A Rare Case of Type III Dens Invaginatus in a Mandibular Second Premolar and Its Nonsurgical Endodontic Management by Using Cone-beam Computed Tomography: A Case Report.

Invaginated teeth present technical difficulties in clinical management because of their abnormal anatomic configuration. Endodontic clinical management of type III dens invaginatus can be greatly enhanced by newer techniques and materials such as cone-beam computed tomography (CBCT), mineral trioxide aggregate, and platelet-rich fibrin. This case report presents a 13-year-old male patient with type III dens invaginatus (DI) in left mandibular second premolar with history of recurrent swelling. Pulp testing revealed no response with the tooth. Dens invaginatus type III with an immature apex and periapical lesion was seen on radiograph. The case was diagnosed as Oehlers type III DI with pulp necrosis and chronic apical abscess. The treatment was planned and performed by using CBCT imaging. CBCT was performed to see the canal anatomy and to know the size of periapical lesion. Root canal treatment was completed in 2 visits. Calcium hydroxide dressing was placed in the first visit. In the second visit MTA was used for apexification in the main canal, and warm vertical compaction technique with gutta-percha was used in the invaginated canal. At the 2-year reevaluation, the patient was asymptomatic, and his tooth had remained functional since the treatment was completed. Radiographic assessment of the tooth showed significant osseous healing of the preoperative lesion. Three-dimensional imaging is a valuable tool for endodontic management of teeth with complex internal anatomy.