The effect of metal artifacts on the identification of vertical root fractures using different fields of view in cone-beam computed tomography

PURPOSE: The aim of this study was to investigate the effects of metal artifacts on the accurate diagnosis of root fractures using cone-beam computed tomography (CBCT) images with large and small/limited fields of view (FOVs). MATERIALS AND METHODS: Forty extracted molar and premolar teeth were collected. Access canals were made in all teeth using a rotary system. In half of the teeth, fractures were created by the application of mild pressure with a hammer. The teeth were then randomly put into a wax rim on an acryl base designed in the shape of a mandible. CBCT scans were obtained using a Newtom 5G system with FOVs of 18 cm×16 cm and 6 cm×6 cm. A metal pin was then placed into each tooth, and CBCT imaging was again performed using the same fields of view. All scans were evaluated by two oral and maxillofacial radiologists. The specificity, sensitivity, positive predictive value, negative predictive value, and likelihood ratios (positive and negative) were calculated. RESULTS: The maximum levels of sensitivity and specificity (100% and 100%, respectively) were observed in smallvolume CBCT scans of teeth without pins. The highest negative predictive value was found in the small-volume group without pins, whereas the positive predictive value was 100% in all groups except the large-volume group with pins. CONCLUSION: The specificity of CBCT decreased with the presence of a pin in the large-volume group, but not in the small-volume group.