Clinical Usage of Mineral Trioxide Aggregate for Veterinary Dentists
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Discusses the science of MTA. How to use MTA. Differences in MTA brands. And how to make your own MTA for research purposes. There are some Chuck Norris jokes in there too.
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Clinical Usage of Mineral Trioxide Aggregate for Veterinary Dentists
- 1. The properties of MTA and how it can be manipulated William Ha Part 1. MTA Chemistry and Brands
- 4. Calcium hydroxide & MTA
- 5. Ideal Properties Ca(OH)2 paste Brands Calcipulp, Pulpdent, Calyxl Key / Majority Reactants: As below Key / Majority Products: Ca+ (aq) + 2OH- (aq) + Gel- like thickening agent (eg Methylcellulose) State & Handling Paste Immediate pH: 12.5 Antibacterial effect Strong Long term state: Soluble Promotes healing ✔✔✔ Seals the tooth ✖✖✖ Clinical indication Therapeutic dressing
- 6. Ideal Properties Ca(OH)2 paste Ca(OH)2 cement Brands Calcipulp, Pulpdent, Calyxl Dycal, MTA Fillapex, Life Key / Majority Reactants: As below Butylene glycol disalicylate(l) + Ca(OH)2(s) Key / Majority Products: Ca+ (aq) + 2OH- (aq) + Gel- like thickening agent (eg Methylcellulose) Calcium disalicylate(S) + 2H2O(l) State & Handling Paste Thick Paste that solidifies into flaky cement Immediate pH: 12.5 9-10 Antibacterial effect Strong Mild Long term state: Soluble Semi Soluble Promotes healing ✔✔✔ ✔ Seals the tooth ✖✖✖ ✖ Clinical indication Therapeutic dressing Liner
- 7. Ideal Properties Ca(OH)2 paste Ca(OH)2 cement MTA Brands Calcipulp, Pulpdent, Calyxl Dycal, MTAFillapex, Life ProRoot MTA, MTA Angelus Key / Majority Reactants: As below Butylene glycol disalicylate(l) + Ca(OH)2(s) 2(CaO)3(SiO2) (s) + 2(CaO)2(SiO2) (s) +12H2O(l) Key / Majority Products: Ca+ (aq) + 2OH- (aq) + Gel- like thickening agent (eg Methylcellulose) Calcium disalicylate(S) + 2H2O(l) 2[(CaO)3(SiO2)2•4H2O] (s) + 4Ca+ (aq) + 8OH- (aq) State & Handling Paste Thick Paste that solidifies into flaky cement Hard Paste that solidifies into rock like cement Immediate pH: 12.5 9-10 12.5 Antibacterial effect Strong Mild Strong Long term state: Soluble Semi Soluble Insoluble Promotes healing ✔✔✔ ✔ ✔✔✔ Seals the tooth ✖✖✖ ✖ ✔✔✔ Clinical indication Therapeutic dressing Liner Permanent restoration
- 8. What is MTA?
- 9. 80% Portland Cement Therapeutic component 20% Bismuth Oxide Radiopaque agent Quality Assurance Cement fit for human use
- 10. What is Portland cement?
- 12. What is Bismuth Oxide?
- 13. Materials Radiopacity (in mm Al) Enamel 1.8mm Dentine 0.79-1.13mm Portland Cement 0.96mm MTA 6.53-6.62mm
- 14. Before Treatment Treatment with MTA (+) Diagnostic Placement Treatment with Portland Cement (-) Difficult to determine adequacy of restoration ✔✗
- 15. Chemical Reactions in the setting of MTA
- 16. Reactants Products Portland Cement Calcium Silicates Calcium Aluminates Calcium-silicate-hydrate Calcium-aluminate-hydrate +Water +Calcium hydroxide +Water Unreacted Bismuth Oxide Unreacted Bismuth Oxide
- 17. Calcium Hydroxide and pH
- 23. MTA Pulp Capping
- 24. MTA Pulpotomy
- 25. Staining & MTA
- 28. MTA Apexification / Apical Stop
- 29. MTA Apicoectomy
- 30. Success Rates
- 32. Pulp capping in Permanent Teeth: 97.6%
- 33. Pulpotomy in Permanent Teeth: 79%
- 35. Apical Barrier: 76-81% *Witherspoon 2008 Apical Barriers: 90%
- 36. Differences between MTA variants
- 37. The original MTA and with the most supporting evidence – 5grams (10 sachets) $800 – Or 2 grams (4 sachets) $350 If you use 1 use per 0.5 gram: • $80 per use (from 5 gram pack) & $85 per use (from 2 gram pack) If you are going to use the left-over amounts per satchel: • Assuming 7 uses per 1 gram. • $22 per use (from 5 gram pack) & $25 per use (from 2 gram pack) Advertised setting time: 4 hours
- 38. Copycat product. Sets slightly faster as it has no gypsum (a setting controller in ProRoot). Ie 95% chemically similar to ProRoot A lot of evidence to show the clinical outcomes are similar to ProRoot Advertised that 1gram is good for 7 applications • Re-sealable jar 1gram jars for $100.79 • $14.40 per use
- 39. ProRoot MTA Biodentine 75% Calcium Silicates and aluminates 85% calcium silicates 5% Gypsum 10% Calcium Carbonate 20% Bismuth Oxide 5% Zirconium Oxide 100% distilled water Water with 15% Calcium chloride and polycarboxylate
- 40. ProRoot MTA Biodentine 75% Calcium Silicates and aluminates 85% calcium silicates 5% Gypsum 10% Calcium Carbonate 20% Bismuth Oxide 5% Zirconium Oxide 100% distilled water Water with 15% Calcium chloride and polycarboxylate ProRoot is less soluble
- 41. ProRoot MTA Biodentine 75% Calcium Silicates and aluminates 85% calcium silicates 5% Gypsum 10% Calcium Carbonate 20% Bismuth Oxide 5% Zirconium Oxide 100% distilled water Water with 15% Calcium chloride and polycarboxylate Biodentine sets faster
- 42. ProRoot MTA Biodentine 75% Calcium Silicates and aluminates 85% calcium silicates 5% Gypsum 10% Calcium Carbonate 20% Bismuth Oxide 5% Zirconium Oxide 100% distilled water Water with 15% Calcium chloride and polycarboxylate ProRoot is more radiopaque. Biodentine FAILS ISO6876 radiopacity requirements
- 43. ProRoot MTA Biodentine 75% Calcium Silicates and aluminates 85% calcium silicates 5% Gypsum 10% Calcium Carbonate 20% Bismuth Oxide 5% Zirconium Oxide 100% distilled water Water with 15% Calcium chloride and polycarboxylate Biodentine sets harder
- 44. How do you mix it Biodentine?
