvances in

Hindawiwwwhindawicom Volume 2018

Advances inPhysical Chemistry

Hindawiwwwhindawicom Volume 2018

BioMed Research InternationalMaterials

Journal of

Hindawiwwwhindawicom Volume 2018

Na

nom

ate

ria

ls

Hindawiwwwhindawicom Volume 2018

Journal ofNanomaterials

Submit your manuscripts atwwwhindawicom

International Journal of Biomaterials 9

Table1Con

tinued

Authorsyear

Particlesiz

eAd

ditio

npercentage

Type

ofAc

rylic

Nanocom

positep

reparatio

nProp

ertie

stested

Specim

ensiz

eEff

ects

(IncreaseD

ecreaseUnchanged)

Nazirk

aretal

2014

[14]

7nm

ldquoAnatase

phaserdquo

0 05 10

DPI

heatcure

acrylic

resin

(i)TiO2NPaddedto

acrylic

mon

omer

(i)Flexuralstr

ength

65x10

x33mm

(i)Flexuralstr

engthdecreasedas

theT

iO2am

ount

increased

Shirk

avandand

Moslehifard2014

[15]

lt25

nm(averagesim204

nm)

ldquoAnataseand

Rutilep

hasesrdquo

0 05 10

20

Heatcurea

crylic

resin

from

Ivoclar

Vivadent

(i)TiO2NPwe

remixed

with

thea

crylicresin

polymer

inan

amalgamator

for2

0min

(i)Tensile

strength

60x12

x4mm

(i)Tensile

strengthandelastic

mod

ulus

improved

with

1TiO2NP

(ii)0

5and2

TiO2we

reno

tsig

nificantly

different

from

each

othero

rcon

trol

Harinietal2014

[16]

0 10

20

50

Clearh

eatcure

acrylic

resin

(i)Nanop

artic

lesw

ere

incorporated

into

mon

omer

byultrason

icdispersio

n(i)

Flexuralstr

ength

65x10

x3mm

(i)Flexuralstr

engthim

proved

with

TiO2additio

nsig

nificant

differencen

oticed

with

5

Safi2014

[17]

50

Heatcured

enture

base

acrylic

(Sup

eracrylplus

Czecho

slovakia)

(i)Nanop

artic

lesa

dded

tomon

omer

andsonically

dispersed

(i)Coefficientof

thermalexpansion

(ii)M

odulus

(iii)Glasstransition

15x6mm

Cylin

ders

65x10

x25mm

Powd

erform

(10g)

(i)Decreaseincoeffi

cientof

thermalexpansion

(ii)D

ecreased

inmod

ulus

ofelastic

ity

(iii)IncreasedT g

Alwanand

Alameer2015

[18]

lt50

nmsiz

e0 30

(i)Silanizedwith

TMSP

M

Heatcurea

crylic

resin

(i)SilanizedTiO2NPwe

readdedto

mon

omer

and

sonicated

(i)Im

pactstr

ength

(ii)T

ransverse

strength

(iii)Hardn

ess

(iv)S

urface

roug

hness

(v)W

atersorptio

nandsolubility

80x10

x4mm

65x10x25m

m

50x05m

mdisc

(i)Increased

(ii)Increased

(iii)Increased

(iv)Increased

(v)D

ecreased

10 International Journal of Biomaterials

Table1Con

tinued

Authorsyear

Particlesiz

eAd

ditio

npercentage

Type

ofAc

rylic

Nanocom

positep

reparatio

nProp

ertie

stested

Specim

ensiz

eEff

ects

(IncreaseD

ecreaseUnchanged)

Ahm

edetal2016

[19]

46nm

0 10

50

Con

ventionalh

eat

cure

acrylic

resin

(ImplacrylVe

rtex)

andhigh

impact

heatcureacrylic

resin

(Vertex-Dental

Netherla

nds)

(i)TiO2NPwe

readdedinto

acrylic

resin

(i)Flexuralstr

ength

(ii)Impactstr

ength

(iii)Hardn

ess

50x10

x3mm

60x6x4mm

25x10

x3mm

(i)Decreased

with

TiO2

additio

n

(ii)Increased

onlyfor

conventio

nalacrylicresin

mod

ified

by1

(iii)Increasedwith

5additio

nTiO2NPforb

othtypeso

facrylic

Sodagare

tal2016

[20]

21nm

05 10

SelectaP

lus

(self-c

urea

crylic

resin

)

(i)Nanop

artic

lesw

erea

dded

toacrylic

mon

omer

and

stirred

(i)Antim

icrobial

prop

ertie

s20

x20

x1m

m

(i)TiO2redu

cedmicrobial

grow

thatbo

thconcentrations

at90

min

underU

VAexpo

sure

(ii)A

ntim

icrobialactiv

ityof

TiO2istim

edependent

Ahm

edetal2017

[21]

lt25

nm0 05 10

Heatcurea

crylic

resin

from

Dentsp

lyInternationalInc

(ChicagoIL

USA

)

(i)TiO2NPwe

readdedto

acrylic

polymer

andmixed

usingam

algam

capsule

(i)Flexuralstr

ength

(ii)F

racture

toug

hness

(iii)Hardn

ess

65x10

x25mm

65x10

x25mm

30x10

x25mm

(i)Increasedwith

both

filler

percentages

(ii)N

oeffecto

nfracture

toug

hnesso

fbothfiller

percentages

(iii)Increasedwith

1filler

Hashem

etal2

017

[22]

90nm

0 10

20 30

Self-cureacrylic

resin

from

Eco-crylcold

Protechn

o(Spain)

(i)TiO2NPwe

remixed

with

them

onom

er

(i)Flexuralmod

ulus

andflexu

ral

strength

(ii)H

ardn

ess

(iii)Surfa

cewe

tting

30x8x1m

m

50x1m

mdiscs

(i)Increasedlin

early

(ii)Increased

(iii)Re

ducedwith

1filler

contentand

increasedwith

high

erpercentages

(iv)T

gdecreasedwith

TiO2

additio

n

Ghahrem

anietal

2017

[23]

20-30nm

ldquoAnatase

phaserdquo

0 10

SRTriplexHot

heatcureacrylic

resin

(Ivoclar

Vivadent

Inc

Schaan

Liechtenste

in)

(i)TiO2NPwe

remixed

with

acrylic

resin

powd

erin

anultrason

icmixer

(i)Tensile

strength

(ii)Impactstr

ength

60x12

x39mm

75x10

x10

mm

(i)Increased

(ii)Increased

International Journal of Biomaterials 11Ta

ble1Con

tinued

Authorsyear

Particlesiz

eAd

ditio

npercentage

Type

ofAc

rylic

Nanocom

positep

reparatio

nProp

ertie

stested

Specim

ensiz

eEff

ects

(IncreaseD

ecreaseUnchanged)

Totu

etal2017

[24]

65-170

nm

0 02

04 1 25

PMMA+P

EMAfor

3Dprintin

g(eDent

100En

visio

nTec

GmbH

Gladb

eck

Germany)

(i)Nanop

artic

lesw

erea

dded

into

PMMAsolutio

nwith

continuo

usstirringand

ultrason

icmixingfor1

hour

(i)Antim

icrobial

effect(Ca

ndida

scotti)

(ii)C

omplete

denture

manufacturin

gusin

gste

reolith

ograph

y

(i)041

and25

inhibited

cand

idagrow

th

(ii)P

MMA04TiO2compo

site

successfu

llyused

ford

enture

fabrication

Aziz2018

[25]

30nm

0 30

Highim

pactheat

cure

acrylic

resin

(Vertex-Dental

Netherla

nds)-

(i)TiO2NPwe

redispersedin

mon

omer

andsonicatedat

120W

and60

KHzfor

3minutes

(i)Im

pactstr

ength

(ii)C

olor

stability

(iii)Th

ermal

cond

uctiv

ity

80x10

x4mm

35x15

x05mm

40x25mm

(i)Increased

(ii)Increased

colorstabilityfor

testgrou

ps

(iii)Noeffect

Alra

hlah

etal

2018

[26]

80-100

nm

0 1 2 3

Heatcurea

crylic

resin

(Lucito

ne550Dentsp

lyInt

IncPaU

SA)

(i)Hardn

essa

ndmod

ulus

(ii)T

gdegradation

temperatureand

rate

(iii)Cr

eep-recovery

andrelaxatio

nbehavior

(iv)A

ntibacteria

ladhesio

n

50x10

mm

discs

cutindifferent

sizes

ford

ifferent

tests

7mg

5x10

mm

(i)Increased

(ii)S

light

increase

with

2nano

-fillerc

ontent

(iii)Im

provem

entinbehavior

(iv)D

ecreaseinbacterial

attachmentcon

tent

Karcietal2018

[27]

13nm

0 1 3 5

(i)Au

to-polyeriz

ed(H

eraeus

Kulze

rNew

bury

Berkshire

UK)

(ii)

Heat-p

olym

erized

Heraeus

Kulze

rNew

bury

Berkshire

UK

(iii)Microwave-

polymerized

(GC

DentalTo

kyo

Japan)

(i)TiO2NPwe

remixed

with

acrylic

resin

powd

erusing

ballmillingat40

0rpm

for2

hours

(i)Flexuralstr

ength

65x10

x3mm

(i)Increasedforh

eat-and

auto-polym

erized

acrylic

at1

(ii)D

ecreased

fora

lltypeso

facrylic

at5

12 International Journal of Biomaterials

Table1Con

tinued

Authorsyear

Particlesiz

eAd

ditio

npercentage

Type

ofAc

rylic

Nanocom

positep

reparatio

nProp

ertie

stested

Specim

ensiz

eEff

ects

(IncreaseD

ecreaseUnchanged)

Totu

etalTo

tuet

al2

017[28]

ldquoAnatase

phaserdquo

0 02

04

06 10

25

(i)PM

MA-

MA

(ii)P

MMA-

MMA-

BPO

(iii)3D

printed

PMMA(eD

Envisio

nTec

GmbH

Gladb

eck

Germany)

(i)TiO2mod

ified

bymethacrylicacid

then

manually

mixed

with

PMMAmixture

(i)Th

ermalsta

bility

(ii)T

g

Stereolitho

graphic

dentures

(i)Increased(im

proved)

(ii)Increased

Totu

etal2018

[29]

ldquoAnatase

phaserdquo

0 02

04

06 10

20 25 50

PMMAfor3

Dprintin

g(eDent

100En

visio

nTec

GmbH

Gladb

eck

Germany)

(i)Re

sistance

(ii)E

lectric

alcond

uctiv

ity

(iii)Dielectric

constant

(i)Decreased

with

1020

25

and5

(ii)Increased

butm

aterialstill

maintainedinsulatin

gprop

ertie

s

(iii)Increasedwith

5

International Journal of Biomaterials 13

Conflicts of Interest

The authors declare that they have no conflicts of interest

References

[1] R L Sakaguchi and J M Powers Craigrsquos Restorative DentalMaterials Elsevier Health Sciences Philadelphia PA USA pp163-176 2012

[2] N Murakami N Wakabayashi R Matsushima A Kishidaand Y Igarashi ldquoEffect of high-pressure polymerization onmechanical properties of PMMA denture base resinrdquo Journalof the Mechanical Behavior of Biomedical Materials vol 20 pp98ndash104 2013

[3] R Adhikari and G H Michler ldquoPolymer nanocompositescharacterization by microscopyrdquo Polymer Reviews vol 49 no3 pp 141ndash180 2009

[4] A Navidfar T Azdast and A Karimzad Ghavidel ldquoInfluenceof processing condition and carbon nanotube on mechani-cal properties of injection molded multi-walled carbon nan-otubepoly(methyl methacrylate) nanocompositesrdquo Journal ofApplied Polymer Science vol 133 no 31 Article ID 43738 pp1ndash9 2016

[5] P Chaijareenont H Takahashi N Nishiyama and M Ark-sornnukit ldquoEffect of different amounts of 3-methacryloxypro-pyltrimethoxysilane on the flexural properties and wear resis-tance of alumina reinforced PMMArdquo Dental Materials vol 31no 4 pp 623ndash628 2012

[6] J Jordan K I Jacob R TannenbaumMA Sharaf and I JasiukldquoExperimental trends in polymer nanocompositesmdasha reviewrdquoMaterials Science and Engineering A vol 393 no 1-2 pp 1ndash112005

[7] MMGad SM Fouda F A Al-Harbi RNapankangas andARaustia ldquoPMMAdenture base material enhancement A reviewof fiber filler and nanofiller additionrdquo International Journal ofNanomedicine vol 12 pp 3801ndash3812 2017

[8] F Li S Zhou B You and L Wu ldquoKinetic study onthe UV-induced photopolymerization of epoxy acrylateTiO2nanocomposites by FTIR spectroscopyrdquo Journal of AppliedPolymer Science vol 99 no 6 pp 3281ndash3287 2006

[9] A Chatterjee ldquoProperties improvement of PMMA using nanoTiO2rdquo Journal of Applied Polymer Science vol 118 no 5 pp2890ndash2897 2010

[10] P Harini K Mohamed and T V Padmanabhan ldquoEffect ofTitanium dioxide nanoparticles on the flexural strength ofpolymethylmethacrylate An in vitro studyrdquo Indian Journal ofDental Research vol 25 no 4 pp 459ndash463 2014

[11] G Venkatesh Anehosur R D Kulkarni M G Naik et alldquoSynthesis and Determination of Antimicrobial Activity ofVisible Light Activated TiO2 Nanoparticles with PolymethylMethacrylate Denture Base Resin Against StaphylococcusAureusrdquo Journal of Gerontology ampGeriatric Research vol 01 no01 pp 103ndash111 2012

[12] A Sodagar A Bahador S Khalil A Saffar Shahroudi and MZaman Kassaee ldquoThe effect of TiO

2and SiO

2nanoparticles on

flexural strength of poly (methyl methacrylate) acrylic resinsrdquoJournal of Prosthodontic Research vol 57 no 1 pp 15ndash19 2013

[13] I M Hamouda and M M Beyari ldquoAddition of glass fibers andtitanium dioxide nanoparticles to the acrylic resin denture basematerial comparative study with the conventional and highimpact typesrdquo Oral Health and Dental Management vol 13 pp107ndash112 2014

