Root canal therapy is the process of removing infection and disease from the root of a tooth. If a root canal is not performed on an infected tooth, the infection could spread to the rest of the tooth and the entire tooth will need to be extracted. During a root canal, the inside of your tooth is cleaned and filled with a filling. After a root canal, the doctor may recommend restorative procedures including a post & core and crown, which will help to return your mouth to good oral health.