- 45. Box of 15 one-use-only capsules $193.50 from HSHalas • $12.90 per use Much less clinical evidence of success, but looks good as a potential pulp cap material and maybe pulpotomies. No great clinical comparative studies against MTA May be a bad idea for apexification and other endodontic scenarios
- 47. Setting reaction Resin (same as Dycal) + (13%) PC + Water from Dentine Resin + Ca(OH)2 + Setting MTA Structure Set Resin + Set MTA
- 48. “Light Cured MTA” Composition: Portland cement, Polyethylene glycol,dimethacrylate, MEHQ, AeroSil 200, Bis GMA, camphorquinone, barium sulfate, EDMAB. No water in liquid ie Cannot release calcium hydroxide No clinical trials Claims to release more calcium hydroxide however, that’s of a study where they placed the unset resin into water
- 49. Amalgadent: 1gm syringe $36. • 4 syringe pack $99 Erskine dental: • 1 syringe $36.30 • 4 syringe pack $123.50 Approximately $1.21 per use
- 50. Brand Summary ProRoot MTA MTA Angelus Biodentine MTA Fillapex Theracal LC What is it really? PC + Bismuth Oxide PC + Bismuth Oxide Modified PC + ZrO Dycal + PC Flowable resin + PC Clinical Uses Endodontic repair Endodontic repair Endodontic repair Endodontic Sealer Pulp caps only Packaging 1 use only satchels Resealable jar Manually combined, capsule mixed Two part mixing paste syringe Single one component syringe Setting speed* 4 hours 15 Minutes 6 Minutes 2 hours (but needs water from dentine) Light Cured Evidence base Very extensive studies Extensive studies. Chemically almost identical to ProRoot MTA Mostly small trials and case reports. Promising results Performance equal to or less than AH26 (from what I’ve read) Mainly anecdotal and lab studies Cost to buy 5grams (5 satchels) $815.81 Or 2 grams (2 satchels) $341.65 1gram jars for $100.79 15 capsules $193.50 12g for $165 Amalgadent: 1gm syringe $36. 4 syringe pack $99 Cost per use $171 for 1 use only $24 for re-using packet $14.40 per use $12.90 per use 10 automix tips $16.50 per use or cheaper with refill heads $1.21 per use Supplier Dentsply Gunz Halas Gunz Erskine Dental & Amalgadent
- 51. 3 Facts About Chuck Norris, Vet Surgeon • Chuck Norris's tears eliminate all pathogens. But he has never cried. • Chuck Norris doesn't watch out for transmissible diseases. Transmissible watch out for Chuck Norris • Chuck Norris doesn't need radiographs for his diagnosis. He stares the animal down until he gets the information he needs
- 52. Part 2: Handling MTA
- 53. Acid environment with MTA
- 54. Reactants Products Portland Cement Calcium Silicates Calcium Aluminates Calcium-silicate-hydrate Calcium-aluminate-hydrate +Water +Calcium hydroxide +Water Unreacted Bismuth Oxide Unreacted Bismuth Oxide
- 55. Reactants Products Portland Cement Calcium Silicates Calcium Aluminates Calcium-silicate-hydrate Calcium-aluminate-hydrate +Water +Calcium hydroxide +Water Unreacted Bismuth Oxide Unreacted Bismuth Oxide 2 HX + Ca(OH)2 -> CaX2 + 2H2O (CaO)a(SiO2)b•cH2O + dHX -> aCaX2 + bH4SiO4 + eH2O (CaO)a(SiO2)b+ aHX + cH2O → aCaX + bH4SiO4
- 56. Reactants Products Portland Cement Calcium Silicates Calcium Aluminates Calcium-silicate-hydrate Calcium-aluminate-hydrate +Water +Calcium hydroxide +Water Unreacted Bismuth Oxide Unreacted Bismuth Oxide 2 HX + Ca(OH)2 -> CaX2 + 2H2O (CaO)a(SiO2)b•cH2O + dHX -> aCaX2 + bH4SiO4 + eH2O (CaO)a(SiO2)b+ aHX + cH2O → aCaX + bH4SiO4
- 57. Fluid contamination effects on MTA
- 58. Hardness of MTA with water, blood, and serum Compressive strength (MPa) of MTA with water and blood
- 59. Working time
- 61. Mixing Tricks
- 64. Distilled water substitution with MTA
- 65. Accelerators (ie quicken the set) Saline NaOCl has been shown to be an accelerator, but also with reduced final strengths. Retarders (slow down the setting) – may totally inhibit the setting Local anaesthetic solutions Chlorhexidine gluconate
- 66. Placing MTA
- 68. MTA Carriers
- 71. Lee Block / MTA Placement Block
- 74. Inserting MTA down a canal
- 76. Cleaning MTA from the walls
- 78. Curing MTA
- 80. 3 Facts about Chuck Norris, Vet Surgeon • Chuck was bitten by a King Cobra. After three days of pain and agony the snake died. • Chuck’s thesis was on Evolution. His findings were, “evolution is based upon the animals he chooses to live”. No one questioned his findings. • I named my Dog after Chuck but I couldn’t train him. Because no one tells Chuck what to do.