[14] E E Totu C M Cristache E Voicila et al ldquoOn physicaland chemical characteristics of Poly(methylmethacrylate) na-nocomposites for dental applications IrdquoMateriale Plastice vol54 no 4 pp 666ndash672 2017

[15] S Shirkavand and EMoslehifard ldquoEffect of TiO2 nanoparticleson tensile strength of dental acrylic resinsrdquo Journal of DentalResearch Dental Clinics Dental Prospects vol 8 no 4 pp 197ndash203 2014

[16] M Karci N Demir and S Yazman ldquoEvaluation of FlexuralStrength of Different Denture Base Materials Reinforced withDifferent Nanoparticlesrdquo Journal of Prosthodontics 2018

[17] O Gurbuz F Unalan and I Dikbas ldquoComparison of thetransverse strength of six acrylic denture resinsrdquo OhdmbscMagazines vol 9 pp 21ndash24 2010

[18] S A Alwan and S S Alameer ldquoThe Effect of the Addition ofSilanized Nano Titania Fillers on Some Physical and Mechan-ical Properties of Heat Cured Acrylic Denture Base MaterialsrdquoJournal of Baghdad College of Dentistry vol 27 no 1 pp 86ndash912015

[19] M Ashour Ahmed M El-Shennawy Y M Althomali andA A Omar ldquoEffect of Titanium Dioxide Nano Particles In-corporation on Mechanical and Physical Properties on TwoDifferent Types of Acrylic Resin Denture Baserdquo World Journalof Nanoscience and Engineering vol 06 no 03 pp 111ndash119 2016

[20] A Sodagar S Khalil M Z Kassaee A S Shahroudi B Pourak-bari and A Bahador ldquoAntimicrobial properties of poly (methylmethacrylate) acrylic resins incorporated with silicon dioxideand titanium dioxide nanoparticles on cariogenic bacteriardquoJournal of Orthodontic Science vol 5 no 1 pp 7ndash13 2016

[21] M A Ahmed A A Omar M El-Shennawy M I Ebrahimand Y M Althomali ldquoInfluence of addition of different types ofnano-fillers on the microstructure and mechanical propertiesof PMMA based denture resinrdquo Kasmera Journal vol 45 pp48ndash59 2017

[22] MHashemM F Al Rez H Fouad et al ldquoInfluence of titaniumoxide nanoparticles on the physical and thermomechanicalbehavior of poly methyl methacrylate (pmma) A denture baseresinrdquo Science of Advanced Materials vol 9 no 6 pp 938ndash9442017

[23] L Ghahremani S Shirkavand F Akbari and N SabzikarildquoTensile strength and impact strength of color modified acrylicresin reinforcedwith titaniumdioxide nanoparticlesrdquo Journal ofClinical and Experimental Dentistry vol 9 no 5 pp e661ndashe6652017

[24] E E Totu A C Nechifor G Nechifor H Y Aboul-Eneinand C M Cristache ldquoPoly(methyl methacrylate) with TiO2nanoparticles inclusion for stereolitographic complete denturemanufacturing minus the fututre in dental care for elderly edentu-lous patientsrdquo Journal of Dentistry vol 59 pp 68ndash77 2017

[25] H K Aziz ldquoTiO-Nanofillers Effects on Some Properties ofHighly- Impact Resin Using Different Processing TechniquesrdquoThe Open Dentistry Journal vol 12 no 1 pp 202ndash212 2018

[26] M Tsuji T Ueda K Sawaki M Kawaguchi and K SakuraildquoBiocompatibility of a titanium dioxide-coating method fordenture base acrylic resinrdquo Gerodontology vol 33 no 4 pp539ndash544 2016

[27] S PodzimekM Tomka P Sommerova Y Lyuya-Mi J Bartovaand J Prochazkova ldquoImmune markers in oral discomfortpatients before and after elimination of oral galvanismrdquo Neu-roendocrinology Letters vol 34 no 8 pp 802ndash808 2013

[28] S Kiat-amnuayM Beerbower JM Powers andRD ParavinaldquoInfluence of pigments and opacifiers on color stability of

14 International Journal of Biomaterials

siliconemaxillofacial elastomerrdquo Journal ofDentistry vol 37 no1 pp e45ndashe50 2009

[29] S H Tuna F Keyf H O Gumus and C Uzun ldquoThe evaluationof water sorptionsolubility of various acrylic resinsrdquo EuropeanJournal of Dental Education vol 2 pp 191ndash197 2008

[30] S M Khaled R Sui P A Charpentier and A S RizkallaldquoSynthesis of TiO

2-PMMA nanocomposite using methacrylic

acid as a coupling agentrdquo Langmuir vol 23 no 7 pp 3988ndash39952007

[31] L Reijnders ldquoThe release of TiO2 and SiO2 nanoparticles fromnanocompositesrdquo Polymer Degradation and Stability vol 94no 5 pp 873ndash876 2009

[32] G Nazirkar S Bhanushali S Singh B Pattanaik and N RajldquoEffect of Anatase Titanium Dioxide Nanoparticles on theFlexural Strength of Heat Cured Poly Methyl MethacrylateResins An In-Vitro Studyrdquo Journal of Indian ProsthodontistSociety vol 14 pp 144ndash149 2014

[33] A Chatterjee ldquoEffect of nanoTiO2addition on poly(methyl

methacrylate) an exciting nanocompositerdquo Journal of AppliedPolymer Science vol 116 no 6 pp 3396ndash3407 2010

[34] S Rashahmadi R Hasanzadeh and S Mosalman ldquoImprov-ing the Mechanical Properties of Poly Methyl MethacrylateNanocomposites for Dentistry Applications Reinforced withDifferent Nanoparticlesrdquo PolymermdashPlastics Technology andEngineering vol 56 no 16 pp 1730ndash1740 2017

[35] A H Yuwono B Liu J Xue et al ldquoControlling the crystallinityand nonlinear optical properties of transparent TiO

2-PMMA

nanohybridsrdquo Journal of Materials Chemistry vol 14 no 20 pp2978ndash2987 2004

[36] J K Pandey K RaghunathaReddy A P Kumar andR P SinghldquoAn overviewon the degradability of polymer nanocompositesrdquoPolymer Degradation and Stability vol 88 no 2 pp 234ndash2502005

[37] C Tao S Jianping J Weng L Ting and H Xiaozhu ldquoPrepara-tion and properties of PMMATiO2 nanocompositerdquoChemicalReaction Engineering andTechnology vol 23 pp 435ndash440 2007

[38] A H Yuwono J Xue J Wang et al ldquoTransparent nanohybridsof nanocrystalline TiO2 in PMMA with unique nonlinearoptical behaviorrdquo Journal of Materials Chemistry vol 13 no 6pp 1475ndash1479 2003

[39] R Alla K N Raghavendra R Vyas and A KonakanchildquoConventional and contemporary polymers for the fabricationof denture prosthesis Part I overview composition and proper-tiesrdquo International Journal of Applied Dental Sciences vol 1 noPart I pp 82ndash89 2015

[40] C C Trapalis P Keivanidis G Kordas et al ldquoTiO2(Fe3+)nanostructured thin films with antibacterial propertiesrdquo ThinSolid Films vol 433 no 1-2 pp 186ndash190 2003

[41] L S Acosta-Torres L M Lopez-Marın R E Nunez-Anita GHernandez-Padron and V M Castano ldquoBiocompatible Metal-Oxide Nanoparticles Nanotechnology Improvement of Con-ventional Prosthetic Acrylic Resinsrdquo Journal of Nanomaterialsvol 2011 Article ID 941561 8 pages 2011

[42] A Bahador S Khalil B Pourakbari et al ldquoPhotocatalyticEffects of Acrylic Resins Incorporated with Nano-titaniumDioxide on Planktonic and Biofilm Growth of Four CariogenicBacteriardquo Annual Research amp Review in Biology vol 4 no 17pp 2695ndash2708 2014

[43] A Alrahlah H Fouad M Hashem A Niazy and A AlBadahldquoTitanium Oxide (TiO2)Polymethylmethacrylate (PMMA)Denture Base Nanocomposites Mechanical Viscoelastic and

Antibacterial BehaviorrdquoMaterials vol 11 no 7 Article ID 1096pp 10961ndash109615 2018

[44] A Kubacka M Ferrer M L Cerrada et al ldquoBoostingTiO2-anatase antimicrobial activity Polymer-oxide thin filmsrdquoApplied Catalysis B Environmental vol 89 no 3-4 pp 441ndash4472009

[45] Y Cheng T Sakai R Moroi et al ldquoSelf-cleaning abilityof a photocatalyst-containing denture base materialrdquo DentalMaterials vol 27 no 2 pp 179ndash186 2008

[46] C M Bollen P Lambrechts and M Quirynen ldquoComparisonof surface roughness of oral hard materials to the thresholdsurface roughness for bacterial plaque retention a review of theliteraturerdquoDental Materials vol 13 no 4 pp 258ndash269 1997

[47] N Elshereksi M Ghazali A Muchtar and C Azhari ldquoEffectof nanobarium titanate addition on the surface characteristicsof denture base resinrdquo International Journal of Mechanical andProduction Engineering vol 5 pp 1ndash8 2017

[48] Y Xia Z Feimin H Xie and N Gu ldquoNanoparticles reinforcedresin based dental compositesrdquo Journal of Dentistry vol 36 pp450ndash455 2008

[49] S Mosalman S Rashahmadi and R Hasanzadeh ldquoThe effectof TiO2 nanoparticles on mechanical properties of poly methylmethacrylate nanocompositesrdquo International Journal of Engi-neering Transactions B Applications vol 30 no 5 pp 807ndash8132017

[50] Y Han S Kiat-amnuay J M Powers and Y Zhao ldquoEffectof nano-oxide concentration on the mechanical properties ofa maxillofacial silicone elastomerrdquo The Journal of ProstheticDentistry vol 100 no 6 pp 465ndash473 2008

[51] I N Safi ldquoEvaluation the effect of nanomdashfillers (TiO2 AL2O3

SiO2) addition on glass transition temperature E-moudulus

and coefficient of thermal expansion of acrylic denture basematerialrdquo Journal of Baghdad College of Dentistry vol 26 no1 pp 37ndash41 2014

[52] W Wang S Liao Y Zhu M Liu Q Zhao and Y Fu ldquoRecentApplications of Nanomaterials in Prosthodonticsrdquo Journal ofNanomaterials vol 2015 Article ID 408643 11 pages 2015

[53] L Sun R F Gibson F Gordaninejad and J Suhr ldquoEnergyabsorption capability of nanocomposites A reviewrdquoCompositesScience and Technology vol 69 no 14 pp 2392ndash2409 2009

[54] S Podzimek K Hana M Miksovsky et al ldquoThe Influence ofgalvanic currents and voltage on the proliferation activity oflymphocytes and expression of cell surface moleculesrdquo FoliaBiologica vol 54 no 5 pp 146ndash150 2008

[55] E E Totu E Voicila V Pistritu G Nechifor and C MCristache ldquoEvaluation of electrical characteristics for PMMA-TiO2 nanocomposites used in dentistryrdquo Evista de Chimie vol69 no 1 pp 155ndash159 2018

CorrosionInternational Journal of

Hindawiwwwhindawicom Volume 2018

Advances in

Materials Science and EngineeringHindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

Journal of

Chemistry

Analytical ChemistryInternational Journal of

Hindawiwwwhindawicom Volume 2018

ScienticaHindawiwwwhindawicom Volume 2018

Polymer ScienceInternational Journal of

Hindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

Advances in Condensed Matter Physics

Hindawiwwwhindawicom Volume 2018

International Journal of

BiomaterialsHindawiwwwhindawicom

Journal ofEngineeringVolume 2018

Applied ChemistryJournal of

Hindawiwwwhindawicom Volume 2018

NanotechnologyHindawiwwwhindawicom Volume 2018

Journal of

Hindawiwwwhindawicom Volume 2018

High Energy PhysicsAdvances in

Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawiwwwhindawicom

The Scientific World Journal

Volume 2018

TribologyAdvances in

Hindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

ChemistryAdvances in

Hindawiwwwhindawicom Volume 2018

Advances inPhysical Chemistry

Hindawiwwwhindawicom Volume 2018

BioMed Research InternationalMaterials

Journal of

Hindawiwwwhindawicom Volume 2018

Na

nom

ate

ria

ls

Hindawiwwwhindawicom Volume 2018

Journal ofNanomaterials

Submit your manuscripts atwwwhindawicom

10 International Journal of Biomaterials

Table1Con

tinued

Authorsyear

Particlesiz

eAd

ditio

npercentage

Type

ofAc

rylic

Nanocom

positep

reparatio

nProp

ertie

stested

Specim

ensiz

eEff

ects

(IncreaseD

ecreaseUnchanged)

Ahm

edetal2016

[19]

46nm

0 10

50

Con

ventionalh

eat

cure

acrylic

resin

(ImplacrylVe

rtex)

andhigh

impact

heatcureacrylic

resin

(Vertex-Dental

Netherla

nds)

(i)TiO2NPwe

readdedinto

acrylic

resin

(i)Flexuralstr

ength

(ii)Impactstr

ength

(iii)Hardn

ess

50x10

x3mm

60x6x4mm

25x10

x3mm

(i)Decreased

with

TiO2

additio

n

(ii)Increased

onlyfor

conventio

nalacrylicresin

mod

ified

by1

(iii)Increasedwith

5additio

nTiO2NPforb

othtypeso

facrylic

Sodagare

tal2016

[20]

21nm

05 10

SelectaP

lus

(self-c

urea

crylic

resin

)

(i)Nanop

artic

lesw

erea

dded

toacrylic

mon

omer

and

stirred

(i)Antim

icrobial

prop

ertie

s20

x20

x1m

m

(i)TiO2redu

cedmicrobial

grow

thatbo

thconcentrations

at90

min

underU

VAexpo

sure

(ii)A

ntim

icrobialactiv

ityof

TiO2istim

edependent

Ahm

edetal2017

[21]

lt25

nm0 05 10

Heatcurea

crylic

resin

from

Dentsp

lyInternationalInc

(ChicagoIL

USA

)

