Endodontic treatment involves removing diseased tissue from the root canal system of a tooth, as well as preventing re-infection of the root canals. Therefore, root canal treatment is necessary in situations of irreversible damage or necrosis of the tooth pulp. The most common disease-related causes that require root canal treatment include dental caries that have led to irreversible pulpitis. In addition, root canal treatment is performed in cases of tooth trauma and when preparing teeth for prosthetic restorations. If a tooth is not adequately strengthened, the placement of a ceramic crown or bridge may not be possible or may lead to further tooth damage. Other indications for endodontic treatment include inflammation of the periapical tissues (e.g., periapical lesions, granulomas, cysts), as well as periodontal diseases (endoperio lesions). Teeth that have been previously improperly treated with root canal treatment may also require retreatment, which is known as reendo..