Ex Vivo Detection of Apical Delta in Premolars: A Comparative Study Using Periapical Radiography, Cone-beam Computed Tomography, and Micro-computed Tomography

Introduction: Imaging methods are essential for the correct identification of root canal anatomy, which is a key factor for successful endodontic therapy. This study aimed to evaluate the performance of periapical radiography (PR) and cone-beam computed tomographic (CBCT) imaging in identifying the apical delta (AD) using micro-computed tomographic imaging as the gold standard. Methods: PR and CBCT images of 110 human premolars (120 root canals) were obtained using the VistaScan digital intraoral system (Durr Dental, Beitigheim-Bissinger, Germany) and the 3D Accuitomo CBCT unit (J Morita, Kyoto, Japan), respectively. Two oral radiologists assessed the PR and CBCT images for the presence of ADs using a 5-point scale. Additionally, in the CBCT images, the number of apical foramina was also evaluated. The gold standard was established by means of micro computed tomographic imaging. The diagnostic values related to PR and CBCT imaging were compared using the McNemar test. The detection of the number of foramina was compared using the paired t test (alpha <= 0.05). Results: ADs were present in 40 root canals (33.3%). Both PR and CBCT images differed significantly from the gold standard (P <.05) in the detection of ADs. CBCT imaging showed higher values than PR for all diagnostic tests (P <.05). Despite the moderate accuracy of PR (0.62) and CBCT imaging (0.73), these methods presented very low sensitivity values (0.07 and 0.35 for PR and CBCT, respectively). CBCT imaging had a tendency of underestimating the number of foramina (P <.05). Conclusions: CBCT imaging showed better performance than PR in the detection of ADs; both imaging modalities underestimate its presence when compared with the gold standard. In general, the number of apical foramina cannot be reliably assessed using CBCT imaging.