Influence of adjacent teeth restored with metal posts in the detection of simulated internal root resorption using CBCT.

AIM: To assess the influence of artefacts generated by metal posts on the detection of simulated internal root resorption (IRR) in adjacent teeth using cone-beam computed tomography (CBCT) and to verify the impact of metal artefact reduction (MAR) on these cases. METHODOLOGY: CBCT images of 14 premolar teeth were acquired before and after IRR simulation using chemical and mechanical procedures, in an OP300 Maxio unit, with and without MAR. Each tooth was placed in the socket of a human mandible and scanned under three different conditions: (i) without adjacent teeth - control group; (ii) distal adjacent tooth restored with metal post; and (iii) with both adjacent teeth restored with metal post. Five oral radiologists scored the IRR detection using a 5-point scale. Diagnostic values were obtained for the tested groups and compared using two-way analysis of variance (α = 0.05). RESULTS: The presence of a single adjacent tooth restored with metal post did not significantly influence the diagnostic values for IRR detection (P > 0.05). The presence of both adjacent teeth with metal posts, without MAR application, was associated with a significantly lower area under the ROC curve (Az) compared to the control (P = 0.0182). In this case, the application of MAR increased Az, leading to nonsignificant differences from the control group and the group with one adjacent restored tooth (P > 0.05). Sensitivity decreased significantly when two adjacent restored teeth were present, regardless of MAR application (P = 0.0379). Specificity was not affected by the conditions tested (P > 0.05). CONCLUSION: CBCT detection of IRR was impaired by artefacts only when both adjacent teeth restored with metal posts were present. In such cases, activation of MAR improved the performance on this diagnostic task.

Root canal configuration and its relation with endodontic technical errors in premolar teeth: a CBCT analysis.

AIM: To evaluate the association between endodontic technical errors and the root canal configuration (RCC) of human premolars, as well as their relationship with periapical lesions through cone-beam computed tomography (CBCT) images. METHODOLOGY: The sample consisted of CBCT scans belonging to 136 patients, totalling 152 root filled premolars (185 roots). CBCT images were evaluated by two oral radiologists. RCC was recorded according to Vertucci's classification, and the endodontic treatment quality was judged on the presence and type of technical endodontic errors (underfilling, overfilling, nonhomogeneous filling, nonfilled canal, fractured instruments, root deviation and absence of coronal restoration). In addition, the presence of periapical lesions associated with each RCC was recorded. Data were expressed by frequencies and percentages, and intraobserver agreement was calculated using the Kappa test. RESULTS: The most common RCC was type I (71%), followed by type IV (15%), type II (8%), type V (3%), type VI (1%) and type III (1%). Types VII and VIII were not observed in the sample. Underfilling was the most frequent endodontic technical error for most RCCs, except for types IV, V and 'other', whose most frequent error was a nonfilled canal. The presence of technical errors was greater with an increase in the proportion of the periapical lesions. The intraobserver agreement was excellent. CONCLUSIONS: There was an increase in the prevalence of endodontic technical errors and in the presence of periapical lesions as the anatomical complexity of the root canals increased. Underfilled and nonfilled canal were the most frequent endodontic technical errors.