Multifaceted Use of ProRoot MTA Root Canal Repair Material

Date: 10/27/2010

Resident: Cho

Author(s): Schmitt et al.

Journal: Pediatric Dentistry

Year. Volume (number). Page #’s: 2001. 23. 326-330.

Major topic: ProRoot MTA

Minor topic: Root Canal Repair

Type of Article: Review Article

Main Purpose: The purpose is the review MTA’s physical and biological properties and the clinical techniques of direct pulp capping, apexification, and repair of failed calcium hydroxide therapy.

Overview of method of research: Review of research studies

Findings: MTA is an ash-colored powder made of fine hydrophilic particles of tricalcium aluminate, tricalcium silicate, silicate oxide, and tricalcium oxide. When the material is hydrated it becomes a colloidal gel. The main components of MTA are calcium phosphate and calcium oxide. The material sets in 3-4 hours and bismuth oxide powder is added for radiopacity. The setting ability is uninhibited by blood or water. The pH of MTA when it is set is 12.5, which is similar to calcium hydroxide. MTA has a compressive strength of about 70 MPA, which is approximately equal to that of IRM but less than amalgam (311 MPA). MTA also has some antimicrobial properties and low cytotoxicity. The biocompatibility of MTA has been found to be equal or superior to amalgam, IRM, and ZOE. In non-human studies of perforation repair using MTA, cementum was shown to grow over MTA with minimal inflammation, even when material was extruded beyond the perforation site. MTA stimulated the release of cytokines and production of interleukin. The price of one box of 5 one-gram packets with a carrier cost about $300 (each packet is for one-time use only). MTA can be used for direct pulp capping, repair of internal and external resorption, root end filling, apexification, and repair of root perforations.

In direct pulp capping, once caries has been removed, irrigate with NaOCl for 5-10 minutes to achieve hemostasis of the pulpal exposure. Rinse out NaOCl and place 1-1.5mm layer of MTA directly over the exposed pulp. Place wet cotton pellet over the MTA and temporize. After one week, the proper setting of MTA should be verified and a final restoration can be placed directly over the MTA. The patient should be followed up in six months.

In apexification, after extirpirating the pulp and canals, irrigate with NaOCl. Place CaOH in canals to disinfect the canals. After one week, rinse canals with NaOCl, then place 3-4mm MTA in the apical end of the root to form an apical plug. Take an xray to confirm the fill. Place a moist cotton pellet and temporize. After one week, the canal can then be obturated and then should have radiographic and clinical re-assessments every 2-3 months. MTA is non-resorbable and shows excellent marginal adaptability which makes it a more superior material for apexification as opposed to CaOH. Also, with MTA, apexogenesis of immature root apices can be stimulated. MTA in the repair of failed calcium hydroxide therapy can be used in a way much like the method described for apexification.

Key points/Summary:

MTA can be used for immature permanent teeth that have a pulpal exposure due to caries or trauma. Animal studies and short-term clinical studies using MTA have shown to have good results. However, long-term studies still need to be conducted regarding MTA.

Assessment of Article:

Good summary of the composition of MTA and step-by-step explanation of how to use MTA for various circumstances. I agree that more research needs to be conducted to test the long-term success of MTA.