Non-surgical management of dens invaginatus type IIIB in maxillary lateral incisor with three root canals and 6-year follow-up: A case report and review of literature

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.