Nonsurgical Endodontic Management of Oehler's Type IIDens Invaginatus Using a Combined High- and Low-Viscosity...

Dens invaginatus (DI) is a developmental anomaly characterized by the invagination of enamel and dentin into the pulp space, predisposing affected teeth to pulpal and periapical pathologies. The complex and irregular canal anatomy often complicates endodontic management. This case report describes the nonsurgical endodontic retreatment of a maxillary lateral incisor (22) with Oehler's Type II DI in a 32-year-old female patient presenting with chronic apical periodontitis. Cone beam computed tomography revealed a highly complex root canal anatomy, consisting of a large, irregular main canal, numerous fine accessory canals, and multiple foramina associated with an extensive latero-radicular lesion. Treatment was performed under magnification and rubber dam isolation. The preexisting obturation material and part of the distal wall of the invagination were selectively removed to gain access to the root canal system. Owing to the inaccessibility of the true canal for mechanical instrumentation, disinfection was achieved exclusively through sonically activated irrigation. To manage the anatomical complexity, a novel dual-viscosity calcium silicate-based obturation technique was used, consisting of a low-viscosity tricalcium silicate sealer (BioRoot RCS), followed by incremental compaction of a high-viscosity tricalcium silicate cement (Biodentine). This approach aimed to allow the high-viscosity cement to obturate the large, irregular main canal while simultaneously driving the sealer into canal irregularities and accessory canals through the hydraulic pressure generated during its condensation. Clinical and radiographic follow-up at 18 months demonstrated evidence of periapical healing, supporting the success of the approach.