Mineral trioxide aggregate (MTA) is a cement type material that was introduced into field of endodontic in 1993 by Loma Linda University and has gained much popularity since. It is a material that has been used worldwide, with several clinical applications such as apical barriers in teeth with immature apices, repair of root perforations, root-end filling, direct pulp capping, pulpotomy and root canal filling material. Studies have demonstrated its capacity to stimulate cytokine release and interleukin production from bone cells, indicating that this material may actively promote hard tissue formation. This book gives a detailed knowledge of Mineral trioxide aggregate composition, its clinical applications and technique of placement. It also describes the physiochemical basis of biologic properties of MTA.