Mineral trioxide aggregateFrom Wikipedia, the free encyclopedia

Mineral Trioxide Aggregate (MTA) is a dental material used in vital pulp therapy and some endodontic [root

canal] procedures. Mineral Trioxide Aggregate (MTA) was named in 1998 by Dentsply Tulsa Dental (ProRoot

MTA, Dentsply Tulsa Dental, Johnson City, TN, USA) as developed by Dr. Torabinejad. MTA was originally

developed for perforation repair and root end filling. MTA was a refined (reagented) Portland Cement Type I

with Bismuth Trioxide for radiopcity. MTA has expanded its uses to one-visit apexification, pulp capping and

root canal obturation and so on. MTA is expanding the meaning from Portland Cement to all kinds of Mineral

Aggregate including Limestone cement, Calcium Aluminate Cement, Magnesium Silicate Cement, Lithium

Silicate Cement as natural ceramic cements widely. MTA is the name of speific product material, which is

Dental Material of mineal aggregate and radiopacifier of Bismuth Trioxide.

Contents

  [hide] 

1 Composition

2 Characteristics & Products

3 Usage in some clinical cases

o 3.1 Root-end Filling after Apicoectomy

o 3.2 Internal & External Root Resorption & Obturation

o 3.3 Lateral or furcation perforation

o 3.4 Root Canal Sealer

o 3.5 Pulp capping

4 See also

5 References

6 External links

Composition[edit]

MTA is composed of 1. tricalcium silicate, 2. dicalcium silicate, 3. tricalcium aluminate, 4. tetracalcium

aluminoferrite, 5. calcium sulfate and 6. bismuth oxide. The later 4 phases vary among the commercial

products available. Original ProRoot MTA is a refined Portland Cement with Bismuth Trioxide as radiopacifying

agent. ProRoot MTA is especially made by Portland Cement Type I, 55% (C3S), 19% (C2S), 10% (C3A), 7%

(C4AF), 2.8% MgO, 2.9% (SO3), 1.0% Ignition loss, and 1.0% free CaO. A limitation on the composition is that

the (C3A) shall not exceed fifteen percent. Main constituents of MTA are tricalcium silicate and dicalcium

silicate naturally composed. MTA contains innated tricalcium aluminate (C3A)and tetracalcium

aluminoferrite(C4AF). These constituents are determined to Portland Cement Type (I to V). White MTA was

developed for reducing of discoloration to tooth structure. It was eliminating C4AF (tetracalcium aluminoferrite)

as iron (Fe)'s main discoloration induced element. The initial White MTA contained significantly lesser amount

of aluminum oxide (Al2O3), magnesium oixde (MgO) and ferric oxide (Fe2O3) than grey MTA. The current

White MTA was developed by Dr. Carolyn Primus in 2008 with White Portland Cement. - White Portland

Cement - Limestone Silica Compounding Cement, main consitituent isCalcium Carbonate Cement

of Limestone.

Rawmix formulation

"The characteristic greenish-gray to brown color of ordinary Portland cement derives from a number of

transitional elements in its chemical composition. These are, in descending order of coloring effect, chromium,

manganese, iron, copper, vanadium, nickel and titanium. The amount of these in white cement is

minimized as far as possible. Cr2O3 is kept below 0.003%, Mn2O3 is kept below 0.03%, and Fe2O3 is kept

below 0.35% in the clinker. The other elements are usually not a significant problem. Portland cement is usually

made from cheap, quarried raw materials, and these usually contain substantial amounts of Cr, Mn and Fe. For

example, limestones used in cement manufacture usually contain 0.3-1% Fe2O3, whereas levels below

0.1% are sought in limestones for white manufacture. Typical clays used in gray cement rawmix may contain 5-

15% Fe2O3. Levels below 0.5% are desirable, and conventional clays are usually replaced with kaolin. Kaolin

is fairly low in SiO2, and so a large amount of sand is usually also included in the mix. Iron and manganese

usually occur together in nature, so that selection of low-iron materials usually ensures that manganese content

is also low, but chromium can arise from other sources, notably from the wear of chrome steel grinding

equipment during the production of rawmix. See rawmill. This wear is exacerbated by the high sand-content of

the mix, which makes it extremely abrasive. Furthermore, to make a combinable rawmix, the sand must be

ground to below 45 μm particle diameter. Often this is achieved by grinding the sand separately, using ceramic

grinding media to reduce contamination."

