Teeth that have had a root canal treatment can last a long time and never need further endodontic treatment. However, occasionally, nonsurgical endodontic treatment alone cannot save the tooth. In these cases, endodontic surgery may be recommended. 

Endodontic surgery may be required when calcific deposits make the root canal too narrow for the instruments used in nonsurgical root canal treatment to reach the end of the roots, in these cases endodontic surgery can clean and seal the remainder of the canal. It may also be recommended to locate hidden canals, to repair damaged or resorbed root surfaces or to explore the root for presence of root fracture.

There are different surgical procedures that can be performed to save a tooth, but the most common one is called apicoectomy or root-end surgery. This procedure usually involves making an incision in the gum tissue to expose the bone and surrounding inflamed tissue around the root ends. The damaged tissue is removed along with the end of the root tip. A root-end filling is usually placed to prevent reinfection of the root and the gum is sutured. The bone naturally heals around the root over a period of months restoring full function. Local anesthetics make the procedure comfortable, and most patients return to their normal activities the next day. Postsurgical discomfort is generally mild.

Often, the alternative to surgery is extraction of the tooth. The extracted tooth must then be replaced with an implant, bridge, or removable partial denture to restore chewing function and to prevent adjacent teeth from shifting.