- 81. Part 3: How to make MTA (for research purposes) and store MTA
- 82. APVMA and the “Front Page effect”
- 83. • Sakai VT, Moretti AB, Oliveira TM, et al. Pulpotomy of human primary molars with MTA and Portland cement: a randomised controlled trial. British Dental Journal 2009;207 • Conclusions PC may serve as an effective and less expensive MTA substitute in primary molar pulpotomies. Further studies and longer follow-up assessments are needed. • Silva Neto JD, Schnaider TB, Gragnani A, et al. Portland cement with additives in the repair of furcation perforations in dogs. Acta Cirúrgica Brasileira 2012;27:809-814. • Biomineralization occurred for all obturation materials tested, suggesting that these materials have similar biocompatibility.
- 84. How to make MTA
- 85. Portland Cement Radiopaquer 80% PC 20% Bi2O3 70% PC 30% ZrO2 70% PC 30% ZnO 70% PC 30% BaSO4 90% PC 10% Au 90% PC 10%Ag-Sn alloy
- 86. Storing MTA
- 88. Temperature Effects on Storage
- 90. For more on handling http://www.jcda.ca/article/f4 (The article is in the references) http://www.mineraltrioxideaggregate.com/ If you want a copy of my presentation – email me : w.ha@uq.edu.au
- 91. 1. Nerwich A, Figdor D, Messer HH. pH changes in root dentin over a 4-week period following root canal dressing with calcium hydroxide. Journal of Endodontics 1993;19:302-306. 2. Angelus. MTA Fillapex - Endodontic Sealer - Scientific Profile. URL: 'https://www.clinicalresearchdental.com/marketing/mta fillapex - scientific profile_medium.pdf'. Accessed 16 April 2013. 3. Lombardi T, Di Felice R, Muhlhauser J. Analysis of pH variation of various calcium hydroxide compounds in vitro. Bull Group Int Rech Sci Stomatol et Odontol 1991;34:73-78. 4. Torabinejad M, Hong CU, McDonald F, Pitt Ford TR. Physical and chemical properties of a new root-end filling material. Journal of Endodontics 1995;21:349-353. 5. Hwang YC, Lee SH, Hwang IN, et al. Chemical composition, radiopacity, and biocompatibility of Portland cement with bismuth oxide. Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology, and Endodontology 2009;107:e96-102. 6. Heward S, Sedgley CM. Effects of intracanal mineral trioxide aggregate and calcium hydroxide during four weeks on pH changes in simulated root surface resorption defects: an in vitro study using matched pairs of human teeth. Journal of Endodontics 2011;37:40-44. 7. Srinivasan V, Waterhouse P, Whitworth J. Mineral trioxide aggregate in paediatric dentistry. International Journal of Paediatric Dentistry 2009;19:34-47. 8. Witherspoon DE, Small JC, Regan JD, Nunn M. Retrospective analysis of open apex teeth obturated with mineral trioxide aggregate. Journal of Endodontics 2008;34:1171-1176. 9. Accorinte Mde L, Holland R, Reis A, et al. Evaluation of mineral trioxide aggregate and calcium hydroxide cement as pulp-capping agents in human teeth. Journal of Endodontics 2008;34:1-6. 10. Barrieshi-Nusair KM, Qudeimat MA. A prospective clinical study of mineral trioxide aggregate for partial pulpotomy in cariously exposed permanent teeth. Journal of Endodontics 2006;32:731- 735. 11. Simon S, Rilliard F, Berdal A, Machtou P. The use of mineral trioxide aggregate in one-visit apexification treatment: a prospective study. International Endodontic Journal 2007;40:186-197. 12. Ha WN, Bentz DP, Kahler B, Walsh LJ. D90: The strongest contributor to setting time in MTA and Portland cement. Journal of Endodontics 2015; 13. Tsujimoto M, Tsujimoto Y, Ookubo A, et al. Timing for composite resin placement on mineral trioxide aggregate. Journal of Endodontics 2013;39:1167-1170. 14. Faria-Junior NB, Tanomaru-Filho M, Berbert FL, Guerreiro-Tanomaru JM. Antibiofilm activity, pH and solubility of endodontic sealers. International Endodontic Journal 2013; 15. Waltimo TM, Boiesen J, Eriksen HM, Orstavik D. Clinical performance of 3 endodontic sealers. Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology, and Endodontology 2001;92:89-92. 16. Tavares CO, Bottcher DE, Assmann E, et al. Tissue reactions to a new mineral trioxide aggregate-containing endodontic sealer. Journal of Endodontics 2013;39:653-657. 17. Borges RP, Sousa-Neto MD, Versiani MA, et al. Changes in the surface of four calcium silicate-containing endodontic materials and an epoxy resin-based sealer after a solubility test. International Endodontic Journal 2012;45:419-428. 18. Bisco Inc. TheraCal LC - Resin-Modified Calcium Silicate Pulp Protectant / Liner. URL: 'http://www.bisco.com/catalog/ple_bisco_catitemf.asp?iBrand_Id=156&iCat_Id=28'. Accessed 16 April 2013. 19. Gandolfi MG, Siboni F, Prati C. Chemical-physical properties of TheraCal, a novel light-curable MTA-like material for pulp capping. International Endodontic Journal 2012;45:571-579. 20. Hebling J, Lessa FC, Nogueira I, Carvalho RM, Costa CA. Cytotoxicity of resin-based light-cured liners. American Journal of Dentistry 2009;22:137-142. 21. Ha WN, Kahler B, Walsh LJ. Clinical Manipulation of Mineral Trioxide Aggregate: Lessons from the Construction Industry and Their Relevance to Clinical Practice. Journal of the Canadian Dental Association 2015;81:f4. 22. Wang CW, Chiang TY, Chang HC, Ding SJ. Physicochemical properties and osteogenic activity of radiopaque calcium silicate-gelatin cements. Journal of Materials Science: Materials in Medicine 2014;25:2193-2203. 23. Lee ES. A new mineral trioxide aggregate root-end filling technique. Journal of Endodontics 2000;26:764-765. 24. Yeung P, Liewehr FR, Moon PC. A quantitative comparison of the fill density of MTA produced by two placement techniques. Journal of Endodontics 2006;32:456-459. 25. Parashos P, Phoon A, Sathorn C. Effect of ultrasonication on physical properties of mineral trioxide aggregate. Biomed Research International 2014;2014:191984. 26. Sakai VT, Moretti AB, Oliveira TM, et al. Pulpotomy of human primary molars with MTA and Portland cement: a randomised controlled trial. British Dental Journal 2009;207:E5; discussion 128- 129. 27. Silva Neto JD, Schnaider TB, Gragnani A, et al. Portland cement with additives in the repair of furcation perforations in dogs. Acta Cirúrgica Brasileira 2012;27:809-814. 28. Cutajar A, Mallia B, Abela S, Camilleri J. Replacement of radiopacifier in mineral trioxide aggregate; characterization and determination of physical properties. Dental Materials 2011;27:879-891. 29. Camilleri J, Gandolfi MG. Evaluation of the radiopacity of calcium silicate cements containing different radiopacifiers. International Endodontic Journal 2010;43:21-30. 30. Ha WN, Kahler B, Walsh LJ. Particle size changes in unsealed mineral trioxide aggregate powder. Journal of Endodontics 2014;40:423-426.