(i)TiO2NPwe

readdedto

acrylic

polymer

andmixed

usingam

algam

capsule

(i)Flexuralstr

ength

(ii)F

racture

toug

hness

(iii)Hardn

ess

65x10

x25mm

65x10

x25mm

30x10

x25mm

(i)Increasedwith

both

filler

percentages

(ii)N

oeffecto

nfracture

toug

hnesso

fbothfiller

percentages

(iii)Increasedwith

1filler

Hashem

etal2

017

[22]

90nm

0 10

20 30

Self-cureacrylic

resin

from

Eco-crylcold

Protechn

o(Spain)

(i)TiO2NPwe

remixed

with

them

onom

er

(i)Flexuralmod

ulus

andflexu

ral

strength

(ii)H

ardn

ess

(iii)Surfa

cewe

tting

30x8x1m

m

50x1m

mdiscs

(i)Increasedlin

early

(ii)Increased

(iii)Re

ducedwith

1filler

contentand

increasedwith

high

erpercentages

(iv)T

gdecreasedwith

TiO2

additio

n

Ghahrem

anietal

2017

[23]

20-30nm

ldquoAnatase

phaserdquo

0 10

SRTriplexHot

heatcureacrylic

resin

(Ivoclar

Vivadent

Inc

Schaan

Liechtenste

in)

(i)TiO2NPwe

remixed

with

acrylic

resin

powd

erin

anultrason

icmixer

(i)Tensile

strength

(ii)Impactstr

ength

60x12

x39mm

75x10

x10

mm

(i)Increased

(ii)Increased

International Journal of Biomaterials 11Ta

ble1Con

tinued

Authorsyear

Particlesiz

eAd

ditio

npercentage

Type

ofAc

rylic

Nanocom

positep

reparatio

nProp

ertie

stested

Specim

ensiz

eEff

ects

(IncreaseD

ecreaseUnchanged)

Totu

etal2017

[24]

65-170

nm

0 02

04 1 25

PMMA+P

EMAfor

3Dprintin

g(eDent

100En

visio

nTec

GmbH

Gladb

eck

Germany)

(i)Nanop

artic

lesw

erea

dded

into

PMMAsolutio

nwith

continuo

usstirringand

ultrason

icmixingfor1

hour

(i)Antim

icrobial

effect(Ca

ndida

scotti)

(ii)C

omplete

denture

manufacturin

gusin

gste

reolith

ograph

y

(i)041

and25

inhibited

cand

idagrow

th

(ii)P

MMA04TiO2compo

site

successfu

llyused

ford

enture

fabrication

Aziz2018

[25]

30nm

0 30

Highim

pactheat

cure

acrylic

resin

(Vertex-Dental

Netherla

nds)-

(i)TiO2NPwe

redispersedin

mon

omer

andsonicatedat

120W

and60

KHzfor

3minutes

(i)Im

pactstr

ength

(ii)C

olor

stability

(iii)Th

ermal

cond

uctiv

ity

80x10

x4mm

35x15

x05mm

40x25mm

(i)Increased

(ii)Increased

colorstabilityfor

testgrou

ps

(iii)Noeffect

Alra

hlah

etal

2018

[26]

80-100

nm

0 1 2 3

Heatcurea

crylic

resin

(Lucito

ne550Dentsp

lyInt

IncPaU

SA)

(i)Hardn

essa

ndmod

ulus

(ii)T

gdegradation

temperatureand

rate

(iii)Cr

eep-recovery

andrelaxatio

nbehavior

(iv)A

ntibacteria

ladhesio

n

50x10

mm

discs

cutindifferent

sizes

ford

ifferent

tests

7mg

5x10

mm

(i)Increased

(ii)S

light

increase

with

2nano

-fillerc

ontent

(iii)Im

provem

entinbehavior

(iv)D

ecreaseinbacterial

attachmentcon

tent

Karcietal2018

[27]

13nm

0 1 3 5

(i)Au

to-polyeriz

ed(H

eraeus

Kulze

rNew

bury

Berkshire

UK)

(ii)

Heat-p

olym

erized

Heraeus

Kulze

rNew

bury

Berkshire

UK

(iii)Microwave-

polymerized

(GC

DentalTo

kyo

Japan)

(i)TiO2NPwe

remixed

with

acrylic

resin

powd

erusing

ballmillingat40

0rpm

for2

hours

(i)Flexuralstr

ength

65x10

x3mm

(i)Increasedforh

eat-and

auto-polym

erized

acrylic

at1

(ii)D

ecreased

fora

lltypeso

facrylic

at5

12 International Journal of Biomaterials

Table1Con

tinued

Authorsyear

Particlesiz

eAd

ditio

npercentage

Type

ofAc

rylic

Nanocom

positep

reparatio

nProp

ertie

stested

Specim

ensiz

eEff

ects

(IncreaseD

ecreaseUnchanged)

Totu

etalTo

tuet

al2

017[28]

ldquoAnatase

phaserdquo

0 02

04

06 10

25

(i)PM

MA-

MA

(ii)P

MMA-

MMA-

BPO

(iii)3D

printed

PMMA(eD

Envisio

nTec

GmbH

Gladb

eck

Germany)

(i)TiO2mod

ified

bymethacrylicacid

then

manually

mixed

with

PMMAmixture

(i)Th

ermalsta

bility

(ii)T

g

Stereolitho

graphic

dentures

(i)Increased(im

proved)

(ii)Increased

Totu

etal2018

[29]

ldquoAnatase

phaserdquo

0 02

04

06 10

20 25 50

PMMAfor3

Dprintin

g(eDent

100En

visio

nTec

GmbH

Gladb

eck

Germany)

(i)Re

sistance

(ii)E

lectric

alcond

uctiv

ity

(iii)Dielectric

constant

(i)Decreased

with

1020

25

and5

(ii)Increased

butm

aterialstill

maintainedinsulatin

gprop

ertie

s

(iii)Increasedwith

5

International Journal of Biomaterials 13

Conflicts of Interest

The authors declare that they have no conflicts of interest

References

[1] R L Sakaguchi and J M Powers Craigrsquos Restorative DentalMaterials Elsevier Health Sciences Philadelphia PA USA pp163-176 2012

[2] N Murakami N Wakabayashi R Matsushima A Kishidaand Y Igarashi ldquoEffect of high-pressure polymerization onmechanical properties of PMMA denture base resinrdquo Journalof the Mechanical Behavior of Biomedical Materials vol 20 pp98ndash104 2013

[3] R Adhikari and G H Michler ldquoPolymer nanocompositescharacterization by microscopyrdquo Polymer Reviews vol 49 no3 pp 141ndash180 2009

[4] A Navidfar T Azdast and A Karimzad Ghavidel ldquoInfluenceof processing condition and carbon nanotube on mechani-cal properties of injection molded multi-walled carbon nan-otubepoly(methyl methacrylate) nanocompositesrdquo Journal ofApplied Polymer Science vol 133 no 31 Article ID 43738 pp1ndash9 2016

[5] P Chaijareenont H Takahashi N Nishiyama and M Ark-sornnukit ldquoEffect of different amounts of 3-methacryloxypro-pyltrimethoxysilane on the flexural properties and wear resis-tance of alumina reinforced PMMArdquo Dental Materials vol 31no 4 pp 623ndash628 2012

[6] J Jordan K I Jacob R TannenbaumMA Sharaf and I JasiukldquoExperimental trends in polymer nanocompositesmdasha reviewrdquoMaterials Science and Engineering A vol 393 no 1-2 pp 1ndash112005

[7] MMGad SM Fouda F A Al-Harbi RNapankangas andARaustia ldquoPMMAdenture base material enhancement A reviewof fiber filler and nanofiller additionrdquo International Journal ofNanomedicine vol 12 pp 3801ndash3812 2017

[8] F Li S Zhou B You and L Wu ldquoKinetic study onthe UV-induced photopolymerization of epoxy acrylateTiO2nanocomposites by FTIR spectroscopyrdquo Journal of AppliedPolymer Science vol 99 no 6 pp 3281ndash3287 2006

[9] A Chatterjee ldquoProperties improvement of PMMA using nanoTiO2rdquo Journal of Applied Polymer Science vol 118 no 5 pp2890ndash2897 2010

[10] P Harini K Mohamed and T V Padmanabhan ldquoEffect ofTitanium dioxide nanoparticles on the flexural strength ofpolymethylmethacrylate An in vitro studyrdquo Indian Journal ofDental Research vol 25 no 4 pp 459ndash463 2014

[11] G Venkatesh Anehosur R D Kulkarni M G Naik et alldquoSynthesis and Determination of Antimicrobial Activity ofVisible Light Activated TiO2 Nanoparticles with PolymethylMethacrylate Denture Base Resin Against StaphylococcusAureusrdquo Journal of Gerontology ampGeriatric Research vol 01 no01 pp 103ndash111 2012

[12] A Sodagar A Bahador S Khalil A Saffar Shahroudi and MZaman Kassaee ldquoThe effect of TiO

2and SiO

2nanoparticles on

flexural strength of poly (methyl methacrylate) acrylic resinsrdquoJournal of Prosthodontic Research vol 57 no 1 pp 15ndash19 2013

[13] I M Hamouda and M M Beyari ldquoAddition of glass fibers andtitanium dioxide nanoparticles to the acrylic resin denture basematerial comparative study with the conventional and highimpact typesrdquo Oral Health and Dental Management vol 13 pp107ndash112 2014

[14] E E Totu C M Cristache E Voicila et al ldquoOn physicaland chemical characteristics of Poly(methylmethacrylate) na-nocomposites for dental applications IrdquoMateriale Plastice vol54 no 4 pp 666ndash672 2017

[15] S Shirkavand and EMoslehifard ldquoEffect of TiO2 nanoparticleson tensile strength of dental acrylic resinsrdquo Journal of DentalResearch Dental Clinics Dental Prospects vol 8 no 4 pp 197ndash203 2014

[16] M Karci N Demir and S Yazman ldquoEvaluation of FlexuralStrength of Different Denture Base Materials Reinforced withDifferent Nanoparticlesrdquo Journal of Prosthodontics 2018

[17] O Gurbuz F Unalan and I Dikbas ldquoComparison of thetransverse strength of six acrylic denture resinsrdquo OhdmbscMagazines vol 9 pp 21ndash24 2010

[18] S A Alwan and S S Alameer ldquoThe Effect of the Addition ofSilanized Nano Titania Fillers on Some Physical and Mechan-ical Properties of Heat Cured Acrylic Denture Base MaterialsrdquoJournal of Baghdad College of Dentistry vol 27 no 1 pp 86ndash912015

[19] M Ashour Ahmed M El-Shennawy Y M Althomali andA A Omar ldquoEffect of Titanium Dioxide Nano Particles In-corporation on Mechanical and Physical Properties on TwoDifferent Types of Acrylic Resin Denture Baserdquo World Journalof Nanoscience and Engineering vol 06 no 03 pp 111ndash119 2016

[20] A Sodagar S Khalil M Z Kassaee A S Shahroudi B Pourak-bari and A Bahador ldquoAntimicrobial properties of poly (methylmethacrylate) acrylic resins incorporated with silicon dioxideand titanium dioxide nanoparticles on cariogenic bacteriardquoJournal of Orthodontic Science vol 5 no 1 pp 7ndash13 2016

[21] M A Ahmed A A Omar M El-Shennawy M I Ebrahimand Y M Althomali ldquoInfluence of addition of different types ofnano-fillers on the microstructure and mechanical propertiesof PMMA based denture resinrdquo Kasmera Journal vol 45 pp48ndash59 2017

[22] MHashemM F Al Rez H Fouad et al ldquoInfluence of titaniumoxide nanoparticles on the physical and thermomechanicalbehavior of poly methyl methacrylate (pmma) A denture baseresinrdquo Science of Advanced Materials vol 9 no 6 pp 938ndash9442017

[23] L Ghahremani S Shirkavand F Akbari and N SabzikarildquoTensile strength and impact strength of color modified acrylicresin reinforcedwith titaniumdioxide nanoparticlesrdquo Journal ofClinical and Experimental Dentistry vol 9 no 5 pp e661ndashe6652017

[24] E E Totu A C Nechifor G Nechifor H Y Aboul-Eneinand C M Cristache ldquoPoly(methyl methacrylate) with TiO2nanoparticles inclusion for stereolitographic complete denturemanufacturing minus the fututre in dental care for elderly edentu-lous patientsrdquo Journal of Dentistry vol 59 pp 68ndash77 2017

[25] H K Aziz ldquoTiO-Nanofillers Effects on Some Properties ofHighly- Impact Resin Using Different Processing TechniquesrdquoThe Open Dentistry Journal vol 12 no 1 pp 202ndash212 2018

[26] M Tsuji T Ueda K Sawaki M Kawaguchi and K SakuraildquoBiocompatibility of a titanium dioxide-coating method fordenture base acrylic resinrdquo Gerodontology vol 33 no 4 pp539ndash544 2016

[27] S PodzimekM Tomka P Sommerova Y Lyuya-Mi J Bartovaand J Prochazkova ldquoImmune markers in oral discomfortpatients before and after elimination of oral galvanismrdquo Neu-roendocrinology Letters vol 34 no 8 pp 802ndash808 2013

[28] S Kiat-amnuayM Beerbower JM Powers andRD ParavinaldquoInfluence of pigments and opacifiers on color stability of

14 International Journal of Biomaterials

siliconemaxillofacial elastomerrdquo Journal ofDentistry vol 37 no1 pp e45ndashe50 2009

[29] S H Tuna F Keyf H O Gumus and C Uzun ldquoThe evaluationof water sorptionsolubility of various acrylic resinsrdquo EuropeanJournal of Dental Education vol 2 pp 191ndash197 2008

[30] S M Khaled R Sui P A Charpentier and A S RizkallaldquoSynthesis of TiO

2-PMMA nanocomposite using methacrylic

acid as a coupling agentrdquo Langmuir vol 23 no 7 pp 3988ndash39952007

[31] L Reijnders ldquoThe release of TiO2 and SiO2 nanoparticles fromnanocompositesrdquo Polymer Degradation and Stability vol 94no 5 pp 873ndash876 2009

