What is a root canal retreatment?
With proper care, teeth that have had root canals can last a lifetime but sometimes, a tooth that has been treated doesn’t heal properly, either due to complex anataomy of the tooth which provided a challenging or can become re-infected through new decay, a fracture or a loose, cracked or broken filling or crown. In addition, a tooth may not have healed as expected for a variety of reasons such as narrow or curved canals, complicated tooth anatomy, a restoration that did not prevent salivary contamination, or a delay in getting the crown or restoration following treatment.
During retreatment, the endodontist will reopen the tooth from the top and remove the gutta percha filling material placed during the first root canal procedure.

He or she will then examine the tooth for possible additional canals and/or new infection and will then proceed to remove any infection, clean and shape the canals just as a regular root canal and place new gutta percha inside. The opening will then be sealed with a temporary filling again.