Chemical composition of Mineral Trioxide Aggregates (MTA): A review of literatures

In 1993, Mineral Trioxide Aggregates (MTA), a grey-colored material was introduced to dentistry. A similar product in white-color was also produced later. The aim of this study was to review the literature in order to compare the chemical composition of these two different types of MTA. Over 600 articles have been published about the properties of MTA, 33 of which were about chemical and 28 were on its physical properties. In addition, about 80 articles have been published on similarities and differences between MTA and Portland Cements (PC). This article reviews the history of MTA’s manufacturing, its introduction to market, its patent, its commercial brands, and its similarities with PC. We also reviewed size of powder particle, setting form, and also hydration reaction of MTA. Mainly consisting of CaO and SiO2, MTAs and PC have similar compositions. MTA also contains Bi2O3 as an opacifier. The main difference in chemical composition of white MTA and PC with grey MTA is that the latter contains less amount of some minor elements specifically FeO. White MTA has finer particles and crystals compared to the grey one. No phosphate does exist in MTA composition, but during the hydration, this material is able to release calcium and hydroxyl ions which, in reaction to exogenous phosphate, results in hydroxyapatite formation. Both MTA and PC are hydrophilic cements. Regarding the biocompatibility of these materials, MTA is considered suitable for clinical applications; while no permission exists for clinical use of PC.