Peri-radicular inflammation related to dens invaginatus treated without damaging the dental pulp: a case report.

A 12-year-old boy was referred with a discharging sinus tract related to the maxillary left lateral incisor, and with a non-vital maxillary left central incisor. The lateral incisor gave a positive response to sensitivity testing. The lesion did not heal after disinfection of the root canal of the central incisor, but healed subsequently after 'endodontic' treatment of an invagination in the lateral incisor. After 2 years the lateral incisor continued to give a positive response to sensitivity testing.