[32] G Nazirkar S Bhanushali S Singh B Pattanaik and N RajldquoEffect of Anatase Titanium Dioxide Nanoparticles on theFlexural Strength of Heat Cured Poly Methyl MethacrylateResins An In-Vitro Studyrdquo Journal of Indian ProsthodontistSociety vol 14 pp 144ndash149 2014

[33] A Chatterjee ldquoEffect of nanoTiO2addition on poly(methyl

methacrylate) an exciting nanocompositerdquo Journal of AppliedPolymer Science vol 116 no 6 pp 3396ndash3407 2010

[34] S Rashahmadi R Hasanzadeh and S Mosalman ldquoImprov-ing the Mechanical Properties of Poly Methyl MethacrylateNanocomposites for Dentistry Applications Reinforced withDifferent Nanoparticlesrdquo PolymermdashPlastics Technology andEngineering vol 56 no 16 pp 1730ndash1740 2017

[35] A H Yuwono B Liu J Xue et al ldquoControlling the crystallinityand nonlinear optical properties of transparent TiO

2-PMMA

nanohybridsrdquo Journal of Materials Chemistry vol 14 no 20 pp2978ndash2987 2004

[36] J K Pandey K RaghunathaReddy A P Kumar andR P SinghldquoAn overviewon the degradability of polymer nanocompositesrdquoPolymer Degradation and Stability vol 88 no 2 pp 234ndash2502005

[37] C Tao S Jianping J Weng L Ting and H Xiaozhu ldquoPrepara-tion and properties of PMMATiO2 nanocompositerdquoChemicalReaction Engineering andTechnology vol 23 pp 435ndash440 2007

[38] A H Yuwono J Xue J Wang et al ldquoTransparent nanohybridsof nanocrystalline TiO2 in PMMA with unique nonlinearoptical behaviorrdquo Journal of Materials Chemistry vol 13 no 6pp 1475ndash1479 2003

[39] R Alla K N Raghavendra R Vyas and A KonakanchildquoConventional and contemporary polymers for the fabricationof denture prosthesis Part I overview composition and proper-tiesrdquo International Journal of Applied Dental Sciences vol 1 noPart I pp 82ndash89 2015

[40] C C Trapalis P Keivanidis G Kordas et al ldquoTiO2(Fe3+)nanostructured thin films with antibacterial propertiesrdquo ThinSolid Films vol 433 no 1-2 pp 186ndash190 2003

[41] L S Acosta-Torres L M Lopez-Marın R E Nunez-Anita GHernandez-Padron and V M Castano ldquoBiocompatible Metal-Oxide Nanoparticles Nanotechnology Improvement of Con-ventional Prosthetic Acrylic Resinsrdquo Journal of Nanomaterialsvol 2011 Article ID 941561 8 pages 2011

[42] A Bahador S Khalil B Pourakbari et al ldquoPhotocatalyticEffects of Acrylic Resins Incorporated with Nano-titaniumDioxide on Planktonic and Biofilm Growth of Four CariogenicBacteriardquo Annual Research amp Review in Biology vol 4 no 17pp 2695ndash2708 2014

[43] A Alrahlah H Fouad M Hashem A Niazy and A AlBadahldquoTitanium Oxide (TiO2)Polymethylmethacrylate (PMMA)Denture Base Nanocomposites Mechanical Viscoelastic and

Antibacterial BehaviorrdquoMaterials vol 11 no 7 Article ID 1096pp 10961ndash109615 2018

[44] A Kubacka M Ferrer M L Cerrada et al ldquoBoostingTiO2-anatase antimicrobial activity Polymer-oxide thin filmsrdquoApplied Catalysis B Environmental vol 89 no 3-4 pp 441ndash4472009

[45] Y Cheng T Sakai R Moroi et al ldquoSelf-cleaning abilityof a photocatalyst-containing denture base materialrdquo DentalMaterials vol 27 no 2 pp 179ndash186 2008

[46] C M Bollen P Lambrechts and M Quirynen ldquoComparisonof surface roughness of oral hard materials to the thresholdsurface roughness for bacterial plaque retention a review of theliteraturerdquoDental Materials vol 13 no 4 pp 258ndash269 1997

[47] N Elshereksi M Ghazali A Muchtar and C Azhari ldquoEffectof nanobarium titanate addition on the surface characteristicsof denture base resinrdquo International Journal of Mechanical andProduction Engineering vol 5 pp 1ndash8 2017

[48] Y Xia Z Feimin H Xie and N Gu ldquoNanoparticles reinforcedresin based dental compositesrdquo Journal of Dentistry vol 36 pp450ndash455 2008

[49] S Mosalman S Rashahmadi and R Hasanzadeh ldquoThe effectof TiO2 nanoparticles on mechanical properties of poly methylmethacrylate nanocompositesrdquo International Journal of Engi-neering Transactions B Applications vol 30 no 5 pp 807ndash8132017

[50] Y Han S Kiat-amnuay J M Powers and Y Zhao ldquoEffectof nano-oxide concentration on the mechanical properties ofa maxillofacial silicone elastomerrdquo The Journal of ProstheticDentistry vol 100 no 6 pp 465ndash473 2008

[51] I N Safi ldquoEvaluation the effect of nanomdashfillers (TiO2 AL2O3

SiO2) addition on glass transition temperature E-moudulus

and coefficient of thermal expansion of acrylic denture basematerialrdquo Journal of Baghdad College of Dentistry vol 26 no1 pp 37ndash41 2014

[52] W Wang S Liao Y Zhu M Liu Q Zhao and Y Fu ldquoRecentApplications of Nanomaterials in Prosthodonticsrdquo Journal ofNanomaterials vol 2015 Article ID 408643 11 pages 2015

[53] L Sun R F Gibson F Gordaninejad and J Suhr ldquoEnergyabsorption capability of nanocomposites A reviewrdquoCompositesScience and Technology vol 69 no 14 pp 2392ndash2409 2009

[54] S Podzimek K Hana M Miksovsky et al ldquoThe Influence ofgalvanic currents and voltage on the proliferation activity oflymphocytes and expression of cell surface moleculesrdquo FoliaBiologica vol 54 no 5 pp 146ndash150 2008

[55] E E Totu E Voicila V Pistritu G Nechifor and C MCristache ldquoEvaluation of electrical characteristics for PMMA-TiO2 nanocomposites used in dentistryrdquo Evista de Chimie vol69 no 1 pp 155ndash159 2018

CorrosionInternational Journal of

Hindawiwwwhindawicom Volume 2018

Advances in

Materials Science and EngineeringHindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

Journal of

Chemistry

Analytical ChemistryInternational Journal of

Hindawiwwwhindawicom Volume 2018

ScienticaHindawiwwwhindawicom Volume 2018

Polymer ScienceInternational Journal of

Hindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

Advances in Condensed Matter Physics

Hindawiwwwhindawicom Volume 2018

International Journal of

BiomaterialsHindawiwwwhindawicom

Journal ofEngineeringVolume 2018

Applied ChemistryJournal of

Hindawiwwwhindawicom Volume 2018

NanotechnologyHindawiwwwhindawicom Volume 2018

Journal of

Hindawiwwwhindawicom Volume 2018

High Energy PhysicsAdvances in

Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawiwwwhindawicom

The Scientific World Journal

Volume 2018

TribologyAdvances in

Hindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

ChemistryAdvances in

Hindawiwwwhindawicom Volume 2018

Advances inPhysical Chemistry

Hindawiwwwhindawicom Volume 2018

BioMed Research InternationalMaterials

Journal of

Hindawiwwwhindawicom Volume 2018

Na

nom

ate

ria

ls

Hindawiwwwhindawicom Volume 2018

Journal ofNanomaterials

Submit your manuscripts atwwwhindawicom

International Journal of Biomaterials 11Ta

ble1Con

tinued

Authorsyear

Particlesiz

eAd

ditio

npercentage

Type

ofAc

rylic

Nanocom

positep

reparatio

nProp

ertie

stested

Specim

ensiz

eEff

ects

(IncreaseD

ecreaseUnchanged)

Totu

etal2017

[24]

65-170

nm

0 02

04 1 25

PMMA+P

EMAfor

3Dprintin

g(eDent

100En

visio

nTec

GmbH

Gladb

eck

Germany)

(i)Nanop

artic

lesw

erea

dded

into

PMMAsolutio

nwith

continuo

usstirringand

ultrason

icmixingfor1

hour

(i)Antim

icrobial

effect(Ca

ndida

scotti)

(ii)C

omplete

denture

manufacturin

gusin

gste

reolith

ograph

y

(i)041

and25

inhibited

cand

idagrow

th

(ii)P

MMA04TiO2compo

site

successfu

llyused

ford

enture

fabrication

Aziz2018

[25]

30nm

0 30

Highim

pactheat

cure

acrylic

resin

(Vertex-Dental

Netherla

nds)-

(i)TiO2NPwe

redispersedin

mon

omer

andsonicatedat

120W

and60

KHzfor

3minutes

(i)Im

pactstr

ength

(ii)C

olor

stability

(iii)Th

ermal

cond

uctiv

ity

80x10

x4mm

35x15

x05mm

40x25mm

(i)Increased

(ii)Increased

colorstabilityfor

testgrou

ps

(iii)Noeffect

Alra

hlah

etal

2018

[26]

80-100

nm

0 1 2 3

Heatcurea

crylic

resin

(Lucito

ne550Dentsp

lyInt

IncPaU

SA)

(i)Hardn

essa

ndmod

ulus

(ii)T

gdegradation

temperatureand

rate

(iii)Cr

eep-recovery

andrelaxatio

nbehavior

(iv)A

ntibacteria

ladhesio

n

50x10

mm

discs

cutindifferent

sizes

ford

ifferent

tests

7mg

5x10

mm

(i)Increased

(ii)S

light

increase

with

2nano

-fillerc

ontent

(iii)Im

provem

entinbehavior

(iv)D

ecreaseinbacterial

attachmentcon

tent

Karcietal2018

[27]

13nm

0 1 3 5

(i)Au

to-polyeriz

ed(H

eraeus

Kulze

rNew

bury

Berkshire

UK)

(ii)

Heat-p

olym

erized

Heraeus

Kulze

rNew

bury

Berkshire

UK

(iii)Microwave-

polymerized

(GC

DentalTo

kyo

Japan)

(i)TiO2NPwe

remixed

with

acrylic

resin

powd

erusing

ballmillingat40

0rpm

for2

hours

(i)Flexuralstr

ength

65x10

x3mm

(i)Increasedforh

eat-and

auto-polym

erized

acrylic

at1

(ii)D

ecreased

fora

lltypeso

facrylic

at5

12 International Journal of Biomaterials

Table1Con

tinued

Authorsyear

Particlesiz

eAd

ditio

npercentage

Type

ofAc

rylic

Nanocom

positep

reparatio

nProp

ertie

stested

Specim

ensiz

eEff

ects

(IncreaseD

ecreaseUnchanged)

Totu

etalTo

tuet

al2

017[28]

ldquoAnatase

phaserdquo

0 02

04

06 10

25

(i)PM

MA-

MA

(ii)P

MMA-

MMA-

BPO

(iii)3D

printed

PMMA(eD

Envisio

nTec

GmbH

Gladb

eck

Germany)

(i)TiO2mod

ified

bymethacrylicacid

then

manually

mixed

with

PMMAmixture

(i)Th

ermalsta

bility

(ii)T

g

Stereolitho

graphic

dentures

(i)Increased(im

proved)

(ii)Increased

Totu

etal2018

[29]

ldquoAnatase

phaserdquo

0 02

04

06 10

20 25 50

PMMAfor3

Dprintin

g(eDent

100En

visio

nTec

GmbH

Gladb

eck

Germany)

(i)Re

sistance

(ii)E

lectric

alcond

uctiv

ity

(iii)Dielectric

constant

(i)Decreased

with

1020

25

and5

(ii)Increased

butm

aterialstill

maintainedinsulatin

gprop

ertie

s

(iii)Increasedwith

5

International Journal of Biomaterials 13

Conflicts of Interest

The authors declare that they have no conflicts of interest

References

[1] R L Sakaguchi and J M Powers Craigrsquos Restorative DentalMaterials Elsevier Health Sciences Philadelphia PA USA pp163-176 2012

[2] N Murakami N Wakabayashi R Matsushima A Kishidaand Y Igarashi ldquoEffect of high-pressure polymerization onmechanical properties of PMMA denture base resinrdquo Journalof the Mechanical Behavior of Biomedical Materials vol 20 pp98ndash104 2013

[3] R Adhikari and G H Michler ldquoPolymer nanocompositescharacterization by microscopyrdquo Polymer Reviews vol 49 no3 pp 141ndash180 2009

[4] A Navidfar T Azdast and A Karimzad Ghavidel ldquoInfluenceof processing condition and carbon nanotube on mechani-cal properties of injection molded multi-walled carbon nan-otubepoly(methyl methacrylate) nanocompositesrdquo Journal ofApplied Polymer Science vol 133 no 31 Article ID 43738 pp1ndash9 2016

[5] P Chaijareenont H Takahashi N Nishiyama and M Ark-sornnukit ldquoEffect of different amounts of 3-methacryloxypro-pyltrimethoxysilane on the flexural properties and wear resis-tance of alumina reinforced PMMArdquo Dental Materials vol 31no 4 pp 623ndash628 2012

[6] J Jordan K I Jacob R TannenbaumMA Sharaf and I JasiukldquoExperimental trends in polymer nanocompositesmdasha reviewrdquoMaterials Science and Engineering A vol 393 no 1-2 pp 1ndash112005

[7] MMGad SM Fouda F A Al-Harbi RNapankangas andARaustia ldquoPMMAdenture base material enhancement A reviewof fiber filler and nanofiller additionrdquo International Journal ofNanomedicine vol 12 pp 3801ndash3812 2017

[8] F Li S Zhou B You and L Wu ldquoKinetic study onthe UV-induced photopolymerization of epoxy acrylateTiO2nanocomposites by FTIR spectroscopyrdquo Journal of AppliedPolymer Science vol 99 no 6 pp 3281ndash3287 2006

[9] A Chatterjee ldquoProperties improvement of PMMA using nanoTiO2rdquo Journal of Applied Polymer Science vol 118 no 5 pp2890ndash2897 2010

