Color stability of infiltrant resin exposed to different staining solutions
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e34 dental materials 29S (2013) e1–e96 (n = 10). The control group remained untreated, while the experimental groups were tested for 3 HP concentrations (10%, 35% and 50%). The solutions were applied, respec- tively, every 30min to the enamel, and they were analyzed after each application. The MC of the enamel was deter- mined before and after the bleaching using Fourier transform (FT-Raman) spectroscopy and micro energy-dispersive X-ray fluorescence spectrometry (EDXRF). The calcium (Ca) lost from the bleached enamel was quantified with an atomic absorption spectrometer (AAS). The data were statistically analyzed by the ANOVA, Tukey and Dunnett’s test (p = 0.05). Results: The FT-Raman showed a decrease in MC for all bleaching treatments, without influence of the three different concentrations of HP or the number of applications. EDXRF did not detect any changes in MC. Conclusion: Ca loss was observed by the AAS, with no dif- ference among the 3 HP concentrations. The FT-Raman and AAS analysis detected reduction of MC and Ca loss after HP bleaching. http://dx.doi.org/10.1016/j.dental.2013.08.071 71 Color stability of infiltrant resin exposed to different staining solutions A.B. Borges ∗ , T.M.F. Caneppele, M.A. Luz, C.R. Pucci, C.R.G. Torres University Estadual Paulista – UNESP, Brazil Purpose: The aim of this study was to investigate the stain- ing behavior of the demineralized enamel infiltrated by low viscosity resin. Methods and materials: Bovine enamel cylindrical sam- ples (3 mm × 2 mm) were assigned into four groups (n = 45) according to the treatment: sound enamel (control), white spot lesion (WSL) + artificial saliva, WSL + daily application of 0.05% NaF, WSL + resin infiltration (Icon ® , DMG). Artificial WSL were produced in groups with demineralization. After treatments, color was assessed by spectrophotometry, using CIE L*a*b* sys- tem. The specimens (n = 15) were then immersed in deionized water, red wine or coffee for 10min daily during 8 days. Color was measured again and the specimens were repolished with sandpaper discs. The final color was assessed. Data were ana- lyzed by two-way ANOVA and Tukey tests (a = 0.05). Paired t-test was used for comparison between staining and repol- ishing conditions. Results: The results are presented in the table. Conclusion: The exposure of specimens to colored solu- tions resulted in significant color alteration. The white spot lesions treated with resin infiltration showed significantly higher staining than all other tested groups, however, repol- ishing of the specimens minimized the staining effect. Groups Sound enamel White spot lesion + AS White spot lesion + DF White spot lesion + RI E a E2 b E1 a E2 b E1 a E2 b E1 a E2 b Water 2.4 (1.3)a 2.2 (0.9)AB 2.9 (1.6)a 2.0 (1.3)AB 2.7 (2.2)a 1.6 (1.8)A 2.3 (1.7)a 2.1 (0.9)AB Wine 14.4 (4.2) c cd 10.1 (2.2) c C 11.1 (5.1) c bc 9.3 (5.4) c C 14.2 (2.7) c cd 8.4 (3.2) c C 17.3 (2.7) c de 14.7 (4.7) c D Coffee 14.5 (4.4)cd 8.1 (4.5) c C 9.5 (5.9) c b 8.4 (5.7) c C 7.3 (2.3) c b 6.0 (1.4) c BC 21.3 (4.3) c e 16.6 (4.3) c D a Different lower case letters mean significant differences among the groups for E1(p < 0.05). b Different capital letters mean significant differences among the groups for E2(p < 0.05). c Significant difference between E1 and E2 for each substrate con- dition, using paired t-test (p < 0.05). http://dx.doi.org/10.1016/j.dental.2013.08.072 72 Multiwalled carbon nanotube/nylon-6 nanofiber-reinforced dental composite A.L.S. Borges 1,∗ , A.C. Souza 1 , T.J.A. Paes Junior 1 , T. Yoshida 2 , M.C. Bottino 2 1 University Est. Paulista – UNESP, Sao Jose Dos Campos, Brazil 2 Indiana University, IN, USA Purpose: The aims of this study were (1) to synthe- size/characterize both random and aligned multiwalled carbon nanotubes/nylon-6 (MWCNT/N6) nanofibers and (2) to determine the effect of nanofiber incorporation on the flexural strength (FS) of a dental composite (C). Methods and materials: MWCNT were functionalized (MWCNT) using 12N HCl for 5 min, washed in DI water and dried for 24 h at RT. N6 was dissolved at 10% in hexafluoro-2-propanol. Then, two distinct MWCNT concen- trations (0.5 and 1.5 wt.