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.