[10] P Harini K Mohamed and T V Padmanabhan ldquoEffect ofTitanium dioxide nanoparticles on the flexural strength ofpolymethylmethacrylate An in vitro studyrdquo Indian Journal ofDental Research vol 25 no 4 pp 459ndash463 2014

[11] G Venkatesh Anehosur R D Kulkarni M G Naik et alldquoSynthesis and Determination of Antimicrobial Activity ofVisible Light Activated TiO2 Nanoparticles with PolymethylMethacrylate Denture Base Resin Against StaphylococcusAureusrdquo Journal of Gerontology ampGeriatric Research vol 01 no01 pp 103ndash111 2012

[12] A Sodagar A Bahador S Khalil A Saffar Shahroudi and MZaman Kassaee ldquoThe effect of TiO

2and SiO

2nanoparticles on

flexural strength of poly (methyl methacrylate) acrylic resinsrdquoJournal of Prosthodontic Research vol 57 no 1 pp 15ndash19 2013

[13] I M Hamouda and M M Beyari ldquoAddition of glass fibers andtitanium dioxide nanoparticles to the acrylic resin denture basematerial comparative study with the conventional and highimpact typesrdquo Oral Health and Dental Management vol 13 pp107ndash112 2014

[14] E E Totu C M Cristache E Voicila et al ldquoOn physicaland chemical characteristics of Poly(methylmethacrylate) na-nocomposites for dental applications IrdquoMateriale Plastice vol54 no 4 pp 666ndash672 2017

[15] S Shirkavand and EMoslehifard ldquoEffect of TiO2 nanoparticleson tensile strength of dental acrylic resinsrdquo Journal of DentalResearch Dental Clinics Dental Prospects vol 8 no 4 pp 197ndash203 2014

[16] M Karci N Demir and S Yazman ldquoEvaluation of FlexuralStrength of Different Denture Base Materials Reinforced withDifferent Nanoparticlesrdquo Journal of Prosthodontics 2018

[17] O Gurbuz F Unalan and I Dikbas ldquoComparison of thetransverse strength of six acrylic denture resinsrdquo OhdmbscMagazines vol 9 pp 21ndash24 2010

[18] S A Alwan and S S Alameer ldquoThe Effect of the Addition ofSilanized Nano Titania Fillers on Some Physical and Mechan-ical Properties of Heat Cured Acrylic Denture Base MaterialsrdquoJournal of Baghdad College of Dentistry vol 27 no 1 pp 86ndash912015

[19] M Ashour Ahmed M El-Shennawy Y M Althomali andA A Omar ldquoEffect of Titanium Dioxide Nano Particles In-corporation on Mechanical and Physical Properties on TwoDifferent Types of Acrylic Resin Denture Baserdquo World Journalof Nanoscience and Engineering vol 06 no 03 pp 111ndash119 2016

[20] A Sodagar S Khalil M Z Kassaee A S Shahroudi B Pourak-bari and A Bahador ldquoAntimicrobial properties of poly (methylmethacrylate) acrylic resins incorporated with silicon dioxideand titanium dioxide nanoparticles on cariogenic bacteriardquoJournal of Orthodontic Science vol 5 no 1 pp 7ndash13 2016

[21] M A Ahmed A A Omar M El-Shennawy M I Ebrahimand Y M Althomali ldquoInfluence of addition of different types ofnano-fillers on the microstructure and mechanical propertiesof PMMA based denture resinrdquo Kasmera Journal vol 45 pp48ndash59 2017

[22] MHashemM F Al Rez H Fouad et al ldquoInfluence of titaniumoxide nanoparticles on the physical and thermomechanicalbehavior of poly methyl methacrylate (pmma) A denture baseresinrdquo Science of Advanced Materials vol 9 no 6 pp 938ndash9442017

[23] L Ghahremani S Shirkavand F Akbari and N SabzikarildquoTensile strength and impact strength of color modified acrylicresin reinforcedwith titaniumdioxide nanoparticlesrdquo Journal ofClinical and Experimental Dentistry vol 9 no 5 pp e661ndashe6652017

[24] E E Totu A C Nechifor G Nechifor H Y Aboul-Eneinand C M Cristache ldquoPoly(methyl methacrylate) with TiO2nanoparticles inclusion for stereolitographic complete denturemanufacturing minus the fututre in dental care for elderly edentu-lous patientsrdquo Journal of Dentistry vol 59 pp 68ndash77 2017

[25] H K Aziz ldquoTiO-Nanofillers Effects on Some Properties ofHighly- Impact Resin Using Different Processing TechniquesrdquoThe Open Dentistry Journal vol 12 no 1 pp 202ndash212 2018

[26] M Tsuji T Ueda K Sawaki M Kawaguchi and K SakuraildquoBiocompatibility of a titanium dioxide-coating method fordenture base acrylic resinrdquo Gerodontology vol 33 no 4 pp539ndash544 2016

[27] S PodzimekM Tomka P Sommerova Y Lyuya-Mi J Bartovaand J Prochazkova ldquoImmune markers in oral discomfortpatients before and after elimination of oral galvanismrdquo Neu-roendocrinology Letters vol 34 no 8 pp 802ndash808 2013

[28] S Kiat-amnuayM Beerbower JM Powers andRD ParavinaldquoInfluence of pigments and opacifiers on color stability of

14 International Journal of Biomaterials

siliconemaxillofacial elastomerrdquo Journal ofDentistry vol 37 no1 pp e45ndashe50 2009

[29] S H Tuna F Keyf H O Gumus and C Uzun ldquoThe evaluationof water sorptionsolubility of various acrylic resinsrdquo EuropeanJournal of Dental Education vol 2 pp 191ndash197 2008

[30] S M Khaled R Sui P A Charpentier and A S RizkallaldquoSynthesis of TiO

2-PMMA nanocomposite using methacrylic

acid as a coupling agentrdquo Langmuir vol 23 no 7 pp 3988ndash39952007

[31] L Reijnders ldquoThe release of TiO2 and SiO2 nanoparticles fromnanocompositesrdquo Polymer Degradation and Stability vol 94no 5 pp 873ndash876 2009

[32] G Nazirkar S Bhanushali S Singh B Pattanaik and N RajldquoEffect of Anatase Titanium Dioxide Nanoparticles on theFlexural Strength of Heat Cured Poly Methyl MethacrylateResins An In-Vitro Studyrdquo Journal of Indian ProsthodontistSociety vol 14 pp 144ndash149 2014

[33] A Chatterjee ldquoEffect of nanoTiO2addition on poly(methyl

methacrylate) an exciting nanocompositerdquo Journal of AppliedPolymer Science vol 116 no 6 pp 3396ndash3407 2010

[34] S Rashahmadi R Hasanzadeh and S Mosalman ldquoImprov-ing the Mechanical Properties of Poly Methyl MethacrylateNanocomposites for Dentistry Applications Reinforced withDifferent Nanoparticlesrdquo PolymermdashPlastics Technology andEngineering vol 56 no 16 pp 1730ndash1740 2017

[35] A H Yuwono B Liu J Xue et al ldquoControlling the crystallinityand nonlinear optical properties of transparent TiO

2-PMMA

nanohybridsrdquo Journal of Materials Chemistry vol 14 no 20 pp2978ndash2987 2004

[36] J K Pandey K RaghunathaReddy A P Kumar andR P SinghldquoAn overviewon the degradability of polymer nanocompositesrdquoPolymer Degradation and Stability vol 88 no 2 pp 234ndash2502005

[37] C Tao S Jianping J Weng L Ting and H Xiaozhu ldquoPrepara-tion and properties of PMMATiO2 nanocompositerdquoChemicalReaction Engineering andTechnology vol 23 pp 435ndash440 2007

[38] A H Yuwono J Xue J Wang et al ldquoTransparent nanohybridsof nanocrystalline TiO2 in PMMA with unique nonlinearoptical behaviorrdquo Journal of Materials Chemistry vol 13 no 6pp 1475ndash1479 2003

[39] R Alla K N Raghavendra R Vyas and A KonakanchildquoConventional and contemporary polymers for the fabricationof denture prosthesis Part I overview composition and proper-tiesrdquo International Journal of Applied Dental Sciences vol 1 noPart I pp 82ndash89 2015

[40] C C Trapalis P Keivanidis G Kordas et al ldquoTiO2(Fe3+)nanostructured thin films with antibacterial propertiesrdquo ThinSolid Films vol 433 no 1-2 pp 186ndash190 2003

[41] L S Acosta-Torres L M Lopez-Marın R E Nunez-Anita GHernandez-Padron and V M Castano ldquoBiocompatible Metal-Oxide Nanoparticles Nanotechnology Improvement of Con-ventional Prosthetic Acrylic Resinsrdquo Journal of Nanomaterialsvol 2011 Article ID 941561 8 pages 2011

[42] A Bahador S Khalil B Pourakbari et al ldquoPhotocatalyticEffects of Acrylic Resins Incorporated with Nano-titaniumDioxide on Planktonic and Biofilm Growth of Four CariogenicBacteriardquo Annual Research amp Review in Biology vol 4 no 17pp 2695ndash2708 2014

[43] A Alrahlah H Fouad M Hashem A Niazy and A AlBadahldquoTitanium Oxide (TiO2)Polymethylmethacrylate (PMMA)Denture Base Nanocomposites Mechanical Viscoelastic and

Antibacterial BehaviorrdquoMaterials vol 11 no 7 Article ID 1096pp 10961ndash109615 2018

[44] A Kubacka M Ferrer M L Cerrada et al ldquoBoostingTiO2-anatase antimicrobial activity Polymer-oxide thin filmsrdquoApplied Catalysis B Environmental vol 89 no 3-4 pp 441ndash4472009

[45] Y Cheng T Sakai R Moroi et al ldquoSelf-cleaning abilityof a photocatalyst-containing denture base materialrdquo DentalMaterials vol 27 no 2 pp 179ndash186 2008

[46] C M Bollen P Lambrechts and M Quirynen ldquoComparisonof surface roughness of oral hard materials to the thresholdsurface roughness for bacterial plaque retention a review of theliteraturerdquoDental Materials vol 13 no 4 pp 258ndash269 1997

[47] N Elshereksi M Ghazali A Muchtar and C Azhari ldquoEffectof nanobarium titanate addition on the surface characteristicsof denture base resinrdquo International Journal of Mechanical andProduction Engineering vol 5 pp 1ndash8 2017

[48] Y Xia Z Feimin H Xie and N Gu ldquoNanoparticles reinforcedresin based dental compositesrdquo Journal of Dentistry vol 36 pp450ndash455 2008

[49] S Mosalman S Rashahmadi and R Hasanzadeh ldquoThe effectof TiO2 nanoparticles on mechanical properties of poly methylmethacrylate nanocompositesrdquo International Journal of Engi-neering Transactions B Applications vol 30 no 5 pp 807ndash8132017

[50] Y Han S Kiat-amnuay J M Powers and Y Zhao ldquoEffectof nano-oxide concentration on the mechanical properties ofa maxillofacial silicone elastomerrdquo The Journal of ProstheticDentistry vol 100 no 6 pp 465ndash473 2008

[51] I N Safi ldquoEvaluation the effect of nanomdashfillers (TiO2 AL2O3

SiO2) addition on glass transition temperature E-moudulus

and coefficient of thermal expansion of acrylic denture basematerialrdquo Journal of Baghdad College of Dentistry vol 26 no1 pp 37ndash41 2014

[52] W Wang S Liao Y Zhu M Liu Q Zhao and Y Fu ldquoRecentApplications of Nanomaterials in Prosthodonticsrdquo Journal ofNanomaterials vol 2015 Article ID 408643 11 pages 2015

[53] L Sun R F Gibson F Gordaninejad and J Suhr ldquoEnergyabsorption capability of nanocomposites A reviewrdquoCompositesScience and Technology vol 69 no 14 pp 2392ndash2409 2009

[54] S Podzimek K Hana M Miksovsky et al ldquoThe Influence ofgalvanic currents and voltage on the proliferation activity oflymphocytes and expression of cell surface moleculesrdquo FoliaBiologica vol 54 no 5 pp 146ndash150 2008

[55] E E Totu E Voicila V Pistritu G Nechifor and C MCristache ldquoEvaluation of electrical characteristics for PMMA-TiO2 nanocomposites used in dentistryrdquo Evista de Chimie vol69 no 1 pp 155ndash159 2018

CorrosionInternational Journal of

Hindawiwwwhindawicom Volume 2018

Advances in

Materials Science and EngineeringHindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

Journal of

Chemistry

Analytical ChemistryInternational Journal of

Hindawiwwwhindawicom Volume 2018

ScienticaHindawiwwwhindawicom Volume 2018

Polymer ScienceInternational Journal of

Hindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

Advances in Condensed Matter Physics

Hindawiwwwhindawicom Volume 2018

International Journal of

BiomaterialsHindawiwwwhindawicom

Journal ofEngineeringVolume 2018

Applied ChemistryJournal of

Hindawiwwwhindawicom Volume 2018

NanotechnologyHindawiwwwhindawicom Volume 2018

Journal of

Hindawiwwwhindawicom Volume 2018

High Energy PhysicsAdvances in

Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawiwwwhindawicom

The Scientific World Journal

Volume 2018

TribologyAdvances in

Hindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

ChemistryAdvances in

Hindawiwwwhindawicom Volume 2018

Advances inPhysical Chemistry

Hindawiwwwhindawicom Volume 2018

BioMed Research InternationalMaterials

Journal of

Hindawiwwwhindawicom Volume 2018

Na

nom

ate

ria

ls

Hindawiwwwhindawicom Volume 2018

Journal ofNanomaterials

Submit your manuscripts atwwwhindawicom

12 International Journal of Biomaterials

Table1Con

tinued

Authorsyear

Particlesiz

eAd

ditio

npercentage

Type

ofAc

rylic

Nanocom

positep

reparatio

nProp

ertie

stested

Specim

ensiz

eEff

ects

(IncreaseD

ecreaseUnchanged)

Totu

etalTo

tuet

al2

017[28]

ldquoAnatase

phaserdquo

0 02

04

06 10

25

(i)PM

MA-

MA

(ii)P

MMA-

MMA-

BPO

(iii)3D

printed

PMMA(eD

Envisio

nTec

GmbH

Gladb

eck

Germany)

