When a cavity progresses to the live part of the tooth called the “pulp,” canal treatment must be performed. Canal treatment is performed under local anesthesia and aims to remove the infected tooth pulp causing pain and preserve the tooth in the mouth. It can be done in one session or multiple sessions in advanced cases. After the procedure, the tooth can be treated with filling materials and prosthetic coatings based on the amount of substance loss in the teeth. Teeth without canal treatment can experience inflammation, cysts at the root ends, swelling on the face, and severe pain. Teeth that are not treated for a long time will go to extraction treatment.