Root Canal Retreatment is a dental procedure performed when a tooth that has previously undergone root canal treatment becomes infected or fails to heal properly. This can occur due to undetected canals, delayed placement of a crown, or new decay exposing the root canal filling. During retreatment, the dentist or endodontist reopens the tooth, removes the old root filling, thoroughly cleans and disinfects the canals, and then refills and seals them. A new restoration is placed to protect the tooth. Root canal retreatment offers a second chance to save the natural tooth and avoid extraction.