Endodontic Re-treatment

Most teeth that have had root canal therapy heal uneventfully. In some cases, however a tooth that has had endodontic treatment develops a persistent or resistant infection. Occasionally, the tooth can become painful or diseased years after successful root canal therapy. If your tooth has not healed or has developed new symptoms, you may have a second chance at saving your tooth. Another procedure, root canal re-treatment, may be performed by your endodontist.

A previously root canal treated tooth may need a re-treatment for one of the following reasons:

  • During initial treatment, narrow or curved canals were not properly cleaned.
  • The final restoration was delayed following endodontic treatment.
  • The restoration did not protect the central portion of the treated tooth from salivary contamination.
  • A fracture of the crown or root occurs on the treated tooth.
  • New decay develops, exposing the canal to bacteria and a new infection.
  • Infection of the canal space occurs due to a loose or cracked crown or filling.


When re-treatment is necessary, your endodontist will re-open the tooth and remove the old root filling material. The canals will be thoroughly cleaned and carefully examined under a microscope to observe for cracks, decay, and infection. Once the canals are comprehensively cleaned, your endodontist will place a permanent root filling into the canal space.

After re-treatment is completed, you will again need to see your general dentist for the final restoration (filling or crown). If possible, preserving your natural tooth is always the best option. Teeth that have been restored with a filling or crown can last for years, even a lifetime.