(i)TiO2mod

ified

bymethacrylicacid

then

manually

mixed

with

PMMAmixture

(i)Th

ermalsta

bility

(ii)T

g

Stereolitho

graphic

dentures

(i)Increased(im

proved)

(ii)Increased

Totu

etal2018

[29]

ldquoAnatase

phaserdquo

0 02

04

06 10

20 25 50

PMMAfor3

Dprintin

g(eDent

100En

visio

nTec

GmbH

Gladb

eck

Germany)

(i)Re

sistance

(ii)E

lectric

alcond

uctiv

ity

(iii)Dielectric

constant

(i)Decreased

with

1020

25

and5

(ii)Increased

butm

aterialstill

maintainedinsulatin

gprop

ertie

s

(iii)Increasedwith

5

International Journal of Biomaterials 13

Conflicts of Interest

The authors declare that they have no conflicts of interest

References

[1] R L Sakaguchi and J M Powers Craigrsquos Restorative DentalMaterials Elsevier Health Sciences Philadelphia PA USA pp163-176 2012

[2] N Murakami N Wakabayashi R Matsushima A Kishidaand Y Igarashi ldquoEffect of high-pressure polymerization onmechanical properties of PMMA denture base resinrdquo Journalof the Mechanical Behavior of Biomedical Materials vol 20 pp98ndash104 2013

[3] R Adhikari and G H Michler ldquoPolymer nanocompositescharacterization by microscopyrdquo Polymer Reviews vol 49 no3 pp 141ndash180 2009

[4] A Navidfar T Azdast and A Karimzad Ghavidel ldquoInfluenceof processing condition and carbon nanotube on mechani-cal properties of injection molded multi-walled carbon nan-otubepoly(methyl methacrylate) nanocompositesrdquo Journal ofApplied Polymer Science vol 133 no 31 Article ID 43738 pp1ndash9 2016

[5] P Chaijareenont H Takahashi N Nishiyama and M Ark-sornnukit ldquoEffect of different amounts of 3-methacryloxypro-pyltrimethoxysilane on the flexural properties and wear resis-tance of alumina reinforced PMMArdquo Dental Materials vol 31no 4 pp 623ndash628 2012

[6] J Jordan K I Jacob R TannenbaumMA Sharaf and I JasiukldquoExperimental trends in polymer nanocompositesmdasha reviewrdquoMaterials Science and Engineering A vol 393 no 1-2 pp 1ndash112005

[7] MMGad SM Fouda F A Al-Harbi RNapankangas andARaustia ldquoPMMAdenture base material enhancement A reviewof fiber filler and nanofiller additionrdquo International Journal ofNanomedicine vol 12 pp 3801ndash3812 2017

[8] F Li S Zhou B You and L Wu ldquoKinetic study onthe UV-induced photopolymerization of epoxy acrylateTiO2nanocomposites by FTIR spectroscopyrdquo Journal of AppliedPolymer Science vol 99 no 6 pp 3281ndash3287 2006

[9] A Chatterjee ldquoProperties improvement of PMMA using nanoTiO2rdquo Journal of Applied Polymer Science vol 118 no 5 pp2890ndash2897 2010

[10] P Harini K Mohamed and T V Padmanabhan ldquoEffect ofTitanium dioxide nanoparticles on the flexural strength ofpolymethylmethacrylate An in vitro studyrdquo Indian Journal ofDental Research vol 25 no 4 pp 459ndash463 2014

[11] G Venkatesh Anehosur R D Kulkarni M G Naik et alldquoSynthesis and Determination of Antimicrobial Activity ofVisible Light Activated TiO2 Nanoparticles with PolymethylMethacrylate Denture Base Resin Against StaphylococcusAureusrdquo Journal of Gerontology ampGeriatric Research vol 01 no01 pp 103ndash111 2012

[12] A Sodagar A Bahador S Khalil A Saffar Shahroudi and MZaman Kassaee ldquoThe effect of TiO

2and SiO

2nanoparticles on

flexural strength of poly (methyl methacrylate) acrylic resinsrdquoJournal of Prosthodontic Research vol 57 no 1 pp 15ndash19 2013

[13] I M Hamouda and M M Beyari ldquoAddition of glass fibers andtitanium dioxide nanoparticles to the acrylic resin denture basematerial comparative study with the conventional and highimpact typesrdquo Oral Health and Dental Management vol 13 pp107ndash112 2014

[14] E E Totu C M Cristache E Voicila et al ldquoOn physicaland chemical characteristics of Poly(methylmethacrylate) na-nocomposites for dental applications IrdquoMateriale Plastice vol54 no 4 pp 666ndash672 2017

[15] S Shirkavand and EMoslehifard ldquoEffect of TiO2 nanoparticleson tensile strength of dental acrylic resinsrdquo Journal of DentalResearch Dental Clinics Dental Prospects vol 8 no 4 pp 197ndash203 2014

[16] M Karci N Demir and S Yazman ldquoEvaluation of FlexuralStrength of Different Denture Base Materials Reinforced withDifferent Nanoparticlesrdquo Journal of Prosthodontics 2018

[17] O Gurbuz F Unalan and I Dikbas ldquoComparison of thetransverse strength of six acrylic denture resinsrdquo OhdmbscMagazines vol 9 pp 21ndash24 2010

[18] S A Alwan and S S Alameer ldquoThe Effect of the Addition ofSilanized Nano Titania Fillers on Some Physical and Mechan-ical Properties of Heat Cured Acrylic Denture Base MaterialsrdquoJournal of Baghdad College of Dentistry vol 27 no 1 pp 86ndash912015

[19] M Ashour Ahmed M El-Shennawy Y M Althomali andA A Omar ldquoEffect of Titanium Dioxide Nano Particles In-corporation on Mechanical and Physical Properties on TwoDifferent Types of Acrylic Resin Denture Baserdquo World Journalof Nanoscience and Engineering vol 06 no 03 pp 111ndash119 2016

[20] A Sodagar S Khalil M Z Kassaee A S Shahroudi B Pourak-bari and A Bahador ldquoAntimicrobial properties of poly (methylmethacrylate) acrylic resins incorporated with silicon dioxideand titanium dioxide nanoparticles on cariogenic bacteriardquoJournal of Orthodontic Science vol 5 no 1 pp 7ndash13 2016

[21] M A Ahmed A A Omar M El-Shennawy M I Ebrahimand Y M Althomali ldquoInfluence of addition of different types ofnano-fillers on the microstructure and mechanical propertiesof PMMA based denture resinrdquo Kasmera Journal vol 45 pp48ndash59 2017

[22] MHashemM F Al Rez H Fouad et al ldquoInfluence of titaniumoxide nanoparticles on the physical and thermomechanicalbehavior of poly methyl methacrylate (pmma) A denture baseresinrdquo Science of Advanced Materials vol 9 no 6 pp 938ndash9442017

[23] L Ghahremani S Shirkavand F Akbari and N SabzikarildquoTensile strength and impact strength of color modified acrylicresin reinforcedwith titaniumdioxide nanoparticlesrdquo Journal ofClinical and Experimental Dentistry vol 9 no 5 pp e661ndashe6652017

[24] E E Totu A C Nechifor G Nechifor H Y Aboul-Eneinand C M Cristache ldquoPoly(methyl methacrylate) with TiO2nanoparticles inclusion for stereolitographic complete denturemanufacturing minus the fututre in dental care for elderly edentu-lous patientsrdquo Journal of Dentistry vol 59 pp 68ndash77 2017

[25] H K Aziz ldquoTiO-Nanofillers Effects on Some Properties ofHighly- Impact Resin Using Different Processing TechniquesrdquoThe Open Dentistry Journal vol 12 no 1 pp 202ndash212 2018

[26] M Tsuji T Ueda K Sawaki M Kawaguchi and K SakuraildquoBiocompatibility of a titanium dioxide-coating method fordenture base acrylic resinrdquo Gerodontology vol 33 no 4 pp539ndash544 2016

[27] S PodzimekM Tomka P Sommerova Y Lyuya-Mi J Bartovaand J Prochazkova ldquoImmune markers in oral discomfortpatients before and after elimination of oral galvanismrdquo Neu-roendocrinology Letters vol 34 no 8 pp 802ndash808 2013

[28] S Kiat-amnuayM Beerbower JM Powers andRD ParavinaldquoInfluence of pigments and opacifiers on color stability of

14 International Journal of Biomaterials

siliconemaxillofacial elastomerrdquo Journal ofDentistry vol 37 no1 pp e45ndashe50 2009

[29] S H Tuna F Keyf H O Gumus and C Uzun ldquoThe evaluationof water sorptionsolubility of various acrylic resinsrdquo EuropeanJournal of Dental Education vol 2 pp 191ndash197 2008

[30] S M Khaled R Sui P A Charpentier and A S RizkallaldquoSynthesis of TiO

2-PMMA nanocomposite using methacrylic

acid as a coupling agentrdquo Langmuir vol 23 no 7 pp 3988ndash39952007

[31] L Reijnders ldquoThe release of TiO2 and SiO2 nanoparticles fromnanocompositesrdquo Polymer Degradation and Stability vol 94no 5 pp 873ndash876 2009

[32] G Nazirkar S Bhanushali S Singh B Pattanaik and N RajldquoEffect of Anatase Titanium Dioxide Nanoparticles on theFlexural Strength of Heat Cured Poly Methyl MethacrylateResins An In-Vitro Studyrdquo Journal of Indian ProsthodontistSociety vol 14 pp 144ndash149 2014

[33] A Chatterjee ldquoEffect of nanoTiO2addition on poly(methyl

methacrylate) an exciting nanocompositerdquo Journal of AppliedPolymer Science vol 116 no 6 pp 3396ndash3407 2010

[34] S Rashahmadi R Hasanzadeh and S Mosalman ldquoImprov-ing the Mechanical Properties of Poly Methyl MethacrylateNanocomposites for Dentistry Applications Reinforced withDifferent Nanoparticlesrdquo PolymermdashPlastics Technology andEngineering vol 56 no 16 pp 1730ndash1740 2017

[35] A H Yuwono B Liu J Xue et al ldquoControlling the crystallinityand nonlinear optical properties of transparent TiO

2-PMMA

nanohybridsrdquo Journal of Materials Chemistry vol 14 no 20 pp2978ndash2987 2004

[36] J K Pandey K RaghunathaReddy A P Kumar andR P SinghldquoAn overviewon the degradability of polymer nanocompositesrdquoPolymer Degradation and Stability vol 88 no 2 pp 234ndash2502005

[37] C Tao S Jianping J Weng L Ting and H Xiaozhu ldquoPrepara-tion and properties of PMMATiO2 nanocompositerdquoChemicalReaction Engineering andTechnology vol 23 pp 435ndash440 2007

[38] A H Yuwono J Xue J Wang et al ldquoTransparent nanohybridsof nanocrystalline TiO2 in PMMA with unique nonlinearoptical behaviorrdquo Journal of Materials Chemistry vol 13 no 6pp 1475ndash1479 2003

[39] R Alla K N Raghavendra R Vyas and A KonakanchildquoConventional and contemporary polymers for the fabricationof denture prosthesis Part I overview composition and proper-tiesrdquo International Journal of Applied Dental Sciences vol 1 noPart I pp 82ndash89 2015

[40] C C Trapalis P Keivanidis G Kordas et al ldquoTiO2(Fe3+)nanostructured thin films with antibacterial propertiesrdquo ThinSolid Films vol 433 no 1-2 pp 186ndash190 2003

[41] L S Acosta-Torres L M Lopez-Marın R E Nunez-Anita GHernandez-Padron and V M Castano ldquoBiocompatible Metal-Oxide Nanoparticles Nanotechnology Improvement of Con-ventional Prosthetic Acrylic Resinsrdquo Journal of Nanomaterialsvol 2011 Article ID 941561 8 pages 2011

[42] A Bahador S Khalil B Pourakbari et al ldquoPhotocatalyticEffects of Acrylic Resins Incorporated with Nano-titaniumDioxide on Planktonic and Biofilm Growth of Four CariogenicBacteriardquo Annual Research amp Review in Biology vol 4 no 17pp 2695ndash2708 2014

[43] A Alrahlah H Fouad M Hashem A Niazy and A AlBadahldquoTitanium Oxide (TiO2)Polymethylmethacrylate (PMMA)Denture Base Nanocomposites Mechanical Viscoelastic and

Antibacterial BehaviorrdquoMaterials vol 11 no 7 Article ID 1096pp 10961ndash109615 2018

[44] A Kubacka M Ferrer M L Cerrada et al ldquoBoostingTiO2-anatase antimicrobial activity Polymer-oxide thin filmsrdquoApplied Catalysis B Environmental vol 89 no 3-4 pp 441ndash4472009

[45] Y Cheng T Sakai R Moroi et al ldquoSelf-cleaning abilityof a photocatalyst-containing denture base materialrdquo DentalMaterials vol 27 no 2 pp 179ndash186 2008

[46] C M Bollen P Lambrechts and M Quirynen ldquoComparisonof surface roughness of oral hard materials to the thresholdsurface roughness for bacterial plaque retention a review of theliteraturerdquoDental Materials vol 13 no 4 pp 258ndash269 1997

[47] N Elshereksi M Ghazali A Muchtar and C Azhari ldquoEffectof nanobarium titanate addition on the surface characteristicsof denture base resinrdquo International Journal of Mechanical andProduction Engineering vol 5 pp 1ndash8 2017

[48] Y Xia Z Feimin H Xie and N Gu ldquoNanoparticles reinforcedresin based dental compositesrdquo Journal of Dentistry vol 36 pp450ndash455 2008

[49] S Mosalman S Rashahmadi and R Hasanzadeh ldquoThe effectof TiO2 nanoparticles on mechanical properties of poly methylmethacrylate nanocompositesrdquo International Journal of Engi-neering Transactions B Applications vol 30 no 5 pp 807ndash8132017

[50] Y Han S Kiat-amnuay J M Powers and Y Zhao ldquoEffectof nano-oxide concentration on the mechanical properties ofa maxillofacial silicone elastomerrdquo The Journal of ProstheticDentistry vol 100 no 6 pp 465ndash473 2008