Editor's Notes
- When I was an undergraduate dental student I was told that MTA was a new product for pulpotomies that was highly successful, but it cost over 100$ per gram. MTA is essentially Portland cement, the material used to build structures like QPAC. This astounded me because Portland cement costs less than $20 for 8kg. I would hope you would agree with me that there is a huge mark up on the cost of MTA. Which begs the following questions … 1/ Why does it cost so much?. 2/ How does it work ? 3/ Is it really a better alternative to other materials , such as calcium hydroxide So these were the questions I asked myself as it led me into my PhD.
- So we have established the fact that MTA is super expensive. So, why are people using it, and what’s wrong with the status quo of Calcium hydroxide?
- As a dental student I was taught a tooth dressed with calcium hydroxide paste, with a pH of 12 inhibits bacterial growth. Calcium hydroxide comes in 2 forms, a paste and a cement. The paste will kill more bacteria, but will leak out of the tooth. The calcium hydroxide cement, is used as a pulp cap as it will set. It might not be as efficacious as the paste in killing bacteria, however, because it sets, it is easier to place a filling on top of it. As a student, I was left wondering, 1/ How can calcium hydroxide be provided as setting solid, as well as a paste? And, 2/ what are the implications of using the paste versus the cement? Another interesting fact was MTA releases calcium hydroxide. SO ….. how is MTA different from calcium hydroxide cement?
- Calcium hydroxide paste is the gold standard for endodontic dressing of canals, however, as it’s a paste, it doesn’t seal the tooth and can be difficult for clinicians to permanently restore the tooth as the paste will smear through the sides when another material is placed above.
- Calcium hydroxide cement, such as dycal, seemed to provide a setting alternative. However, if you look at the chemical reaction, calcium hydroxide is actually consumed in the setting reaction, therefore, the setting pH and antibacterial activity is not as high as calcium hydroxide paste. The set product is flaky with little structural integrity. Angelus has a product called MTA Fillapex which is about 13% MTA with the rest of it basically dycal. You don’t actually mix it with water before placing into the canals therefore I classify MTA Fillapex as calcium hydroxide cement alongside dycal as it’s more like dycal than it is MTA.
- MTA is quite unique because its ingredients, calcium silicate powder, reacts with water to form a wet slurry. This slurry contains calcium hydroxide. The slurry will set hard and seals the tooth well.
- (pause, don’t say anything) for 3 seconds
- MTA is 80% Portland cement, to which bismuth oxide is added to make it radiopaque so it can be seen on radiographs. As it is 80% Portland cement, its properties are almost identical to Portland cement. And, most importantly, its manufacturing processes have been assessed by government bodies who accept that it is a consistent product that has minimized risks to the patient and to you. In Australia, the 2 common brands you will hear about are MTA Angelus, and ProRoot MTA. These 2 brands also have the bulk of evidence based research behind them. The mark up in cost – I believe – is because the manufacturers had to fund research to prove this material works and have to continually answer to regulatory bodies. They also know that the alternatives to MTA are generally inferior and therefore, you almost have no choice to but to use MTA.
- (pause, don’t say anything) – give 3 seconds
- To make Portland cement, stones, are crushed, ground and placed in an oven that reaches temperatures of around 1500 degrees Celsius. The output material is ground further, until it becomes a powder known as Portland cement. This process breaks the bonds that held the stones together so when you add water, the bonds will reform and produce a stone-like cement material.
- (pause, don’t say anything) – give 3 seconds
- A major component of portland cement, bone, and, dental tissues, is calcium. That means the radiopacity of portland cement would be similar to bone and dental tissues. If you restored a tooth with only portland cement, you would not be able to identify your restoration on your radiograph.
- The image on the top is a pre treatment radiograph. The image on the bottom left is a photoshopped image of a tooth that could have been restored with portland cement, while the image on the bottom right is a tooth restored with MTA. If you cannot distinguish your restoration on a radiograph, you can’t be sure you’ve obturated it sufficiently.
