Detection of various anatomic patterns of root canals in mandibular incisors using digital periapical radiography, 3 cone-beam computed tomographic scanners, and micro-computed tomographic imaging

Introduction The purpose of this study was to compare the accuracy of digital periapical (PA) radiography and 3 cone-beam computed tomographic (CBCT) scanners in the identification of various internal anatomic patterns in mandibular incisors. Methods Forty mandibular incisors were scanned using micro-computed tomographic imaging as the gold standard to establish the internal anatomic pattern. The number of root canals and internal patterns were classified into type I (single canal, n = 12), type Ia (single oval canal, n = 12), and type III (2 canals, n = 16). The teeth were placed in a human mandible, and digital PA radiography and 3 CBCT scans (Kodak 9000 3D [Carestream Health, Rochester, NY], Veraviewepocs 3De [J Morita MFG Corp, Kyoto, Japan], NewTom 5G [QR Srl, Verona, Italy]) were performed. Two blinded examiners classified each tooth's anatomic pattern, which were then compared with the micro-computed tomographic determinations. Results Considering type I and type Ia, which both presented with 1 root canal, there was a high degree of accuracy for all methods used (P >.05). The same result was found for type III. When identifying the shape of single canals (type I), CBCT imaging was more accurate compared with PA radiography. Concerning oval canals (type Ia), there was a significant difference between PA radiography and NewTom CBCT (PA radiography = 44%, NewTom = 88%). However, there were no significant differences between the 3 CBCT units. Conclusions Double-exposure digital PA radiography for mandibular incisors is sufficient for the identification of the number of root canals. All CBCT devices showed improved accuracy in the identification of single root canal anatomy when a narrow canal was present. However, the identification of oval canals was improved only with the NewTom CBCT device.