Comparison between hybrid CBCT and CBCT in detection of vertical root fracture

Cone beam computerized tomography (CBCT) has been wildly used in many fields of dentistry, especially to investigate the vertical root fracture (VRF). CBCT systems were consisted of various field of view (FOV). As for high cost and large machine size, newly designed of CBCT systems started to develop by combining digital panoramic radiographs with a relatively small-to-medium FOV CBCT system. These new model of CBCT systems was called hybrid CBCT. The aims of this study is to compare the difference in detection of VRF by a hybrid CBCT and a CBCT. For this, forty permanent mandibular premolar teeth were endodontically prepared and individually inserted dry human mandible. All teeth were scanned with two CBCT systems by using various scanning protocols. Three observers were randomly evaluated all radiographic images. As a result, CBCT and hybrid CBCT have similar abilities in detecting VRF, however, CBCT system show a slightly higher performance. Moreover, with smaller FOV and voxel size, better VRF detection can be achieved. Furthermore, presentation of root canal filling material can reduce diagnostic ability of the VRF for overall CBCT systems.  In conclusion, detection of VRF with hybrid CBCT is not significantly different from that in CBCT system. However, further researches are required.