Introduction: An ideal orthograde or retrograde filling material should seal the pathways of communication between the root canal system and its surrounding tissues. It should also be nontoxic, noncarcinogenic, nongenotoxic, biocompatible, insoluble in tissue fluids, and dimensionally stable. Mineral trioxide aggregate (MTA) was developed and recommended initially because existing root-end filling materials did not have these "ideal" characteristics. MTA has also been recommended for pulp capping, pulpotomy, apical barrier formation in teeth with open apexes, repair of root perforations, and root canal filling. Since MTA's introduction in 1993, numerous studies have been published regarding various aspects of this material. The aim of Part I of this literature review is to present investigations regarding the chemical, physical, and antibacterial properties of MTA.
Methods: A review of the literature was performed by using electronic and hand-searching methods for the chemical and physical properties and antibacterial activity of MTA from November 1993-September 2009.
Results: There are many published reports regarding the chemical, physical, and antibacterial properties of MTA. Our search showed that MTA is composed of calcium, silica, and bismuth. It has a long setting time, high pH, and low compressive strength. It possesses some antibacterial and antifungal properties, depending on its powder-to-liquid ratio.
Conclusions: MTA is a bioactive material that influences its surrounding environment.