Also newly developed fast set MTAs were developed by Pozzolan Cement or Zeolite Cement. These were

used by pozzolanic reaction. Pozzolan Cement is a mineral aggregate with waterycalcium silicate hydration.

Components (phases) in MTA

Tricalcium silicate (CaO)3.SiO2

Dicalcium silicate (CaO)2.SiO2

Tricalcium aluminate (CaO)3.Al2O3

Tetracalcium aluminoferrite (CaO)4.Al2O3.Fe2O3

Gypsum CaSO4 · 2 H2O

Bismuth oxide Bi2O3

MTA was developed by the research pioneer and Endodontist, Dr. Mahmoud Torabinejad at Loma Linda

University, and his patient Dean White (US Patents 5,769,638 and 5,415,547). White MTA was developed by

Dr. Carolyn Primus (US Patent 7,892,342). It was made from White Portland Cement (Limestone - Calcium

Carbonate - Silica compounding Cement).

Originally, MTA was formulated from commercial Portland cement combined with bismuth oxide powder for

radiopacity , to make the material visible on a dental x-ray. However, dental materials are required to have high

purity and be lead and arsenic-free, unlike portland cement, and dental companies have created materials to

meet the dental standards (ISO 9917) for purity and performance (ISO 6876 and ADA 57). The original MTA

was dark gray in color, but white versions have been on the market since 2002. ProRoot® MTA and MTA

Angelus® brands are based on the original formulas for white and gray MTA, contain roughly 20% bismuth

oxide, and are available as white or gray. Source: [1] Current tooth-colored MTA was marketed in 2008 by US

Patent 7,892,342. Original MTA was formulated form Ordinary Portland Cement as Calcium Silicates, but

current White MTA was developed by White Ordinary Portland Cement as different manufacturing process and

different raw material of Calcium Carbonate (Limestone). Though chemical compositions are similar, the

properties and activities are different by the raw materials' compounding technology. Oridnary Portland

Cement is made by long-term natural process of heat and compression. But limestone silica compounding

cement is artificially compounded by decarbonation and mixturing process of Lime (CaO) and Silica (SiO2) with

Alumina (Al2O3).

Aluminum-containing phases, and calcium sulfate are minor phases present in some MTA products. Although

some studies have shown an increased risk of developing Alzheimer's disease withenvironmental factors such

the intake of metals, particularly aluminium, ; the neurotoxicity of calcium aluminate compounds has not been

demonstrated. [1]

[2] [3] [4] a search on neurotoxicity of aluminum of the PubMed database listed 328 individual articles, as of 8

Feb 2013.

Characteristics & Products[edit]

1.Biocompatible with periradicular tissues 2.Non cytotoxic to cells, but antimicrobial to bacteria 3.Non-

resorbable 4.Minimal leakage around the margins. 5.Very basic AKA alkaline (high pH when mixed with water).

6. As a root-end filling material MTA shows less leakage than other root-end filling materials, which means

bacterial migration to the apex is diminished. 7. Treated area needs to be infection free when applying MTA,

because an acidic environment will prevent MTA from setting. 8. Compressive strength develops over a period

of 28 days, similar to Portland cement. Strengths of more than 50 MPa are achieved when mixed in a powder-

to-liquid ratio of more than 3 to 1.[citation needed]

Originally, MTA products required a few hours for the initial and final setting, which is uncommon in dental

materials. The first patented products were either gray or white ProRoot MTA from

Dentsply. http://www.tulsadentalspecialties.com/default/endodontics/Ultrasonics/rootrepair.aspx Newer

materials are available that set more quickly and have added characteristics. For instance, Angelus company

has made MTA products similar to ProRoot MTA, but added a salicylate based sealer, have less than 20%

MTA powder.

MTA Plus® is washout resistant.[5] MTA Plus is available from www.avalonbiomed.com and may be used for 10

indications.

MTA Products: Original ProRoot MTA Grey: Calcium Alumino-Silicate Cement (C3S, C2S with C3A)- Portland

Cement Type I with Bismuth Trioxide. (ex. MTA Angelus Grey) ProRoot MTA White : Calcium Carbonate

alumino-silicate Cement (CaCO3 + SiO2 with Al2O3). Final phase is similare to Portland Cement. (Limestone

Portland Cement) -ex. MTA Angelus Blanc, EndoCem/Zr, MM MTA, Tech BioSeal MTA, Trioxident, most white

MTAs.

