Mineral trioxide aggregate, MTA, is a cement material based on Portland cement with added bismuth oxide to confer radiopacity. It is now widely is used for a variety of applications in endodontic, including root‑filling and sealing. It is biocompatible in contact with human hard tissues and promotes both osteogenesis and cementogenesis at the root tip. MTA has good physical properties, and provides a durable seal for endodontically treated teeth. The setting reaction, based on hydration chemistry, is described and the biological properties of MTA are also covered. The review concludes that MTA is a useful and versatile endodontic material which gives good clinical outcomes.

Key words: endodontics, mineral trioxide aggregate, biocompatibility, root canal sealing.