Management of Coronal Dens Invaginatus Using Nonsurgical and Surgical Approaches Assisted by a 3D-Printed Model: A Case Report

Coronal dens invaginatus (DI) is a developmental anatomical anomaly that forms during odontogenesis. A 12-year-old female presented to our clinic with a labial draining sinus tract associated with the maxillary right lateral incisor, which had persisted for several months. The patient reported no additional symptoms. Radiographic evaluation revealed a mid-radicular osseous defect involving the affected tooth. Cone beam CT (CBCT) confirmed the presence of a developmental anomaly, classified as Type 3a DI according to Oehlers' classification. Pulp sensibility testing of the lateral incisor was inconclusive, whereas all adjacent teeth responded normally. The tooth initially underwent nonsurgical endodontic treatment involving both the primary root canal and the invaginated canal. Treatment commenced after identifying a hypoplastic dentinal bridge separating the DI from the main canal. Management included placement of a mineral trioxide aggregate plug at the apex of the rudimentary root, which exhibited aberrant morphology. Although the draining sinus initially resolved following nonsurgical endodontic therapy, it recurred at the 12-month follow-up. Surgical treatment was then undertaken after generating a 3D-printed model to better understand the complexity and orientation of the anatomical anomaly, guided by CBCT imaging. Clinical review after surgical endodontic treatment at 12 months revealed resolution of the draining sinus. Radiographic evaluation showed a reduction in radiolucency, and follow-up at three years and 10 months demonstrated complete osseous repair of the latero-radicular lesion. Successful management of this case required both nonsurgical and surgical endodontic interventions. The incorporation of 3D printing facilitated surgical planning and contributed to improved treatment outcomes in teeth exhibiting complex anomalies such as DI.