Avaliação da acurácia da tomografia computadorizada de feixe cônico na detecção de fraturas radiculares verticais em dentes com núcleo metálico fundido

Abstract

The diagnosis of vertical root fractures is a challenge to dentists, and early detection will depend on the search of clinical and radiographic signs. Complementary exams are very important in this process, highlighting periapical radiography and cone beam computed tomography (CBCT). However, in endodontically treated and with metallic post teeth, the evaluation of tomographic image can be worse due to artifacts. The present study evaluated the accuracy of CBCT in detection of vertical root fractures in teeth with metallic cast post. Eighteen monorradicular human teeth were endodontically treated and prepared to metallic post. They were subjected to fractures in vitro, recovered with wax and inserted in dry human skulls. The sample was submitted twice (with and without metallic post) to periapical radiography and CBCT (2 voxels: 0,125mm e 0,25 mm).The images were analyzed by three radiologists and the results were submitted to statistical analysis. Sensibility, specificity, positive predictive and negative predictive values were calculated, beyond the areas under ROC curves (accuracy). The accuracy of the exams were compared by chi-squared test, showing no significant differences (p≥0,05). The comparisons between teeth with and without metallic posts in each exam, by Fischer exact test, revealed significant difference to CBCT voxel 0,125 and periapical radiography (p<0,05). The images of CBCT voxel 0,125 were more accurate in teeth without metallic post, although with no significance. It was concluded that periapical digital radiography, with variation of the horizontal angle, should be the first supplementary exam held for investigation of vertical root fractures. If this method is inconclusive, CBTC shows up an effective alternative in teeth without metallic post.