- (pause, don’t say anything) – give 3 seconds
- MTA sets with the following chemical reactions. You have cement powder, which are silicates and aluminates which are combined with water, producing a series of hydrated crystalline structures as well as water and calcium hydroxide.. The water and calcium hydroxide sit around the crystal hydrate structures. If you think of a wet sponge as an analogy to set portland cement. The sponge itself is the crystal structures while the pores are full of water and calcium hydroxide.
- (pause, don’t say anything) – give 3 seconds
- When MTA powder is mixed with water, calcium hydroxide is released. This graph compares the pH within teeth with either MTA or calcium hydroxide. Both will result in the tooth becoming alkaline. But, the advantage of MTA over calcium hydroxide pastes is that MTA will also seal the tooth.
- (pause, don’t say anything) – give 3 seconds
- This is a backscatter SEM of set MTA. The white parts are the the bismuth oxide radiopacifier. The black parts are the pores in MTA. The pores are too small for bacterial to fit through, but, even if bacteria could fit through the pores, the pores are full of pH 12 antibacterial calcium hydroxide. Biocompatibility isn’t my area of research. However, I have come up with a dumb-down explanation as to why MTA is more biocompatible than its alternatives.
- Bone and teeth are made of a crystalline hydrated calcium structure known as hydroxypatite . You have other dental filling materials which are metal alloys, resins, eugenol cements, glasses, rubbers which are not biocompatible when implanted into bone. And then you have MTA which is another crystalline hydrated calcium structure. It isn’t bone, but, it’s chemically close enough to bone that bone will grow onto the surface of MTA. The microporosities of bone increases the surface area for blood and hence bone to attach onto the MTA.
- From this advertisement one could be led to believe that MTA could be placed into every part of the tooth. However, you will never be using MTA as a conventional filling material due to its prolonged setting time and it’s final compressive strength is significantly lower than composite and GIC. In endodontics, MTA can be a great material as it can restore defects. So, logically, it SEEMS like a material of choice for obturating canals. However, this is not common practice because 1/ It’s not easy to remove. If you wanted a post space, or wanted to re-treat the tooth, the MTA sets as hard as the neighbouring dentine, and it would be a nightmare to try to drill out. And 2/ It’s also not cheap. So, if you want to save money, just use it where you need it.
- Pulp capping is performed for exposures of the pulp where the pulp itself is vital and not expected to be irreversibly inflamed. Calcium hydroxide has been the gold standard for pulp capping, however, it has problems. Calcium hydroxide is soluble in oral fluids and therefore it can provide an area for bacterial growth once it dissolves. It does not adhere to the tooth and easily dislodges after placement. Instead of calcium hydroxide, MTA can be placed. After placing MTA into the pulpal area, place a layer of resin-modified glass ionomer cement (RMGIC) over MTA to protect it from washing out. Etch the tooth and then wash out the etch. Then place primer and bond adhesive and follow with a composite resin restoration.
- Pulpotomies are performed for deep carious exposures or exposures of the pulp where the pulp is vital and not expected to be irreversibly inflamed. The clinical procedure is otherwise the same as a pulp cap with the key difference being the removal of the pulpal chamber.
- (Pause for 3 seconds)
- MTA can stain teeth. (pause) If you look at this partial pulpotomy, which was performed with white MTA, a darkness has become apparent within this tooth after 17 months. There are two main theories as to why MTA stains. MTA and Portland cement are microporous, with liquids, and ions being able to diffuse through the set cement. If we look back at the SEM, you can image blood products can diffuse through those small pores making MTA black. If you have concrete next to organic matter, the concrete will, over time, absorb the breakdown products and become dark. If you look at where the MTA is at its most stained, the blackness is along the interface of the MTA against the dentine, the area most likely to have blood trying to leak through the MTA. Also, MTA contains bismuth oxide as its radiopaquer, the same radiopaquer found in AH26, a contributor to the staining in teeth that have had endodontic treatment.
- When you place MTA, you have to consider the resultant aesthetics once the material becomes dark over time. If you’re working on a posterior tooth, that may be less of an issue, however, if you’re considering using MTA for pulp capping or pulpotomies in anterior teeth, consider the tooth may soon become discoloured. So, before you place MTA, ask yourself: -1. If the tooth went dark, will it be obvious? -2. Will you be hiding the darkness with thick white restoratives or crowns? -3. Can you place the material further down in the root structure so when darkening of the cement occurs, it will not be noticed.
- The larger the apex the greater the chance that the apical region of the tooth will be inadequately obturated and more difficult for you to length control the obturation material. In the past, multiple appointments to dress the canals with calcium hydroxide were utilized to create a mineral barrier at the apex. With MTA, this procedure can be done in one visit. Teeth with apices wider than a 55 K-file or when apical patency becomes difficult to achieve, you can consider using MTA instead of gutta percha. You place at least 3mm thickness of MTA and then restore the rest with gutta percha, resin, or, more MTA.
- Apical infections that do not respond to conventional and adequate root canal therapy can respond to apicoectomy. This is where the last 3mm of the tooth is removed along with any apical infection. After the last 3mm of the tooth is removed, the end of the root canal is sealed with MTA. MTA is used because it has excellent sealing properties and will encourage healing of the bone around it, unlike the historical alternative of amalgam.
- (pause, don’t say anything)
- (pause again for 3 seconds)
- This table is from a review on MTA’s success rate in various procedures in humans. Simply put, if you use it following the proper protocols, it works. In human teeth, it’s successful as a pulp cap 98% of the time.
- It’s 79% successful in pulpotomies in human adult teeth – for those of you with sharp eyes – I do realise that in the table it says less than 75%, however, that first study listed here by Barreshi had a success rate of 79%.
- In apicoectomies the success rate can be around 80%.. Buuut.
- A more recent study by Witherspoon had a much better success rate of 90%. This is reflective of improved surgical knowledge and techniques.
