Dental invagination is an abnormality of the crown or root development induced during tooth germ development when the enamel-forming apparatus or epithelial root sheath overpopulates and folds into the papilla. In severe cases, the invaginated channels are connected to the pulp and periodontal tissues, often causing endodontic and periapical diseases. The complex anatomical pattern of this disease adds difficulty in its preoperative diagnosis and clinical operation. In this paper, we report a case of non-surgical treatment assisted by cone beam CT and microscopy for maxillary lateral incisor double dens invaginatus type Ⅲ (Ⅲa and Ⅲb) with apical periapical infection. After 1-year follow-up, the affected tooth was asymptomatic and the periapical lesion was significantly reduced.
