Mineral Trioxide Aggregate as Furcal Perforation Repair Material:A Review

INTRODUCTION

In endodontic practice furcation perforation is one of the most common procedural errors which has a detrimental impact on the treatment prognosis and often leads to failure of endodontic treatment.1Perforation is defined as mechanical or pathological communication between the root canal space and external tooth surface leading to injury to periodontium leading to inflammation ,destruction of periodontal fibres, bone resorption leading to formation of granulation tissue ultimately leading to periodontal disease. Perforation can occur at any area of root surface. Therefore repair of the perforation becomes necessary to improve the treatment outcome. One of the suggested approach to repair furcation perforation is the non-surgical approach i.e. sealing the furcation with a non-irritating, anti-bacterial, radio-opaque, insoluble in oral fluids, dimensionally stable and biocompatible material with a potential to form hard tissue barrier under the material in the treated teeth. Various materials like GIC, IRM, MTAD, amalgam were used in past but MTA a novel material has a greater repair potential.

MTA: Chemical Composition & Characteristics

Torabinejad et al (1993) introduced Mineral Trioxide Aggregate (MTA) and developed as a material for repair of root perforations2. MTA is a hydrophillic cement which sets in presence of moisture3. It becomes a colloidal gel when mixed with water and then solidifies resulting in formation of hard structure4.

MTA is available in powder and liquid form. The powder liquid ratio of MTA is 3:1.The powder consists of fine particles of ‘tricalcium silicate’, ‘tricalcium oxide’, ‘tricalcium aluminate silicate oxide’ and traces of mineral oxides5. Bismuth oxide is the radiopacifying agent. The setting time of MTA is approximately 3-4 hours. The initial pH of MTA is 10.2 later raises to 12.5 after final set thereby making it a material with excellent antimicrobial characteristics6. The compressive strength of at 24 hours is low i.e. 40MPa which increases to 67MPa after 21 days. The particle size ranges from 0.1 µm to100 µm and the average particle size is 10µm. The ‘tricalcium oxide’ in powder reacts with tissue fluid and forms ‘calcium hydroxide’ which results in formation of hard tissue barrier.

Clinical Implications as repair material

Various materials for repair of furcation perforations are available, however, at present the material of choice is MTA which has been shown to induce cementum formation in the involved region. Microscopic studies have showed that upon sealing the perforation with MTA, inflammation in periodontium reduces, healing and repair process takes place and subsequently forms cementum under the material.7 In addition, the expression of oesteocalcin gene was observed after the application of MTA. MTA increases both proinflammatory and anti inflammatory cytokines from osteoblast.

Bioactivity

MTA is considered as a bioactive material attributable to its osteoinduction potential8.MTA also provides an effective seal against penetration of bacteria and their by-products9. Bonson et al demonstrated that MTA is capable of modifying fibroblastic differentiation resulting in increased activity of alkaline phosphatase which is regarded as an indicator of bone formation, thereby promotes hard tissue formation10

Antibacterial Activity of MTA

Antibacterial activity and ability to form hard tissue has been attributed due to the alkaline pH of set MTA that is 12.5 after 3 hours.11

Sealing Ability

Studies conducted by Fogel and Peikoff showed MTA prevents microleakage, has exceptional sealing ability and proves to be an excellent material for perforation repair12. However the main drawback of MTA is its poor handling characteristics and discoloration potential.

Biocompatibility and cytotoxicity

Koulaouzidou et al found that MTA has less cytotoxic potential and considered as biologically inert material13.

SEARCH METHODOLOGY

A review of literature on “furcation repair material” was performed by utilizing information published in various ‘peer reviewed journals’ ,’MEDLINE’ and other sources. The relevant information regarding “furcation repair material” was searched using manual as well as electronic search methods and related articles were thoroughly analyzed and considered for this literature review.

CONCLUSION

At present MTA exhibits all characteristics of an “ideal perforation material”, and can be considered better material owing to its characteristics such as superior sealing ability, excellent biocompatibility and an osteoinduction potential. The current literature attempts to provide a baseline knowledge for MTA as furcation perforation repair materials but further studies and clinical trials are required to improve upon their properties.

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