- (pause for 3 seconds)
- Pro Root MTA was historically one Gram - per satchet - for One Treatment. It now comes in 0.5 gram sachets, halving the cost per use. If you’re going to use ProRoot, it will cost $80 per use if you’re using one sachet per use. If you want to use the sachet for subsequent multiple uses you will have to try and reseal the packets. Use a butterfly clip and then place it in a zip lock bag, or even better, pour the contents into a small jar. Do not use steri pouches as they’re made to leak air and moisture through the paper. Using your ProRoot for multiple uses will make the cost $24 per use, instead of 80, but, it is against the manufacturer’s instructions. The advertised setting time of 4 hours is based on a test to resist indentation by 5MPa. However, you can carefully place other restorative materials above MTA after 10 minutes as the MTA has reached sufficient hardening.
- Another MTA product is MTA Angelus. It’s supplied through Gunz. It’s chemically similar to ProRoot. If you use MTA Angelus, the resealable jar makes the cost $14 per use. The re-sealable jar makes it easier to store for re-use than ProRoot. Its advertised setting time of 15 minutes is based on a test to resist indentation by 0.3MPa. ProRoot’s setting time of resistance to indentation by 5MPa is 4 hours. So it’s frivolous to compare MTA Angelus with ProRoot MTA based on advertised setting time.
- Another product is Biodentine which is marketed as though it’s better than MTA and that it’s apparently a dentine replacement. But, Biodentine doesn’t form dentine, it has many similar components to MTA and thus comparable properties to MTA.
- MTA contains calcium aluminates which are less soluble and more acid resistant. Biodentine does not contain calcium aluminates. Therefore in solubility studies comparing ProRoot and Biodentine, Biodentine comes out worse.
- Gypsum is found in ProRoot MTA which prevents flash setting. Biodentine doesn’t have gypsum, however, it contains the accelerator, calcium carbonate. Although it is generally accepted that a fast setting material is advantageous - this is not always the case in endodontics. In the case of apical barrier placement, where visibility and access can be difficult, a slow setting material gives the user more needed time to gently place the MTA deep within the tooth. In the case of a pulpotomy or pulp capping, where visibility is less of an issue, a faster setting material enables the user to place a permanent restoration quicker within the appointment.
- Both products contain a radiopaque agent. However, Biodentine’s radiopaque agent is less radiopaque and is at lower quantities. Therefore, if you use Biodentine, be prepared to have difficulty identifying if your cavity is properly filled.
- MTA is just mixed with water, while biodentine is provided with a liquid solution with a chemical accelerator as well as a polycarboxylate plasticizer. Therefore, Biodentine sets harder. In the case of Endodontics, I find hardness of little clinical relevance as the material is deep within a root and receives no direct force.
- Before you get excited about the fact it’s capsule mixed, what is actually involved is you open up the capsule, then you apply the liquid droplets into the capsule and then mix this in your mixer. There isn’t a nozzle to inject the material so it’s not like a Fuji9 capsule. You still have to scoop it up like MTA. The advantage is you don’t have to worry about how to mix the material properly. The downside is you can’t just add more powder or liquid should you want to change the handling to your preferred consistency. The 6 minute setting time is handy in cases such as pulpotomy or pulp capping but I would err on the side of caution if you are doing apexification cases and various other endodontic indications as you do not have the freedom of the greater working time. There is also a theory that if you use a capsule mix, that air is incorporated within the mixture resulting in a more porous restoration. A restoration with pores of air is a more soluble restoration.
- You can buy Biodentine from Halas. It’s chemical composition is very similar to MTA so I would not expect its clinical success to be significantly inferior to MTA, however, long term studies are lacking. In cases where you’re after a quick setting time, such as pulpotomies and pulp caps I think it’s a good material.
- This is case from Septodont. It’s being marketed as a filling material that you can restore teeth with, albeit as a temporary filling where you cut back the outer layer and restore it with composite. . It’s funny that their example case shows an open contact case on the radiograph. Either the material easily chips in the patient’s mouth and hence the open contact or the reported 6 minute setting time still isn’t strong enough for the material to hold its shape when you remove the matrix. There’s a few things you will notice. The material looks like MTA. It looks like concrete. The next is its radiopacity is basically the same as dentine or enamel.
- MTA Fillapex is about 13% MTA, however the rest of it is basically dycal – a resin based cement. You don’t actually mix it with water before placing into the canals. The setting reaction of the resin actually consumes calcium hydroxide. So the questions raised would be, (pause) 1/ Will there be any calcium hydroxide left for antibacterial activity? And 2/ Although the setting reaction releases water, will it be enough water to set the MTA?
- You may have heard of Theracal LC. Nicknamed a light cured MTA. It’s actually light cured flowable resin with bits of MTA powder in it. It is advertised as a material for choice for pulp capping. As with flowable resin, there is no mixing water involved in its dispensing and therefore it cannot release calcium hydroxide. If it cannot release calcium hydroxide it cannot kill bacteria and cannot initiate the pulp to heal. Also, there have been no clinical trials on the material to compare its success rate. A study which is often referenced by Theracal LC claims that Theracal LC releases more calcium hydroxide and has a greater pH than alternative products. However, in this study they put unset resin into water and measured the release. It’s very biased as because they used unset resin. If the resin was set the MTA would have been locked into the resin and hence there would have been no calcium hydroxide release.
- You can buy Theracal from amalgadent or erskine dental. For pack of 4 it’s $99. It’s certainly the cheapest per use material, although it’s reportedly only for pulp caps. There are a lot of claims that it is a hydrophilic resin, and it probably is. Therefore, as a composite resin I suspect it’s a very good liner, however, from a pulp therapy point of view I hold reservations on its ability to support repair of the dentine or pulp.
- Here is a summary of the key MTA related products in Australia which is also found in your lecture notes. The prices of these products could now be different and the cost per use was based on rough estimations from the reps. The two products on the right, I personally don’t like to regard as MTA as they’re mostly resin. I personally use ProRoot MTA and MTA Angelus.
