Adherent calcifications do represent a significant challenge when one is trying to locate the root canal entries during the procedure. This patient was referred for a pre prosthetic root canal treatment on a calcified first maxillary premolar. In this case, the pulp chamber was completely obliterated by adherent calcifications as well as the root canal entries. Furthermore the root canals are also narrow.
The first step consisted in finding the pulp chamber floor position. A challenging task when the pulp chamber is completely obliterated. In order to estimate its depth as well as its location, the CEJ has been used as the ultimate guide (Using Krasner’s and Rankow’s both law of centrality and law of concentricity). Unfortunately, despite the fact that the approximate depth corresponding to the CEJ level has been reached, the narrow root canal entries were still obscured by reparative dentine. (Figure ).
Therefore, in order to limit the risks of tooth excessive destruction or perforation, a small volume 3D Scan was performed to display their exact location. While the coronal CBCT slice showed that the correct depth had been reached, the axial CBCT plane showed that, in palatal root, an extra 2mm of dentine had to be removed toward the palatal and also one mm troughing in the vestibular direction in the buccal root was necessary before entries could be reached.
A microscope and a Variolux NSK handpiece with a diamond coated tip has been used for that purpose. Once the root canal entries were located, the first instruments (Mani K files number 06) were reaching the apical constriction in both canals. Shaping with Mani K files and ProTaper Universal. Obturation with Pulp canal sealer from Kerr and gutta.
In this case, the microscope alone could not be used in order to locate the root canal entries. Krasner and Rankow laws helped in reaching the pulp chamber floor level, then, both CBCT and the microscope had to take over in order to finally be able to locate the entries.
Adherent calcifications do represent a significant challenge in endodontic procedures. According to this study: “as the extent of canal calcification increased one level of intensity, the difficultly in reaching the root canal constriction increased 7 times.”