Root canal failure is very rare, accounting for only about 5% of all root canal procedures. However, if your first root canal treatment is not successful, the tooth can still be saved via endodontic retreatment or an apicoectomy. During retreatment, the previously placed filling material is removed, the canal cleaned again, and the tooth refilled and resealed. An apicoectomy removes the infected tissue by going through the tooth’s root, then seals the root.