Setting Time: Original ProRoot MTA is set by water. But for faster/quicker setting, there are hydration

accelerants. Also Alumina more containing MTA can be set faster than less alumina containing MTA. GIC

Solultion is Polyacrylic acid. GIC is alumino-SILICATE (Glass) bioceramic cement. As MTA is mainly composed

of calcium-alumino-silicate, PAA (Polyacrylic acid) is an accelerant for MTA. PAA set MTA within 15–18

minutes. More aluminate, faster set. Also high concentrated Calcium Chloride (CaCl2, 70% more) is well known

as accelerator of Portland Cement. So high concentrated -over 70%- Calcium Chloride solution sets MTA

within 12 minutes. Or Pozzolanic reaction is also faster set chemical reation of calcium silicate hydrate. By this

pozzolanic reaction, MTA Agelus, MM MTA and EndoCem MTA are pozzolan -calcium carbonate with fumed

silica- hydration for fast set. But pozzolanic reacted cement has lower compressive strength at 15 MPa

maximum. Easy broken and easily removable property of Pozzolanic MTA.

Alternative to MTAs - BioA, Bioceramic Aggregate

Mineral is ceramic in nature. MTA was used by mineral aggregates from natural resources. Instead of mineral

aggregate, sythetic artificial pure calcium silicate is used for dental and medical products. It is named

as Bioceramic (chemically bonded cermic) cement. Recently medical graded Calcium Silicate Based Materials

were developed. It is the replacement of MTA. So it is classified as Bio-Aggregates, BA or BioA. Hydraulic

Calcium Silicate Cements are integrated name of Calcium Silicate Based Materials. The examples are

BioDentine and BioAggregate (DiaRoot). Silicate based bioceramic is a glass ionomer cement (GIC) as

restorative material. Calcium based bioceramics are Calcium Phosphate, Calcium Carbonate, Calcium

Aluminate, Calcium Sulfate and Calcium Silicate, etc. However, as Calcium Phosphate, Calcium Sulfate and

Calcium Carbonate are biodegradable materials, these are used for bone grafting material. As root canal filling

material and root repair material is non-biodegradable material permanently, so Calcium Aluminate Cement

and Calcium Silicate Bioceramic materials have been used for endodontic materials and restorative materials.

Calcium Alumino-Silicate cement is a potential material. In Root canal sealing/filling material, Calcium Based

Material with bioactivity is commonly used rather than Alumina-based material of Calcium Aluminate Cement

because alumina is bioinert bioceramic.

BioAggregate was marketed after FDA approval in 2006, 2 years faster than White Portland Cement MTA by

Dr. Carolyn Primus in 2008. BioAggregate is newly pure medical graded Calcium Silicates (tricalcium silicate

and dicalcium silicate) by 65% and Calcium Phosphate as admixture by 6% and Tantalum Pentoxide by 25%

as radiopcifier. This is the artificial name of Bioceramic Aggregate in opposition of Mineral Aggregate. Mineral

is Ceramic in Nature, Bioceramic is Chemically Bonded Ceramic, Artificial sythetic pure Calcium Silicates. So

there is no toxic heavy metals and unnecessary heavy metals of iron, manganese, nickel, copper, zinc. Also

BioA is not used by bismuth Trioxide, but by Tantalum Pentoxide, Zirconia, or Calcium Tungstate as

radiopaque material. It is a differentiation from MTA, Trioxide. Before MTA was developed, Calcium Phosphate

Bioceramic materials were developed as root-end filling material. But Calcium Silicate Bioceramic materials

have been used only as bone cement or admixture. After MTA is nothing but Portland Cement (Calcium-

Alumino-Silicate Cement), pure calcium silicate bioceramic materials were developed for root-end and root

canal filling material. After researching, BioAggregate (DiaRoot) was approved by FDA and then marketed. It's

an alternative to Mineral Trioxide Aggregate.

Biodentine material is a newer tri/dicalcium silicate powder (aluminum-free) that is made radiopaque with

zirconia, and has salt and other additives for quicker

setting.http://www.septodontusa.com/products/biodentine Biodentine is pure tricalcium silicate and dicalcium

silicate with calcium carbonate by 20% and high concentrated calcium chloride solution as hydration

accelerant. It is called as tricalcium biosilicate technology. Biodentine is also an alternative to MTA. - aluminum-

free (non-tricalcium aluminate) and zirconia (ZrO2) instead of Bismuth Trioxide.

