Inflammatory resorption caused by an adjacent necrotic tooth.

A case history is presented with a large periapical lesion and a perforating resorption defect on a cuspid. Endodontic therapy was performed, presuming that the necrotic cuspid caused the inflammatory response. No radiographic healing was evident 18 months after endodontic therapy. Considerable healing was demonstrated 6 months later, following the extraction of an adjacent tooth with prior root canal therapy. It was concluded that the failing root canal therapy of the extracted tooth was the primary factor leading to the inflammatory lesion, the resorptive perforation of the adjacent tooth, and its pulpal necrosis. It has not been reported prior that inflammatory resorption can result from the pulpal necrosis of an adjacent tooth.