[51] I N Safi ldquoEvaluation the effect of nanomdashfillers (TiO2 AL2O3

SiO2) addition on glass transition temperature E-moudulus

and coefficient of thermal expansion of acrylic denture basematerialrdquo Journal of Baghdad College of Dentistry vol 26 no1 pp 37ndash41 2014

[52] W Wang S Liao Y Zhu M Liu Q Zhao and Y Fu ldquoRecentApplications of Nanomaterials in Prosthodonticsrdquo Journal ofNanomaterials vol 2015 Article ID 408643 11 pages 2015

[53] L Sun R F Gibson F Gordaninejad and J Suhr ldquoEnergyabsorption capability of nanocomposites A reviewrdquoCompositesScience and Technology vol 69 no 14 pp 2392ndash2409 2009

[54] S Podzimek K Hana M Miksovsky et al ldquoThe Influence ofgalvanic currents and voltage on the proliferation activity oflymphocytes and expression of cell surface moleculesrdquo FoliaBiologica vol 54 no 5 pp 146ndash150 2008

[55] E E Totu E Voicila V Pistritu G Nechifor and C MCristache ldquoEvaluation of electrical characteristics for PMMA-TiO2 nanocomposites used in dentistryrdquo Evista de Chimie vol69 no 1 pp 155ndash159 2018

CorrosionInternational Journal of

Hindawiwwwhindawicom Volume 2018

Advances in

Materials Science and EngineeringHindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

Journal of

Chemistry

Analytical ChemistryInternational Journal of

Hindawiwwwhindawicom Volume 2018

ScienticaHindawiwwwhindawicom Volume 2018

Polymer ScienceInternational Journal of

Hindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

Advances in Condensed Matter Physics

Hindawiwwwhindawicom Volume 2018

International Journal of

BiomaterialsHindawiwwwhindawicom

Journal ofEngineeringVolume 2018

Applied ChemistryJournal of

Hindawiwwwhindawicom Volume 2018

NanotechnologyHindawiwwwhindawicom Volume 2018

Journal of

Hindawiwwwhindawicom Volume 2018

High Energy PhysicsAdvances in

Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawiwwwhindawicom

The Scientific World Journal

Volume 2018

TribologyAdvances in

Hindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

ChemistryAdvances in

Hindawiwwwhindawicom Volume 2018

Advances inPhysical Chemistry

Hindawiwwwhindawicom Volume 2018

BioMed Research InternationalMaterials

Journal of

Hindawiwwwhindawicom Volume 2018

Na

nom

ate

ria

ls

Hindawiwwwhindawicom Volume 2018

Journal ofNanomaterials

Submit your manuscripts atwwwhindawicom

International Journal of Biomaterials 13

Conflicts of Interest

The authors declare that they have no conflicts of interest

References

[1] R L Sakaguchi and J M Powers Craigrsquos Restorative DentalMaterials Elsevier Health Sciences Philadelphia PA USA pp163-176 2012

[2] N Murakami N Wakabayashi R Matsushima A Kishidaand Y Igarashi ldquoEffect of high-pressure polymerization onmechanical properties of PMMA denture base resinrdquo Journalof the Mechanical Behavior of Biomedical Materials vol 20 pp98ndash104 2013

[3] R Adhikari and G H Michler ldquoPolymer nanocompositescharacterization by microscopyrdquo Polymer Reviews vol 49 no3 pp 141ndash180 2009

[4] A Navidfar T Azdast and A Karimzad Ghavidel ldquoInfluenceof processing condition and carbon nanotube on mechani-cal properties of injection molded multi-walled carbon nan-otubepoly(methyl methacrylate) nanocompositesrdquo Journal ofApplied Polymer Science vol 133 no 31 Article ID 43738 pp1ndash9 2016

[5] P Chaijareenont H Takahashi N Nishiyama and M Ark-sornnukit ldquoEffect of different amounts of 3-methacryloxypro-pyltrimethoxysilane on the flexural properties and wear resis-tance of alumina reinforced PMMArdquo Dental Materials vol 31no 4 pp 623ndash628 2012

[6] J Jordan K I Jacob R TannenbaumMA Sharaf and I JasiukldquoExperimental trends in polymer nanocompositesmdasha reviewrdquoMaterials Science and Engineering A vol 393 no 1-2 pp 1ndash112005

[7] MMGad SM Fouda F A Al-Harbi RNapankangas andARaustia ldquoPMMAdenture base material enhancement A reviewof fiber filler and nanofiller additionrdquo International Journal ofNanomedicine vol 12 pp 3801ndash3812 2017

[8] F Li S Zhou B You and L Wu ldquoKinetic study onthe UV-induced photopolymerization of epoxy acrylateTiO2nanocomposites by FTIR spectroscopyrdquo Journal of AppliedPolymer Science vol 99 no 6 pp 3281ndash3287 2006

[9] A Chatterjee ldquoProperties improvement of PMMA using nanoTiO2rdquo Journal of Applied Polymer Science vol 118 no 5 pp2890ndash2897 2010

[10] P Harini K Mohamed and T V Padmanabhan ldquoEffect ofTitanium dioxide nanoparticles on the flexural strength ofpolymethylmethacrylate An in vitro studyrdquo Indian Journal ofDental Research vol 25 no 4 pp 459ndash463 2014

[11] G Venkatesh Anehosur R D Kulkarni M G Naik et alldquoSynthesis and Determination of Antimicrobial Activity ofVisible Light Activated TiO2 Nanoparticles with PolymethylMethacrylate Denture Base Resin Against StaphylococcusAureusrdquo Journal of Gerontology ampGeriatric Research vol 01 no01 pp 103ndash111 2012

[12] A Sodagar A Bahador S Khalil A Saffar Shahroudi and MZaman Kassaee ldquoThe effect of TiO

2and SiO

2nanoparticles on

flexural strength of poly (methyl methacrylate) acrylic resinsrdquoJournal of Prosthodontic Research vol 57 no 1 pp 15ndash19 2013

[13] I M Hamouda and M M Beyari ldquoAddition of glass fibers andtitanium dioxide nanoparticles to the acrylic resin denture basematerial comparative study with the conventional and highimpact typesrdquo Oral Health and Dental Management vol 13 pp107ndash112 2014

[14] E E Totu C M Cristache E Voicila et al ldquoOn physicaland chemical characteristics of Poly(methylmethacrylate) na-nocomposites for dental applications IrdquoMateriale Plastice vol54 no 4 pp 666ndash672 2017

[15] S Shirkavand and EMoslehifard ldquoEffect of TiO2 nanoparticleson tensile strength of dental acrylic resinsrdquo Journal of DentalResearch Dental Clinics Dental Prospects vol 8 no 4 pp 197ndash203 2014

[16] M Karci N Demir and S Yazman ldquoEvaluation of FlexuralStrength of Different Denture Base Materials Reinforced withDifferent Nanoparticlesrdquo Journal of Prosthodontics 2018

[17] O Gurbuz F Unalan and I Dikbas ldquoComparison of thetransverse strength of six acrylic denture resinsrdquo OhdmbscMagazines vol 9 pp 21ndash24 2010

[18] S A Alwan and S S Alameer ldquoThe Effect of the Addition ofSilanized Nano Titania Fillers on Some Physical and Mechan-ical Properties of Heat Cured Acrylic Denture Base MaterialsrdquoJournal of Baghdad College of Dentistry vol 27 no 1 pp 86ndash912015

[19] M Ashour Ahmed M El-Shennawy Y M Althomali andA A Omar ldquoEffect of Titanium Dioxide Nano Particles In-corporation on Mechanical and Physical Properties on TwoDifferent Types of Acrylic Resin Denture Baserdquo World Journalof Nanoscience and Engineering vol 06 no 03 pp 111ndash119 2016

[20] A Sodagar S Khalil M Z Kassaee A S Shahroudi B Pourak-bari and A Bahador ldquoAntimicrobial properties of poly (methylmethacrylate) acrylic resins incorporated with silicon dioxideand titanium dioxide nanoparticles on cariogenic bacteriardquoJournal of Orthodontic Science vol 5 no 1 pp 7ndash13 2016

[21] M A Ahmed A A Omar M El-Shennawy M I Ebrahimand Y M Althomali ldquoInfluence of addition of different types ofnano-fillers on the microstructure and mechanical propertiesof PMMA based denture resinrdquo Kasmera Journal vol 45 pp48ndash59 2017

[22] MHashemM F Al Rez H Fouad et al ldquoInfluence of titaniumoxide nanoparticles on the physical and thermomechanicalbehavior of poly methyl methacrylate (pmma) A denture baseresinrdquo Science of Advanced Materials vol 9 no 6 pp 938ndash9442017

[23] L Ghahremani S Shirkavand F Akbari and N SabzikarildquoTensile strength and impact strength of color modified acrylicresin reinforcedwith titaniumdioxide nanoparticlesrdquo Journal ofClinical and Experimental Dentistry vol 9 no 5 pp e661ndashe6652017

[24] E E Totu A C Nechifor G Nechifor H Y Aboul-Eneinand C M Cristache ldquoPoly(methyl methacrylate) with TiO2nanoparticles inclusion for stereolitographic complete denturemanufacturing minus the fututre in dental care for elderly edentu-lous patientsrdquo Journal of Dentistry vol 59 pp 68ndash77 2017

[25] H K Aziz ldquoTiO-Nanofillers Effects on Some Properties ofHighly- Impact Resin Using Different Processing TechniquesrdquoThe Open Dentistry Journal vol 12 no 1 pp 202ndash212 2018

[26] M Tsuji T Ueda K Sawaki M Kawaguchi and K SakuraildquoBiocompatibility of a titanium dioxide-coating method fordenture base acrylic resinrdquo Gerodontology vol 33 no 4 pp539ndash544 2016

[27] S PodzimekM Tomka P Sommerova Y Lyuya-Mi J Bartovaand J Prochazkova ldquoImmune markers in oral discomfortpatients before and after elimination of oral galvanismrdquo Neu-roendocrinology Letters vol 34 no 8 pp 802ndash808 2013

[28] S Kiat-amnuayM Beerbower JM Powers andRD ParavinaldquoInfluence of pigments and opacifiers on color stability of

14 International Journal of Biomaterials

siliconemaxillofacial elastomerrdquo Journal ofDentistry vol 37 no1 pp e45ndashe50 2009

[29] S H Tuna F Keyf H O Gumus and C Uzun ldquoThe evaluationof water sorptionsolubility of various acrylic resinsrdquo EuropeanJournal of Dental Education vol 2 pp 191ndash197 2008

[30] S M Khaled R Sui P A Charpentier and A S RizkallaldquoSynthesis of TiO

2-PMMA nanocomposite using methacrylic

acid as a coupling agentrdquo Langmuir vol 23 no 7 pp 3988ndash39952007

[31] L Reijnders ldquoThe release of TiO2 and SiO2 nanoparticles fromnanocompositesrdquo Polymer Degradation and Stability vol 94no 5 pp 873ndash876 2009

[32] G Nazirkar S Bhanushali S Singh B Pattanaik and N RajldquoEffect of Anatase Titanium Dioxide Nanoparticles on theFlexural Strength of Heat Cured Poly Methyl MethacrylateResins An In-Vitro Studyrdquo Journal of Indian ProsthodontistSociety vol 14 pp 144ndash149 2014

[33] A Chatterjee ldquoEffect of nanoTiO2addition on poly(methyl

methacrylate) an exciting nanocompositerdquo Journal of AppliedPolymer Science vol 116 no 6 pp 3396ndash3407 2010

[34] S Rashahmadi R Hasanzadeh and S Mosalman ldquoImprov-ing the Mechanical Properties of Poly Methyl MethacrylateNanocomposites for Dentistry Applications Reinforced withDifferent Nanoparticlesrdquo PolymermdashPlastics Technology andEngineering vol 56 no 16 pp 1730ndash1740 2017

[35] A H Yuwono B Liu J Xue et al ldquoControlling the crystallinityand nonlinear optical properties of transparent TiO

2-PMMA

nanohybridsrdquo Journal of Materials Chemistry vol 14 no 20 pp2978ndash2987 2004

[36] J K Pandey K RaghunathaReddy A P Kumar andR P SinghldquoAn overviewon the degradability of polymer nanocompositesrdquoPolymer Degradation and Stability vol 88 no 2 pp 234ndash2502005

[37] C Tao S Jianping J Weng L Ting and H Xiaozhu ldquoPrepara-tion and properties of PMMATiO2 nanocompositerdquoChemicalReaction Engineering andTechnology vol 23 pp 435ndash440 2007

[38] A H Yuwono J Xue J Wang et al ldquoTransparent nanohybridsof nanocrystalline TiO2 in PMMA with unique nonlinearoptical behaviorrdquo Journal of Materials Chemistry vol 13 no 6pp 1475ndash1479 2003

[39] R Alla K N Raghavendra R Vyas and A KonakanchildquoConventional and contemporary polymers for the fabricationof denture prosthesis Part I overview composition and proper-tiesrdquo International Journal of Applied Dental Sciences vol 1 noPart I pp 82ndash89 2015

[40] C C Trapalis P Keivanidis G Kordas et al ldquoTiO2(Fe3+)nanostructured thin films with antibacterial propertiesrdquo ThinSolid Films vol 433 no 1-2 pp 186ndash190 2003

[41] L S Acosta-Torres L M Lopez-Marın R E Nunez-Anita GHernandez-Padron and V M Castano ldquoBiocompatible Metal-Oxide Nanoparticles Nanotechnology Improvement of Con-ventional Prosthetic Acrylic Resinsrdquo Journal of Nanomaterialsvol 2011 Article ID 941561 8 pages 2011

[42] A Bahador S Khalil B Pourakbari et al ldquoPhotocatalyticEffects of Acrylic Resins Incorporated with Nano-titaniumDioxide on Planktonic and Biofilm Growth of Four CariogenicBacteriardquo Annual Research amp Review in Biology vol 4 no 17pp 2695ndash2708 2014

[43] A Alrahlah H Fouad M Hashem A Niazy and A AlBadahldquoTitanium Oxide (TiO2)Polymethylmethacrylate (PMMA)Denture Base Nanocomposites Mechanical Viscoelastic and