- So I’m going to have a mini break to have a glass of water. Rather than wait until the end of the presentation for questions – are there any questions on the first third of the presentation?
- The story I heard, about the invention of MTA was that Mahmoud Torabinejad, the endodontist who invented MTA, was having concrete laid outside of his house for a driveway. While he was at work, it started to rain, and he gave the concreters a call and asked, if the rain would be a problem. The concreters advised it would be fine as the material is water-friendly and shouldn’t affect the overall strength. He had an epiphany, and thought, why not place concrete into teeth? This is an interesting story as, yes, concrete needs water to set. However, excessive water is bad, you can wash away the concrete, a diluted mix has lower strength, and, who wants rain drop marks and little stream lines on their driveway. If the story about how Torabinejad was inspired to create MTA is true, I suspect his concreters were lying to him. Concrete does need water to set, but, if you don’t understand the science, your outcomes won’t be as predictable
- If we go back to the setting reaction of MTA , water reacts with the silicates and aluminates to form hydrate crystals as well as calcium hydroxide.
- You want to avoid acids with MTA If acid is added to setting MTA, it will attack the unreacted powder AND the setting cement. Therefore, if you place MTA in an acidic environment, your MTA may not set, or will be more soluble. In dentistry, there are multiple scenarios where an acidic environment may be present. Teeth that have undergone endodontic disease, such as pulpititis, necrosis, or apical periodontitis will have acids present from the metabolic wastes produced by bacteria as well as acids from the inflammatory response. In the case of a long standing infection, such as apical periodontitis, an interim dressing with calcium hydroxide is worthwhile as it ensures a greater disinfection of the tooth as well as neutralising any acids. Finally, it is important to ensure that acidic irrigants, etchants or conditioners have been adequately washed out prior to MTA placement. The use of sodium hypochlorite to wash the tooth structure is worthwhile as it has a pH of 12 and will neutralize any remaining acid. ----- Meeting Notes (8/07/15 22:58) ----- also if you wish to use etch after placing MTA - place gic/ or bond on top it
- If you wish to use etch after placing MTA as you’re about to place composite resin, you can place a layer of RMGIC or GIC on the MTA and let that set first. Then you can etch the tooth with the GIC instead of exposing your unset MTA to etch.
- (wait 3 seconds)
- The graph on the top left shows the drop in hardness of MTA if the MTA is exposed to blood or serum. The control is normally mixed MTA that isn’t exposed to blood. If the hardness significantly drops, there is a possibility the MTA hasn’t completely set. On the bottom right is a similar study illustrating that, if you have the MTA in contact with blood or serum, the compressive strength drops. Although MTA is marketed as being friendly to setting in wet environments, it is important to minimise the ingress of any tissue fluids while MTA is being placed. So, the ways to minimize bleeding are, where applicable, 1/ use adrenaline in your anaesthetics for vasoconstriction, 2/ manage inflammatory conditions using interim dressings to reduce the amount of pulpal haemorrhage you may have to deal with, and, if appropriate 3/ place haemostatic agents into surrounding tissues.
- The working time for MTA is about 5 minutes, however, this is dependent on various factors. As you are mixing it, water starts to evaporate from the reacting mass as well as being consumed by the MTA powder. So the workability dramatically changes in a short period of time. If you want to extend the working time, you can cover your MTA with wet gauze so the water will not evaporate or some sort of very small cup to cover the freshly mixed MTA.
- The mixing of MTA is hard to nail on the first go. You should know how to use it before you use it, otherwise it can be a very expensive material. I recommend that you practice mixing and handling portland cement to simulate a case prior to using MTA on a patient. The instructions for use state 3 parts power, to 1 part water. But this is by mass and these small quantities are almost trivial to use scales. Also, the moment you mix it, some of the water will start evaporating. If you’re taking too long to fill the defect, you will have to add more water to make the MTA workable again. Dispense as much as you think you need to just fill the defect. You can dispense it on a glass slab or on a paper mixing pad. If you use a mixing pad, it’s very easy to accidentally tap the pad and have the paper fling up your powder, so I recommend the mixing glass slab
- You can slowly move small amounts of water towards the powder until you get the mix you want. It’s handy to have 2 cotton rolls nearby. One of which is dry and the other is wet. If your mixture is dry, squeeze the wet cotton roll and it will release water more gently than if you were to use your triplex. If your mixture is too wet, you can use the dry cotton roll to dab the MTA and the roll will suck up the excess water. When you mix the material, you want something that you can pick up well with your flat plastic or small spoon excavator. If it easily falls off, it’s either too wet and drips off, or is too dry and crumbles off.
- If you don’t have any distilled water on hand, or feel like using alternative solutions, keep in mind they can influence the way your MTA sets. If the material does not completely set, the seal of the tooth may become compromised over time. Accelerators often lead to weaker final strengths. So, using saline or sodium hypochlorite is less ideal than using distilled water because the final strength might be weaker, but at least you know it has set. This far beats the concern of using retardants such as local anaesthetic or chlorhexidine gluconate where your MTA has not set, and may leak out from your tooth with time leaving voids.
- (wait 3 seconds)
- In pulpotomies, you’re basically filling the whole pulpal chamber with MTA. It’s a comparably large quantity of material. To help dispense it, you can use amalgam carriers, or pick up the MTA using spoon excavators or flat plastic instruments. Once it’s in, a damp cotton pellet held by your tweezers can be used to compact your MTA.
- (wait 3 seconds)
- For deeper and smaller defects, the amalgam carrier can be clumsy. The MAP system, costs around a $870 dollars. You can get it from either Gunz or Dentsply. It comes in various head shapes that you connect to the syringe. There are other carriers out there that range from 80$ to 200$. I haven’t used the cheaper ones but they’re worth a look. The reason why these carriers have lost popularity with endodontists is because if you leave the MTA in the carrier after the appointment, you may find the tip will be clogged with hardened MTA and the carrier cannot be used again. If this happens to you, drop the tip into vinegar and when you have spare time, stick a stainless steel size 20 K File into the orifice and twist. This will scrape and brush out the MTA. It may take up to 15 minutes to remove depending on how long you left the MTA to set.
