MTA carrier. The mineral trioxide aggregate (MTA) is a dental material with biocompatibility properties to oral and dental tissues. MTA was developed for dental root repair in endodontic treatment and it is formulated from commercial Portland cement, combined with bismuth oxide powder for radiopacity. MTA is used for creating apical plugs during apexification, repairing root perforations during root canal therapy, and treating internal root resorption. It can be used for root-end filling materia