Composition and Characteristics of Mineral Trioxide Aggregate (MTA) - MTA is formulated from commercial Portland cement. - It is combined with bismuth oxide powder for radio-opacity. - MTA is composed of tricalcium silicate, dicalcium silicate, tricalcium aluminate, tetracalcium aluminoferrite, calcium sulfate, and bismuth oxide. - White versions of MTA have been available since 2002. - Newly developed fast-set MTAs were developed by Pozzolan Cement or Zeolite Cement. - MTA is biocompatible with periradicular tissues. - It is non-cytotoxic and antimicrobial to bacteria. - MTA is non-resorbable. - It shows minimal leakage around the margins. - MTA has a high pH when mixed with water.

Usage of MTA in Clinical Cases - MTA is used for root-end filling after apicectomy. - It has better results in biocompatibility and micro-leakage sealing ability compared to other root-end filling materials. - MTA is not ideal due to drawbacks such as toxic heavy metal presence, discoloration, and difficult handling. - Other materials like glass ionomer cement, calcium phosphate cement, and calcium silicate-based materials are being developed for root-end filling. - These new materials are based on bioceramic or chemically bonded ceramic.

Root-End Filling after Apicectomy - An apicectomy may be required in persistent apical infections during root canal therapy. - MTA is retrogradely applied to the root tip cavity after resecting the root tip. - MTA is a refined Portland cement with better biocompatibility and sealing ability. - The benefits of MTA as a root-end filling material compared to other materials are inconclusive. - New materials like glass ionomer cement and calcium phosphate cement show promise as root-end filling materials.

Internal and External Root Resorption, and Obturation - In internal resorption, MTA is inserted in the canal to the level of the defect during root canal therapy. - Gutta percha and root canal sealer are placed above the defect to complete the treatment. - MTA provides structure and strength to the tooth by replacing the resorbed tooth structure. - In external resorption, MTA is retrogradely applied to the root surface after removing the defect during flap surgery. - MTA is used in direct cases to completely obturate the canal.

Other Uses of MTA - MTA Plus has the highest percentage of MTA in its formula. - Chitosan and gelatin are used as antiwashout agents in MTA root canal sealers. - MTA Angelus Fillapex sealer contains less than 20% tri/dicalcium silicate powder. - EndoSeal MTA and Tech BioSeal MTA are also MTA root canal sealers. - MTA Fillapex is a resin-modified root canal sealer. - Apexification is performed in incompletely formed roots to maintain the tooth position. - Apexogenesis allows pulp vitality during pulpal treatment for continued root development. - MTA can be used for mechanical exposure during cavity preparation in pulp capping. - MTA provides faster reparative dentin formation without pulpal inflammation.

Note: The "See also" section and other unrelated information have been omitted.