Objective To compare the sensitivity of two clinically used cone beam computed tomography(CBCT) systems in detecting vertical root fracture(VRF) with or without canal filling of gutta-percha and evaluate the impacts of reconstruction plane(axial, sagittal or coronal) and root plane(cervical, middle or apical) on the sensitivity of diagnosis. Methods The 20 single constant mandibular premolar were researched, root in the specimens of mandibular first before grinding fang, alveolus socket according to different processing steps in turn has taken CBCT with small and large fov respectively four times, record the following 4 kinds of circumstances: no VRF+no root filling, no VRF+gutta-percha filling, VRF+no root filling, VRF+gutta-percha filling. The images were evaluated by two independent observers. Results 1)In the absence and presence of gutta-percha, CBCT with small fov was the most sensitive and accurate method in diagnosing VRF, compared with CBCT with large fov(P