%) were added to the N6 solution, stirred overnight and sonicated before use. N6 nanofibers both non-aligned/NA and aligned/A with and without MWCNT were processed via electrospinning, as follows: G1-N6/NA, G2- N6/A, G3-N6/NA + 0.5%MWCNT, G4-N6/NA + 1.5%MWCNT, G5- N6/A + 0.5%MWCNT and G6-N6/A + 1.5%MWCNT. Morpholog- ical (SEM/TEM), chemical, and mechanical (tensile strength, TS), studies were carried out after vacuum drying nanofibers at RT for 2 days. Nanofiber sheets (2 mm × 2 mm × 20 mm), of all groups, were cut and used to prepare the composite (GrandioSO ® -VOCO) specimens (n = 6) for flexural testing. Data were analyzed by ANOVA 2-way and Tukey’s test (5%). Results: G2(18.4 ± 2.3 MPa) and G5(19.7 ± 2.5 MPa) showed significantly higher tensile strength than G1(5.8 ± 1.8 MPa) regardless the MWCNT content (Table). The incorporation of the synthesized nanocomposites fibers enhanced significantly the composite flexural strength (Table) when compared to the control (without MWCNT) with better results associated with aligned N6 + 0.5% MWCNT nanofibers (G5 = 142.3 ± 2.2 MPa). Conclusion: Collectively, our findings support the conclu- sion that multiwalled carbon nanotube/nylon-6 electrospun
Transcript of Color stability of infiltrant resin exposed to different staining solutions
e34 d e n t a l m a t e r i a l s 2 9 S ( 2 0 1 3 ) e1–e96
(n = 10). The control group remained untreated, while theexperimental groups were tested for 3 HP concentrations
(10%, 35% and 50%). The solutions were applied, respec-tively, every 30 min to the enamel, and they were analyzedafter each application. The MC of the enamel was deter-mined before and after the bleaching using Fourier transform(FT-Raman) spectroscopy and micro energy-dispersive X-rayfluorescence spectrometry (�EDXRF). The calcium (Ca) lostfrom the bleached enamel was quantified with an atomicabsorption spectrometer (AAS). The data were statisticallyanalyzed by the ANOVA, Tukey and Dunnett’s test (p = 0.05).
Results: The FT-Raman showed a decrease in MC for allbleaching treatments, without influence of the three differentconcentrations of HP or the number of applications. �EDXRFdid not detect any changes in MC.
Conclusion: Ca loss was observed by the AAS, with no dif-ference among the 3 HP concentrations. The FT-Raman andAAS analysis detected reduction of MC and Ca loss after HPbleaching.
http://dx.doi.org/10.1016/j.dental.2013.08.071
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Color stability of infiltrant resin exposed todifferent staining solutions
A.B. Borges ∗, T.M.F. Caneppele, M.A. Luz, C.R.Pucci, C.R.G. Torres
University Estadual Paulista – UNESP, Brazil
Purpose: The aim of this study was to investigate the stain-ing behavior of the demineralized enamel infiltrated by lowviscosity resin.
Methods and materials: Bovine enamel cylindrical sam-ples (3 mm × 2 mm) were assigned into four groups (n = 45)according to the treatment: sound enamel (control), white spotlesion (WSL) + artificial saliva, WSL + daily application of 0.05%NaF, WSL + resin infiltration (Icon®, DMG). Artificial WSL wereproduced in groups with demineralization. After treatments,color was assessed by spectrophotometry, using CIE L*a*b* sys-tem. The specimens (n = 15) were then immersed in deionizedwater, red wine or coffee for 10 min daily during 8 days. Colorwas measured again and the specimens were repolished withsandpaper discs. The final color was assessed. Data were ana-lyzed by two-way ANOVA and Tukey tests (a = 0.05). Pairedt-test was used for comparison between staining and repol-ishing conditions.
