Endodontic treatment is indicated for deep caries when the disease progresses to the pulp and then to the periodontium. The inflamed paranasal ligament in the periodontal crevice gradually disintegrates, the gums around the apex are saturated with pus, which spreads to the periosteum. The tooth becomes loose because of this, and if the periodontal disease is not treated, canal cleaning will not help and it will be necessary to remove it either completely or partially.

Other indications for treatment are fracture or dislocation of the tooth and preparation for metal-ceramic prosthesis. In order for the root to support the prosthesis, the endodontist inserts pins into the canals, which support the tooth walls and distribute the stress evenly.

Endodontics is contraindicated if the periodontium is thinned or the coronal part is destroyed and cannot be restored. Cleaning and treatment are also contraindicated in cases of acute or chronic oral mucosal disease and when access to the affected tooth is difficult and canals are technically complex to treat.