Brasseler offers paste and putty versions of tri/dicalcium silicate, including sealer, which set in

vivo. http://shop.brasselerusa.com/storefrontB2CWEB/itemdetail.do?action=prepare_detail&itm_id=58731 The

Brasseler products are based on the same free-tricalcium aluminate containing powders as Diaroot

BioAggregate, Bioceramic Aggregate. These powders are very white, non-discoloration and are made

radiopaque by tantalum pentoxide and zirconia or any other radiopacifying agents except Bismuth Trioxide.

Brasseler's Bioceramic sealers (BC Sealer, RRM and RRM Putty) are different from powderic bioceramic

materials. The compositions are similar to bio-Aggregate, but the material is in paste-form of bioceramic gel

formation. BioAggregate is an alternative to MTA. Bioceramic pastes are higher technologies of Bio Tech,

Ceramic Tech and Nano Tech integrated technology based advanced bioMaterial (esp. Bioceramic Science)

for dental and medical purpose.

These hydraulic Calcium Silicate based materials are alternatives to Mineral calcium silicate cements. Alumino-

silicate bioceramic, Calcium Aluminate Bioceramic, Calcium Alumino-Silicate Bioceramics are developed for

Root-end filling and root canal filling materials rather than mineral aggregate based materials.

Usage in some clinical cases[edit]

Root-end Filling after Apicoectomy[edit]

In root canal therapy where an apical infection is persistent, an apicoectomy may be required. Flap is raised

over the tooth and the root tip is resected and a cavity created (3–4 mm) in the root tip removed. Retrograde

application of MTA to the root tip cavity is completed.

MTA was originally developed for Root-end Filling. There were several different materials such as amalgam,

reinforced zinc oxide eugenol cements (intrim restorative material - IRM, Super ethoxy Benzonic acid

[EBA], glass ionomer cement and composite resin for Root-end Filling after Apicoectomy. MTA, a refined

"Portland Cement" - Calcium Alumino-Silicate Cement-, was found to have less cytotoxic and better results in

biocompatibility and micro-leakage sealing ability, giving it more success over root-end filling materials. But

MTA is not acceptable as "ideal root-end filling material" because MTA has some drawbacks of toxic heavy

metal presence, discoloration, difficult handling, short working time, long setting time, washout before setting

and washout after set (Calcium carbonate based MTA has solvent of carbonic acid).

For ideal Root-end filling, there are many new materials or improved materials developed. 1. Glass Ionomer

Cement: It's based on Alumino-Silicate Based Bioceramic material. Most cytotoxicity is caused by Polyacrylic

acid. So current GIC as root-end filling material is reducing the cytotoxic acclerator's concentration. - Calcium

Alumino-Silicate - MTA (CALCIUM alumino-Silicate) + GIC (alumino-SILICATE), Calcium reinforced glass

ionomer cement is developed. It's a promising material.

2. Calcium Phosphate Cement (Hydroxyapatite) Bioceramic Material: CPC has been studied since Dr.

Laurence Chow in 1985 in USA. Bone Grafting Material, artificial Bioceramic CPC is developed for Root-end

filling or pilot material in Root-end filling and root repair material.

3. Calcium Silicate Based Material - Bioceramic material: It was known as Bioceramic Sealers. But actual

Bioceramic Aggregates are composed of pure medical graded Calcium Silicate Based material. BioAggregate,

Biodentine, EndoSequence RRM and RRM Putty are based on Calcium Silicate Bioceramic material.

4. Calcium Aluminate Bioceramic material - (alumina cement in minerals, calcium aluminate cements in

bioceramics) Alumina is an initial fast setting element and high compressive strength. It has been used as

dental products as luting agent. Calcium Aluminate Cement (bioceramic) has been developed for dental

products and root-end filling material. Ceramir by Doxa Dental in Sweden.

These newly developed root-end filling materials are based on bioceramic, chemically bonded ceramic, not

by mineral (ceramic in nature) like MTA. Even if mineral shows higher biocompatibility, minerals have potential

toxic heavy metals in material. Bioceramic or bioMaterial is used for medical and dental

products. BioMaterials can reduce the issues on discoloration and toxic heavy metals' presence initially.

Internal & External Root Resorption & Obturation[edit]

In internal resorption… root canal therapy is performed, putty mixture of MTA is inserted in the canal using

pluggers to the level of the defect. Gutta percha and root canal sealer are placed above the defect to complete

the root canal treatment. In direct cases, the canal may be completely obturated with MTA. The MTA will

provide structure and strength to the tooth by replacing the resorbed tooth structure. In external resorption…

after root canal therapy is performed. Flap is raised over the tooth and the defect removed from the root

surface with a round bur. Retrograde application of MTA to the root surface is then completed.

