Dr.Shanon PatelDEEMAH JUMAH ALALWANI2022-05-302022-05-30https://drepo.sdl.edu.sa/handle/20.500.14154/53230ABSTRACT Many CBCT machines are available in the market with different characteristics. This study aims to compare the accuracy of scans of four cone beam computed tomography (CBCT) scanners in assessing signs of disease at early stages; external cervical resorption and apical periodontitis. Two dry dentate human mandibles with thirteen teeth were obtained and used in this experiment. Simulated ECR and AP lesions were created on root surfaces and the base of the socket of extracted teeth, respectively. CBCT scans were taken before and after the creation of the lesions using four different CBCT units; Accuitomo (Morita), Orthophos (Sirona), CS9300(Carestream) and CS9600(Carestream)). Receiving Operator Characteristic (ROC) analysis, Kappa tests, sensitivity, and specificity were calculated for each CBCT scanner. The overall area under ROC curve for the four CBCT machines for ECR detection were 0.996 (Accuitomo), 0.992 (Orthophos), 0.979 (CS9300) and 0.985 (CS9600), and there was no significant difference (p<0.05). While the overall area under ROC curve for AP detection were 0.824 (Accuitomo), 0.801 (Orthophos), 0.762 (CS9300) and 0.779 (CS9600). Sensitivity, Specificity, PPV and NPV values were high for all four CBCT machines in detecting ECR (0.993, 0.977, 0.929 and 0.998, respectively). While sensitivity, specificity and NPV values were high (0.767, 0.792, 0.934), the PPV were less (0.467) when detecting AP. There was no significant difference between the different machines when detecting ECR. Within the limitations of this ex vivo study, no differences were found between the four CBCT units when detecting ECR and AP at early stages. All machines displayed better efficiency when detecting ECR than when detecting AP at early stages.en