Teeth that have had root canal treatment can last a lifetime. Occasionally bacteria are left behind inside the complex anatomy of the pulp space during the initial endodontic treatment procedure sometimes causing a tooth that has been treated not to heal properly. These teeth can become painful or diseased months or even years after treatment. Bacteria can also cause a new infection in a successfully treated tooth if the previous root fillings are exposed by new decay or a cracked/broken filling/tooth. If a tooth failed to heal or develops new problems endodontic retreatment may be able to support healing and save the tooth.
During retreatment, the tooth is reopened and the filling materials that were placed in the root canals during the first procedure are removed. The tooth is then carefully examined looking for additional canals or new infection and any deficiencies in the previous root canal filling are corrected. The root canals system is then shaped, cleaned and filled in the same way as with initial endodontic treatment.