MTA - The Wonder Material

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Released: 6/1/2013   Expires: 12/1/2015
About the Author

Dr. Amy Dukoff earned her dental degree at Tufts University School of Dentistry and her Certificate of Endodontics from Kingsbrook Medical Center. She was a clinical assistant professor at Columbia University for ten years, where she taught Oral Diagnosis and Endodontics. She has lectured on endodontics throughout the US. Currently, she is president of the American Association of Women Dentists and Secretary of the Carnegie Study Club.

Dr. Dukoff has no financial interest in or affiliation with any company or product mentioned in this lesson.

Objectives

After completing this lesson, you should be able to identify:

  1. What the abbreviation MTA stands for
  2. The chemical composition of MTA
  3. The reason for adding bismuth trioxide to MTA
  4. The steps in the hydration of MTA
  5. The chemical result of the hydration of MTA
  6. The primary endodontic uses of MTA
  7. The effectiveness of MTA in cases where there is pulpal necrosis
  8. An advantage of MTA over other treatment options
  9. The effect on tissue of extruding MTA beyond the apex
  10. Two advantages of MTA in treating the immature apex
Audience
  • General Dentists
  • Endodontists without experience using MTA
Overview

Mineral trioxide aggregate, abbreviated MTA, has its origins in Portland cement, a basic ingredient of concrete, stucco, and grout. At Loma Linda University in California, Dr. Mahmoud Torabinejad developed MTA as a material for repairing root perforations and filling root-end openings. Later, Tulsa Dental produced MTA commercially as ProRoot MTA and other products.1 The FDA approved it in 1968.2 It is well known for its excellent sealing ability. It useful as an apical plug for immature or open apices and in pulp-capping. It has been enormously successful in sealing internally in the pulp chamber and along the root canal wall. As a barrier seal, it has proven its outstanding ability to prevent microleakage. Its usefulness in clinical practice spans from apexogenesis to sealing perforations.

Chemical Composition

Basically, mineral trioxide aggregate consists of calicium, silicon, and aluminum derived from limestone, hydrated lime, gypsum, and potassium aluminium silicate. MTA for dental use is composed of tricalcium silicate, dicalcium silicate, and varying amounts of tricalcium aluminate, calcium sulfate, and bismuth oxide.3 In order to make MTA visible by radiograph, bismuth trioxide is added for its radiopaque properties. MTA is available in white and gray. They differ because the gray material has iron in it while the white does not.

Hydration of MTA

The hydration of mineral trioxide aggregate is a two-step process. The first step is the reaction between tricalcium aluminate and water, which forms ettringite. The second step is the reaction between tricalcium silicate and dicalcium silicate and water, which forms calcium silicate hydrate gel and calcium hydroxide. The calcium hydroxide that is produced in the second step creates an alkaline environment and is released into the neighboring tissue. The release of calcium by hydration has been associated with the production of hydroxyapatite.4

Sealing the Apex with MTA

Sealing the apex with MTA is a viable option with documented success. Doctors Pari Ghaziani, Navid Aghasizadeh and Mahshid Sheikh-Nezami in their paper, Endodontic treatment with MTA apical plugs: a case report, conclude that using an apical plug of MTA is a good treatment option for open apices. They found that MTA used as an apical plug reduced the treatment time that was needed as compared to the time apexification took with calcium hydroxide. Their case demonstrated that an apical plug of MTA can be used in cases where there is pulpal necrosis.5 The MTA apical plug is a useful treatment option for sealing open apices.

Effects of Extruding MTA Beyond the Apex

When MTA is placed as a plug to seal the apex, there is obvious concern about extruding MTA past the apex: how will the material be accepted by the tissue? In Long-term observation of the mineral trioxide aggregate extrusion into the periapical lesion: a case series, Doctors Chang, Oh, Lee, Cheung, and Kim, evaluated the effects of MTA that was extruded past the apex. They based their evaluation on a series of case reports. They determined that MTA did not negatively affect the periapical tissues’ healing. Also, they determined that even when the open apex was infected there was healing and resolution of the periapical area, so that MTA could be utilized successfully. MTA proved to be a valuable material for creating a successful barrier to seal open apices.6

MTA’s Advantage in Treating the Immature Apex

The use of MTA as a root-end closure in immature apices should be considered as an alternative to the traditional calcium hydroxide apexification technique. Creating an artificial barrier that is biocompatible is a necessity when treating the immature apex. Establishing a hard apical barrier is necessary in order to obturate the pulpal chamber. MTA is biocompatible, and it has the ability to stimulate hard tissue formation. Furthermore, normal periodontal ligament space has been found after mineral trioxide aggregate placement.

One-Visit Treatment

The use of MTA as a root-end closure in immature apices should be considered as an alternative to the traditional calcium hydroxide apexification technique. Creating an artificial barrier that is biocompatible is a necessity when treating the immature apex. Establishing a hard apical barrier is necessary in order to obturate the pulpal chamber. MTA is biocompatible, and it has the ability to stimulate hard tissue formation. Furthermore, normal periodontal ligament space has been found after mineral trioxide aggregate placement.

NOTE: Because this course has not provided you with supervised clinical experience in the technique or procedure taught, completing it does not ensure that you have attained clinical competence. Be aware that using limited knowledge when incorporating techniques and procedures into your practice carries potential risks.

Resources for Further Study
  • Castellucci, Arnaldo. The Use of Mineral Trioxide Aggregate in Clinical and Surgical Endodontics. Dentistry Today. http://www.dentistrytoday.com/endodontics/1099-the-use-of-mineral-trioxide-aggregate-in-clinical-and-surgical-endodontics. Last accessed May 30, 2013.
  • Agarwal A, Mala K, Malhotra N, Mineral trioxide aggregate: a review of physical properties. dentalaegis.http://www.dentalaegis.com/cced/2013/02/mineral-trioxide-aggregate-a-review-of-physical-properties. Last accessed May 30, 2013.
  • Agarwal A, Mala K, Malhotra N, Mineral trioxide aggregate: part 2 - a review of the mineral aspects. dentalaegis. http://www.dentalaegis.com/cced/2013/02/mineral-trioxide-aggregate-a-review-of-physical-properties. Last accessed May 30, 2013.
References
  1. Camilleri, Josette. J Conserv Dent. 2008 Oct-Dec; 11(4): 141.doi: 10.4103/0972-0707.48834
  2. Schwarts RS, Mauger M, Clement DJ, et. al. Mineral trioxide aggrgate: a new material for endodontics. J AM Dent Assoc. 1999; 130:967-975.
  3. Camilleri J. The chemical composition of mineral trioxide aggregate. J Conserv Dent 2008;11:141-3.
  4. Camilleri J. The chemical composition of mineral trioxide aggregate. J Conserv Dent 2008;11:141-3.
  5. Ghaziani, et.al., Endodontic treatment with MTA apical plugs: a case report, Journal of Oral Science, Vol. 49, No. 4, 2007, page 328.
  6. Chang, Oh, Lee, Cheung, Kim, Long-term observation of the mineral trioxide aggregate extrusion into the periapical lesion: a case series, (2013) 5,54-57. International Journal of Oral Science.
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Musikant & Deutsch, D.M.D. P.C. is an ADA CERP Recognized Provider

November 2013ADA CERP is a service of the American Dental Association to assist dental professionals in identifying quality providers of continuing dental education. ADA CERP does not approve or endorse individual courses or instructors, nor does it imply acceptance of credit hours by boards of dentistry. through December 2015

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