Lateral or furcation perforation[edit]

Lateral perforation occurs when an instrument has perforated the root during cleaning & shaping of the canal

by the dentist. If it happens, one should finish cleaning & shaping of the canal , irrigate the canal with sodium

hypochlorite to disinfect it and dry it with a paper point. The perforation can be sealed with a thick mixture of an

MTA-type product, preventing bacterial ingress. Make sure that you can locate the canal while the MTA has not

set and remove the excess material from the area.

Root Canal Sealer[edit]

Several MTA products are available as sealer. MTA Plus™ has the highest percentage of MTA in its formula.

(www.avalonbiomed.com) As Calcium based materials have washout property in dam, the antiwashout agents

are used. The examples are chitosan and gelatin, which has been used with injectable bone grafting paste.

MTA Plus is used with gelatin complex as antiwashout agent. MTA Angelus Fillapex® sealer contains less than

20% tri/dicalcium silicate powder in a salicylate carrier medium. By element analysis, there is no bismuth oxide

of MTA. Instead, MTA Fillapex is composed of Calcium Oxide and Silica in salicylate resin like Sealapex.

EndoSeal MTA, Tech BioSeal MTA are also MTA Root Canal Sealer. MTA is used as filler in the resin like MTA

Fillapex. In epoxy resin based sealer, MTA is mixed with fillers. But it is not MTA Based Root Canal Sealer, but

Resin Modified Root Canal Sealer.

Newly non-MTA (Bioceramic, BioA) Root Canal Sealers: BioAggregate, BC Sealer, RRM, Biobinder, calcium

aluminate bioceramic root canal sealer, calcium phosphate injectable Root canal sealers were developed and

are devloped for root canal sealer. They are not a kind of MTA Sealer, but a BioA or Bioceramic based Sealer.

Brasseler Endosequence® offers a pre-mixed sealer with a non-reactive carrier medium and the product only

sets in vivo. Brasseler's EndoSequence Bioceramic sealers are not MTA, but Calcium Silicate Based material.

Its medium is used with inorganic bioceramic gel type (non-biodegradable), which is different from organic

agents of chitosan or gelatin (biodegradable). By bioceramic high technology, it is set by the water/moisture in

the root canal and body. 100% hydraulic bioceramic without mixing of hardener before using. Root Canal

Sealer is required by non-discoloration and non-toxic heavy metals and easy handling and higher

biocompatibility, bioactivity and bacteria-tight sealing. These ideal requirements need more bioMaterial than

minerals.

Apexification (Necrotic pulp)

When the root is not completely formed in adolescents, but an infection occurs nd the pulp is not vital,

apexification can be performed to maintain the tooth in position as the roots develop. In case of non-vital pulp:

1. Isolate the tooth with a rubber dam 2. perform root canal treatment. 3. Mix the MTA and insert it to the apex

of the tooth, creating a 3 mm thickness of plug. 5. Fill the canal with sealer and gutta percha.

Apexogenesis (Vital pulp)

The process of maintaining pulp vitality during pulpal treatment to allow continued development of the entire

root (apical closure occurs approximately 3 years after eruption). 1. Isolate the tooth with a rubber dam 2.

Perform a pulpotomy procedure. 3. Place the MTA material over the pulp and close the tooth with temporary

cement until the apex is completely formed.

Pulp capping[edit]

In case of mechanical exposure that occurs during cavity preparation and not a pathological exposure due

to caries. Proper isolation should be completed using a rubber dam and cotton pellet.Disinfection of the cavity

with sodium hypochlorite. then application of MTA over the exposure area. restoration of the cavity

with amalgam or composite is done. MTA provides a higher incidence and faster rate of

reparative dentin formation without the pulpal inflammation.

MTA Plus material is also indicated for base and liner in vital pulp therapy. In root-end filling after apicoetomy,

the anti-washout agent (chitosan or gelatin) is useful to prevent from MTA washout. But in vital pulp therapy,

anti-washout gel doesn't increase bioactivity or bacterial tight sealing ability of MTA. Instead, hydraulic (100%

pure water) MTA shows the higher success rate than anti-washout gel or resin medium. Resin Modified MTA or

Calcium Silicate Cement was marketed already. TheraCal LC is HEMA-Free Resin Modified Calcium Silicate

Cement (MTA-like, Portland Cement Type III) Light-curable for base and liner in vital pulp therapy