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 (α ≤ 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.