Nonsurgical re-treatment of endodontic failures.

Endodontic treatment has a very high percentage of success. When failures did occur, many were re-treated with surgery, although nonsurgical re-treatment often was an option. Recently, improvements in instruments for use in endodontic surgery have increased the ability to perform such re-treatments. Even so, this author believes that nonsurgical re-treatment is preferable to surgical intervention whenever possible because of the greater comfort to the patient and the increased indication of failure for amalgam reverse fillings. Advice for recall appointments and evaluations and the correct procedures for re-treating common failures without surgery are presented. These include failures caused by short or incomplete canal fillings, overextended canal fillings, untreated major canals, and chronically draining teeth.