Abstract
BACKGROUND The presence of dens invaginatus (DI) complicates treatment of any tooth, from diagnosis to access cavity and biomechanical preparation and obturation. Reports of successful non-surgical management of DI type IIIB in maxillary lateral incisor are rare. Here, we report such a case, with three root canals and a long follow-up. CASE SUMMARY A 13-year-old female patient presented with mild pain in the maxillary right lateral incisor (#7) for 10-15 d. On examination, the tooth was slightly rotated, with slight tenderness on percussion and grade I mobility but with no caries, pockets or restorations and non-vital pulp (via vitality tests). Radiographic examination revealed unusual configuration of the tooth's root canals, with an enamel-lined invagination extending to the apex, suggesting the possibility of DI Oehler's type IIIB and a periapical radiolucency. Widening the access cavity lingually revealed one distinct buccal orifice and two distinct palatal orifices; under higher magnification of a dental operating microscope (DOM), the mesio-palatal and disto-palatal orifices were observed as connected by a C-shaped groove. The root canals were prepared with hand K-files following a step-back technique, and obturated using a combination technique of lateral condensation and vertical compaction. At the 6-year follow-up, the patient was asymptomatic, and the periapical radiography displayed significant healing around the apical end of the root. CONCLUSION Proper knowledge of unusual root canal anatomy is required in treating DI. Conventional methods of root canal treatment can successfully resolve such complex cases, facilitated by DOM and cone-beam computed tomography.