Antibacterial BehaviorrdquoMaterials vol 11 no 7 Article ID 1096pp 10961ndash109615 2018

[44] A Kubacka M Ferrer M L Cerrada et al ldquoBoostingTiO2-anatase antimicrobial activity Polymer-oxide thin filmsrdquoApplied Catalysis B Environmental vol 89 no 3-4 pp 441ndash4472009

[45] Y Cheng T Sakai R Moroi et al ldquoSelf-cleaning abilityof a photocatalyst-containing denture base materialrdquo DentalMaterials vol 27 no 2 pp 179ndash186 2008

[46] C M Bollen P Lambrechts and M Quirynen ldquoComparisonof surface roughness of oral hard materials to the thresholdsurface roughness for bacterial plaque retention a review of theliteraturerdquoDental Materials vol 13 no 4 pp 258ndash269 1997

[47] N Elshereksi M Ghazali A Muchtar and C Azhari ldquoEffectof nanobarium titanate addition on the surface characteristicsof denture base resinrdquo International Journal of Mechanical andProduction Engineering vol 5 pp 1ndash8 2017

[48] Y Xia Z Feimin H Xie and N Gu ldquoNanoparticles reinforcedresin based dental compositesrdquo Journal of Dentistry vol 36 pp450ndash455 2008

[49] S Mosalman S Rashahmadi and R Hasanzadeh ldquoThe effectof TiO2 nanoparticles on mechanical properties of poly methylmethacrylate nanocompositesrdquo International Journal of Engi-neering Transactions B Applications vol 30 no 5 pp 807ndash8132017

[50] Y Han S Kiat-amnuay J M Powers and Y Zhao ldquoEffectof nano-oxide concentration on the mechanical properties ofa maxillofacial silicone elastomerrdquo The Journal of ProstheticDentistry vol 100 no 6 pp 465ndash473 2008

[51] I N Safi ldquoEvaluation the effect of nanomdashfillers (TiO2 AL2O3

SiO2) addition on glass transition temperature E-moudulus

and coefficient of thermal expansion of acrylic denture basematerialrdquo Journal of Baghdad College of Dentistry vol 26 no1 pp 37ndash41 2014

[52] W Wang S Liao Y Zhu M Liu Q Zhao and Y Fu ldquoRecentApplications of Nanomaterials in Prosthodonticsrdquo Journal ofNanomaterials vol 2015 Article ID 408643 11 pages 2015

[53] L Sun R F Gibson F Gordaninejad and J Suhr ldquoEnergyabsorption capability of nanocomposites A reviewrdquoCompositesScience and Technology vol 69 no 14 pp 2392ndash2409 2009

[54] S Podzimek K Hana M Miksovsky et al ldquoThe Influence ofgalvanic currents and voltage on the proliferation activity oflymphocytes and expression of cell surface moleculesrdquo FoliaBiologica vol 54 no 5 pp 146ndash150 2008

[55] E E Totu E Voicila V Pistritu G Nechifor and C MCristache ldquoEvaluation of electrical characteristics for PMMA-TiO2 nanocomposites used in dentistryrdquo Evista de Chimie vol69 no 1 pp 155ndash159 2018

CorrosionInternational Journal of

Hindawiwwwhindawicom Volume 2018

Advances in

Materials Science and EngineeringHindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

Journal of

Chemistry

Analytical ChemistryInternational Journal of

Hindawiwwwhindawicom Volume 2018

ScienticaHindawiwwwhindawicom Volume 2018

Polymer ScienceInternational Journal of

Hindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

Advances in Condensed Matter Physics

Hindawiwwwhindawicom Volume 2018

International Journal of

BiomaterialsHindawiwwwhindawicom

Journal ofEngineeringVolume 2018

Applied ChemistryJournal of

Hindawiwwwhindawicom Volume 2018

NanotechnologyHindawiwwwhindawicom Volume 2018

Journal of

Hindawiwwwhindawicom Volume 2018

High Energy PhysicsAdvances in

Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawiwwwhindawicom

The Scientific World Journal

Volume 2018

TribologyAdvances in

Hindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

ChemistryAdvances in

Hindawiwwwhindawicom Volume 2018

Advances inPhysical Chemistry

Hindawiwwwhindawicom Volume 2018

BioMed Research InternationalMaterials

Journal of

Hindawiwwwhindawicom Volume 2018

Na

nom

ate

ria

ls

Hindawiwwwhindawicom Volume 2018

Journal ofNanomaterials

Submit your manuscripts atwwwhindawicom

14 International Journal of Biomaterials

siliconemaxillofacial elastomerrdquo Journal ofDentistry vol 37 no1 pp e45ndashe50 2009

[29] S H Tuna F Keyf H O Gumus and C Uzun ldquoThe evaluationof water sorptionsolubility of various acrylic resinsrdquo EuropeanJournal of Dental Education vol 2 pp 191ndash197 2008

[30] S M Khaled R Sui P A Charpentier and A S RizkallaldquoSynthesis of TiO

2-PMMA nanocomposite using methacrylic

acid as a coupling agentrdquo Langmuir vol 23 no 7 pp 3988ndash39952007

[31] L Reijnders ldquoThe release of TiO2 and SiO2 nanoparticles fromnanocompositesrdquo Polymer Degradation and Stability vol 94no 5 pp 873ndash876 2009

[32] G Nazirkar S Bhanushali S Singh B Pattanaik and N RajldquoEffect of Anatase Titanium Dioxide Nanoparticles on theFlexural Strength of Heat Cured Poly Methyl MethacrylateResins An In-Vitro Studyrdquo Journal of Indian ProsthodontistSociety vol 14 pp 144ndash149 2014

[33] A Chatterjee ldquoEffect of nanoTiO2addition on poly(methyl

methacrylate) an exciting nanocompositerdquo Journal of AppliedPolymer Science vol 116 no 6 pp 3396ndash3407 2010

[34] S Rashahmadi R Hasanzadeh and S Mosalman ldquoImprov-ing the Mechanical Properties of Poly Methyl MethacrylateNanocomposites for Dentistry Applications Reinforced withDifferent Nanoparticlesrdquo PolymermdashPlastics Technology andEngineering vol 56 no 16 pp 1730ndash1740 2017

[35] A H Yuwono B Liu J Xue et al ldquoControlling the crystallinityand nonlinear optical properties of transparent TiO

2-PMMA

nanohybridsrdquo Journal of Materials Chemistry vol 14 no 20 pp2978ndash2987 2004

[36] J K Pandey K RaghunathaReddy A P Kumar andR P SinghldquoAn overviewon the degradability of polymer nanocompositesrdquoPolymer Degradation and Stability vol 88 no 2 pp 234ndash2502005

[37] C Tao S Jianping J Weng L Ting and H Xiaozhu ldquoPrepara-tion and properties of PMMATiO2 nanocompositerdquoChemicalReaction Engineering andTechnology vol 23 pp 435ndash440 2007

[38] A H Yuwono J Xue J Wang et al ldquoTransparent nanohybridsof nanocrystalline TiO2 in PMMA with unique nonlinearoptical behaviorrdquo Journal of Materials Chemistry vol 13 no 6pp 1475ndash1479 2003

[39] R Alla K N Raghavendra R Vyas and A KonakanchildquoConventional and contemporary polymers for the fabricationof denture prosthesis Part I overview composition and proper-tiesrdquo International Journal of Applied Dental Sciences vol 1 noPart I pp 82ndash89 2015

[40] C C Trapalis P Keivanidis G Kordas et al ldquoTiO2(Fe3+)nanostructured thin films with antibacterial propertiesrdquo ThinSolid Films vol 433 no 1-2 pp 186ndash190 2003

[41] L S Acosta-Torres L M Lopez-Marın R E Nunez-Anita GHernandez-Padron and V M Castano ldquoBiocompatible Metal-Oxide Nanoparticles Nanotechnology Improvement of Con-ventional Prosthetic Acrylic Resinsrdquo Journal of Nanomaterialsvol 2011 Article ID 941561 8 pages 2011

[42] A Bahador S Khalil B Pourakbari et al ldquoPhotocatalyticEffects of Acrylic Resins Incorporated with Nano-titaniumDioxide on Planktonic and Biofilm Growth of Four CariogenicBacteriardquo Annual Research amp Review in Biology vol 4 no 17pp 2695ndash2708 2014

[43] A Alrahlah H Fouad M Hashem A Niazy and A AlBadahldquoTitanium Oxide (TiO2)Polymethylmethacrylate (PMMA)Denture Base Nanocomposites Mechanical Viscoelastic and

Antibacterial BehaviorrdquoMaterials vol 11 no 7 Article ID 1096pp 10961ndash109615 2018

[44] A Kubacka M Ferrer M L Cerrada et al ldquoBoostingTiO2-anatase antimicrobial activity Polymer-oxide thin filmsrdquoApplied Catalysis B Environmental vol 89 no 3-4 pp 441ndash4472009

[45] Y Cheng T Sakai R Moroi et al ldquoSelf-cleaning abilityof a photocatalyst-containing denture base materialrdquo DentalMaterials vol 27 no 2 pp 179ndash186 2008

[46] C M Bollen P Lambrechts and M Quirynen ldquoComparisonof surface roughness of oral hard materials to the thresholdsurface roughness for bacterial plaque retention a review of theliteraturerdquoDental Materials vol 13 no 4 pp 258ndash269 1997

[47] N Elshereksi M Ghazali A Muchtar and C Azhari ldquoEffectof nanobarium titanate addition on the surface characteristicsof denture base resinrdquo International Journal of Mechanical andProduction Engineering vol 5 pp 1ndash8 2017

[48] Y Xia Z Feimin H Xie and N Gu ldquoNanoparticles reinforcedresin based dental compositesrdquo Journal of Dentistry vol 36 pp450ndash455 2008

[49] S Mosalman S Rashahmadi and R Hasanzadeh ldquoThe effectof TiO2 nanoparticles on mechanical properties of poly methylmethacrylate nanocompositesrdquo International Journal of Engi-neering Transactions B Applications vol 30 no 5 pp 807ndash8132017

[50] Y Han S Kiat-amnuay J M Powers and Y Zhao ldquoEffectof nano-oxide concentration on the mechanical properties ofa maxillofacial silicone elastomerrdquo The Journal of ProstheticDentistry vol 100 no 6 pp 465ndash473 2008

[51] I N Safi ldquoEvaluation the effect of nanomdashfillers (TiO2 AL2O3

SiO2) addition on glass transition temperature E-moudulus

and coefficient of thermal expansion of acrylic denture basematerialrdquo Journal of Baghdad College of Dentistry vol 26 no1 pp 37ndash41 2014

[52] W Wang S Liao Y Zhu M Liu Q Zhao and Y Fu ldquoRecentApplications of Nanomaterials in Prosthodonticsrdquo Journal ofNanomaterials vol 2015 Article ID 408643 11 pages 2015

[53] L Sun R F Gibson F Gordaninejad and J Suhr ldquoEnergyabsorption capability of nanocomposites A reviewrdquoCompositesScience and Technology vol 69 no 14 pp 2392ndash2409 2009

[54] S Podzimek K Hana M Miksovsky et al ldquoThe Influence ofgalvanic currents and voltage on the proliferation activity oflymphocytes and expression of cell surface moleculesrdquo FoliaBiologica vol 54 no 5 pp 146ndash150 2008

[55] E E Totu E Voicila V Pistritu G Nechifor and C MCristache ldquoEvaluation of electrical characteristics for PMMA-TiO2 nanocomposites used in dentistryrdquo Evista de Chimie vol69 no 1 pp 155ndash159 2018

CorrosionInternational Journal of

Hindawiwwwhindawicom Volume 2018

Advances in

Materials Science and EngineeringHindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

Journal of

Chemistry

Analytical ChemistryInternational Journal of

Hindawiwwwhindawicom Volume 2018

ScienticaHindawiwwwhindawicom Volume 2018

Polymer ScienceInternational Journal of

Hindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

Advances in Condensed Matter Physics

Hindawiwwwhindawicom Volume 2018

International Journal of

BiomaterialsHindawiwwwhindawicom

Journal ofEngineeringVolume 2018

Applied ChemistryJournal of

Hindawiwwwhindawicom Volume 2018

NanotechnologyHindawiwwwhindawicom Volume 2018

Journal of

Hindawiwwwhindawicom Volume 2018

High Energy PhysicsAdvances in

Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawiwwwhindawicom

The Scientific World Journal

Volume 2018

TribologyAdvances in

Hindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

ChemistryAdvances in

Hindawiwwwhindawicom Volume 2018

Advances inPhysical Chemistry

Hindawiwwwhindawicom Volume 2018

BioMed Research InternationalMaterials

Journal of

Hindawiwwwhindawicom Volume 2018

Na

nom

ate

ria

ls

Hindawiwwwhindawicom Volume 2018

Journal ofNanomaterials

Submit your manuscripts atwwwhindawicom

CorrosionInternational Journal of

Hindawiwwwhindawicom Volume 2018

Advances in

Materials Science and EngineeringHindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

Journal of

Chemistry

Analytical ChemistryInternational Journal of

Hindawiwwwhindawicom Volume 2018

ScienticaHindawiwwwhindawicom Volume 2018

Polymer ScienceInternational Journal of

Hindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

Advances in Condensed Matter Physics

Hindawiwwwhindawicom Volume 2018

International Journal of

BiomaterialsHindawiwwwhindawicom

Journal ofEngineeringVolume 2018

Applied ChemistryJournal of

Hindawiwwwhindawicom Volume 2018

NanotechnologyHindawiwwwhindawicom Volume 2018

Journal of

Hindawiwwwhindawicom Volume 2018

High Energy PhysicsAdvances in

Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawiwwwhindawicom

The Scientific World Journal

Volume 2018

TribologyAdvances in

Hindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

ChemistryAdvances in

Hindawiwwwhindawicom Volume 2018

Advances inPhysical Chemistry

Hindawiwwwhindawicom Volume 2018

BioMed Research InternationalMaterials

Journal of

Hindawiwwwhindawicom Volume 2018

Na

nom

ate

ria

ls

Hindawiwwwhindawicom Volume 2018

Journal ofNanomaterials

Submit your manuscripts atwwwhindawicom