- One of the best uses for the MTA carrier is apexification. If you’re performing a root canal where the apex is larger than a 55 K-File you should probably start thinking about using MTA at the end of the apex. There’s a few methods to pack MTA down an apex. To place MTA into the apical third, you need to length control the placement. It’s very rare that you will significantly extrude any MTA as there is usually some sort of tissue at the apex that will block the extrusion of gently applied MTA. If you DO extrude MTA, it’s biocompatible so it’s unlikely to cause any problems.
- If you don’t want to spend money on those carriers, you can use a Lee block. I hear you can buy it from dentsply but I’m yet to come across it. It’s very popular amongst endodontists. Once you finish mixing your MTA you smear it against the slots which compacts the MTA into vertical pillars. You can then use a half hollenback or anything similar to pick up the MTA. If you fill a few slots up at once it means you can pick up a few pillars of MTA in a quick sequence.
- You can create your own Lee block using a block of plastic and a fissure bur. If you’ve attended hands on endodontic courses you will come across plastic blocks. You can glue a microbush onto the block to create your own handle.
- If your MTA doesn’t go all the way down to the apex, you can use a Buchanan hand plugger, glick plastic plugger, or any flat ended straight probe like hand instrument to push the MTA further down. In the picture you can see an ultrasonic tip being used to transmit vibrations to the plugger to jackhammer the MTA down. This can be helpful to push your MTA further down. It’s used without water spray and many clinicians get their dental assistant do hold it up against the plugger. However, the collisional vibrations on the MTA can disrupt the setting structure, reducing micro-hardness and create porosities if ultrasonics are applied for over 2 seconds.
- Once you place MTA down the canals you’re very like to have left over MTA smeared up against the dentinal walls. You can use paperpoints to clean the walls but you may find your paper points aren’t applying enough pressure against the walls to remove all the residue. Alternatively, you can get your K files and twist them in a cotton roll until they get a layer of cotton roll on it, as seen on the right hand side. With this, you can apply pressure against the wall, more so than a paper-point and you can provide more effective twist forces against the wall to wipe MTA off the walls. Otherwise, MTA can be removed from tooth walls using gentle brushing using cotton pellets, micro-brushes, gentle irrigation with water or using irrigation via ultrasonics.
- Much of the historic literature on MTA utilizes a method where a damp pellet followed by Cavit is placed above the MTA to protect the material as it slowly set. However, temporizing a tooth with cotton pellets delays completion of the restoration and can compromise the quality of the seal. It is now common to gently place GIC, RMGIC or even resin bonding agents onto MTA. Once these materials have set, you can then restore the rest of the tooth with composite resin.
- Are there any questions on the placement of MTA? (Drink water again)
- Vet chemicals that are supplied for use in the prevention and treatment of animal diseases must be registered by the APVMA. Therefore, if you are going to use MTA that isn’t ProRoot MTA or MTA Angelus, just be careful with the APVMA.
- Whether you’re using, MTA, or something concocted within your own practice, be mindful of the choice of words you use – you don’t want to be overheard by members of the public or uneducated nurses that you’re placing concrete in an animal’s tooth. You also don’t want to be seen making cement using a bag of Portland cement from bunnings. Imagine the front page of the local newspaper stating that local vet being caught using portland cement. Or, having the crew from A Current Affair chasing you down. Legal or not, it would ruin your practice.
- There are scientific studies in animals AND people illustrating comparative results between MTA and Portland Cement. Despite these studies finding that Portland cement can be used in dentistry, regulation will never allow an industrial product to be used in medicine as quality assurance in industry is for industrial purposes, not for medical purposes. Furthermore, Portland Cement is not radiopaque and therefore fails radiopacity standards for dental restorative materials.
- MTA is made by mixing two powders, 80% Portland cement and 20% Bismuth oxide. As I mentioned earlier, bismuth oxide is a contributor to the eventual blackening of a tooth. To achieve a similar level of radiopacity the following percentages of alternative powders can be used. 30% Zirconia oxide - 30% Zinc Oxide, 30% Barium sulfate 10% gold or 10% silver tin alloy. It may seem ridiculous and expensive to use 10% gold but MTA costs more per gram than gold. If you made your own MTA using gold it would still be cheaper than MTA. The larger the amount of MTA stored in a jar, the less likely the mixing of the powders will be homogeneous. At present, the largest commercial brand of MTA, MTA Plus from India, is supplied in 8g jars. Therefore, I suggest if you are going to make your own MTA, to stick to quantities lower than 8grams per jar.
- (pause 3 seconds)
- If you’re going to use the ProRoot satchels and want to use them for multiple uses, consider pouring them into small jars to protect the powder. Otherwise, use MTA angelus which comes in jars. If you leave your MTA powder exposed, the cement particles will combine with the water in the air to produce larger pre-hydrated, semi-set cement particles leaving you with a cement which is clumpier, harder to mix, and less likely to properly set.
- Do not store your MTA in the fridge. The simple science is, the colder your MTA, the slower it will react with water increasing the risk of fluid contamination and hence weaker properties. So, don’t store your MTA in the fridge.
- If you would like more information on the handling of MTA, you are welcome to read my paper in the journal of the canadian dental assocation. I do run a website called mineral trioxide aggregate.com, however, it’s some what of a neglected website so the powerpoint you’ve seen today, as well as your lecture notes, has better information. If you would like a copy of my powerpoint presentation, please email me at W. H A @ U Q . E D U . A U
- Here are my references – which are in your lecture notes too.
- Thank you for your attention. Are there any questions?