Results: The results are presented in the table.Conclusion: The exposure of specimens to colored solu-
tions resulted in significant color alteration. The white spotlesions treated with resin infiltration showed significantly
higher staining than all other tested groups, however, repol-ishing of the specimens minimized the staining effect.
Groups Sound enamel White spot lesion + AS White spot lesion + DF White spot lesion + RI
�Ea �E2b �E1a �E2b �E1a �E2b �E1a �E2b
Water 2.4 (1.3)a 2.2 (0.9)AB 2.9 (1.6)a 2.0 (1.3)AB 2.7 (2.2)a 1.6 (1.8)A 2.3 (1.7)a 2.1 (0.9)ABWine 14.4 (4.2)c cd 10.1 (2.2)c C 11.1 (5.1)c bc 9.3 (5.4)c C 14.2 (2.7)c cd 8.4 (3.2)c C 17.3 (2.7)c de 14.7 (4.7)c DCoffee 14.5 (4.4)cd 8.1 (4.5)c C 9.5 (5.9)c b 8.4 (5.7)c C 7.3 (2.3)c b 6.0 (1.4)c BC 21.3 (4.3)c e 16.6 (4.3)c D
a Different lower case letters mean significant differences among thegroups for �E1 (p < 0.05).
b Different capital letters mean significant differences among thegroups for �E2 (p < 0.05).
c Significant difference between �E1 and �E2 for each substrate con-dition, using paired t-test (p < 0.05).
http://dx.doi.org/10.1016/j.dental.2013.08.072
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Multiwalled carbon nanotube/nylon-6nanofiber-reinforced dental composite
A.L.S. Borges 1,∗, A.C. Souza 1, T.J.A. PaesJunior 1, T. Yoshida 2, M.C. Bottino 2
1 University Est. Paulista – UNESP, Sao Jose DosCampos, Brazil2 Indiana University, IN, USA
Purpose: The aims of this study were (1) to synthe-size/characterize both random and aligned multiwalledcarbon nanotubes/nylon-6 (MWCNT/N6) nanofibers and (2) todetermine the effect of nanofiber incorporation on the flexuralstrength (FS) of a dental composite (C).
Methods and materials: MWCNT were functionalized(MWCNT) using 12N HCl for 5 min, washed in DI waterand dried for 24 h at RT. N6 was dissolved at 10% inhexafluoro-2-propanol. Then, two distinct MWCNT concen-trations (0.5 and 1.5 wt.%) were added to the N6 solution,stirred overnight and sonicated before use. N6 nanofibersboth non-aligned/NA and aligned/A with and without MWCNTwere processed via electrospinning, as follows: G1-N6/NA, G2-N6/A, G3-N6/NA + 0.5%MWCNT, G4-N6/NA + 1.5%MWCNT, G5-N6/A + 0.5%MWCNT and G6-N6/A + 1.5%MWCNT. Morpholog-ical (SEM/TEM), chemical, and mechanical (tensile strength,TS), studies were carried out after vacuum drying nanofibersat RT for 2 days. Nanofiber sheets (2 mm × 2 mm × 20 mm),of all groups, were cut and used to prepare the composite(GrandioSO®-VOCO) specimens (n = 6) for flexural testing. Datawere analyzed by ANOVA 2-way and Tukey’s test (5%).
Results: G2(18.4 ± 2.3 MPa) and G5(19.7 ± 2.5 MPa) showedsignificantly higher tensile strength than G1(5.8 ± 1.8 MPa)regardless the MWCNT content (Table). The incorporation ofthe synthesized nanocomposites fibers enhanced significantlythe composite flexural strength (Table) when compared to thecontrol (without MWCNT) with better results associated withaligned N6 + 0.5% MWCNT nanofibers (G5 = 142.3 ± 2.2 MPa).
Conclusion: Collectively, our findings support the conclu-sion that multiwalled carbon nanotube/nylon-6 electrospun
