Guided Endodontics Compared to Conventional Endodontic Treatment in Calcified Lower Incisors

The conventional access cavity was prepared under the microscope through the incisal edge as this approach facilitates straight-line access. A high-speed contra-angle handpiece, associated with a long surgical bur 010 (Meisinger, CO, USA), was used until the dentin was exposed, which is in general 3 to 4 millimeters from the incisal edge. Then, the ultrasonic tip ED5 (woodpecker-DTE, Guilin, China) was marked with a stopper according to the calcification level viewed on the preoperative CBCT and then used gently at the stopper level until the canal was found.

In all cases, digital and clinical protocols were followed according to the method reported by Zehnder et al. and Connert et al. The guide was replaced, and the access cavity precisely drilled using the EG6 drill, mounted on a low-speed contra-angle handpiece. With every 3 mm of progression, the cavity was rinsed, and the head of the bur was cleaned until reaching the canal. The irrigation was done to avoid overheating the dentine and the accumulation of dentine debris