Detection of Vertical Root Fractures by Different Resolutions of CBCT

The diagnosis of vertical root fracture(VRF) in endodontically treated teeth is a great clinical challenge due to lack of specific clinical and radiographic signs. Thus, the use of imaging methods, such as cone beam computed tomography (CBCT), is absolutely unavoidable. Restoring of endodontically treated teeth usually needs intracanal posts which can produce artifacts that may impair the quality of CBCT scans. This study aimed to compare the diagnostic accuracy of different resolutions of CBCT in detection of VRF in roots with casting post

Method:

In this study, 80 extracted human premolars were used. Routine endodontic procedure was followed and casting posts were subsequently prepared for all samples. The teeth were randomly divided into two groups. In the group with fracture, fracture lines were induced by Instron system, while the teeth in control group had no fracture. Then, all the teeth were scanned by CBCT with two voxel resolution protocol (0/15mm and 0/2mm). Three observers assessed the scans for presence of VRF on 5-point scale. Sensitivity, specificity, positive and negative predictive values were calculated and analyzed with Mann-Whitney test. P<0/05 regarded as significant.

Result:

Complete sensitivity for 0/15mm and 0/2mm resolution was 59/16±5/2 and 46/66±16/64, respectively. furthermore, Complete specificity for 0/15mm resolution was 56/16±15/21 and for 0/2mm was 61/66±8/77.There were no statistical difference between different resolutions in all diagnostic values including sensitivity, specificity, positive and negative predictive value(p>0/05).

Conclusion:

Diagnostic ability of CBCT in presence of casting post was not influenced by system resolution. According to ALARA (As low as reasonably achievable) principle, 0/2mm voxel resolution protocol is recommended in these cases.