NONSURGICAL ENDODONTIC TREATMENT OF OEHLERS’ TYPE III DENS INVAGINATUS USING CONE-BEAM COMPUTED TOMOGRAPHY AND SURGICAL OPERATING MICROSCOPE

Abstract

Dens invaginatus (DI) is an abnormality in which the tooth’s enamel surface and dentin fold inward toward the dental pulp, often creating a tooth within a tooth. In extreme cases, this abnormality can extend from the crown to its periodontal membrane at the base of the root. The present case is such an extreme case, and was therefore diagnosed as Oehlers’ type III. X-ray showed a thumb head-sized radiolucency on the root’s mesial surface, but tests showed that the dental pulp was still viable. As root canal treatment of similar cases is difficult, extraction is typically the only treatment. In this case, however, a maxillary lateral incisor with Oehlers’ type III invagination’s location was detected by cone-beam computed tomography (CBCT) prior to treatment. Subsequently, using a surgical operating microscope (SOM) and an ultrasonic tip, the invaginated enamel was removed successfully without damaging the tooth’s healthy parts, and then root canal preparation was initiated. By packing mineral trioxide aggregate (MTA) into the root canal, the dental pulp was saved and the inflammation around the tip of the DI was treated successfully. In treating DI, it is necessary to accurately assess and very precisely treat without destroying the surrounding dental tissue; thus, CBCT and SOM are very useful.