Effects of exposure time and voxel size on measured alveolar bone thickness in cone-beam computed tomography: An

Purpose: This study assessed the effects of cone-beam computed tomography (CBCT) voxel size and exposure settings on the accuracy of alveolar bone thickness (BT) measurements. Materials and Methods: Seven pig mandibles were scanned using 6 CBCT settings: 200, 400, and 600 µm voxels, each with an ultra-low dose (ULD) and a standard dose (SD) setting. BT was measured at 3 locations on 1 anterior and 1 posterior tooth. These teeth were then scanned using micro-computed tomography (micro-CT), and BT was measured at the same locations. The intraclass correlation coefficient (ICC) and paired Results: The lowest discrepancy between micro-CT and CBCT was observed with the 600 µm ULD (0.29±0.39 mm), followed by the 200 µm SD (0.41±0.72 mm). When BT was less than 2 mm, the lowest discrepancy occurred with the 200 µm SD (0.29±0.33 mm), followed by the 600 µm ULD (0.32±0.25 mm). The ICC between CBCT and micro-CT decreased as BT decreased. RMANOVA indicated no significant effect of CBCT settings on measurement accuracy. Conclusion: BT measured with the 600 µm ULD was comparable to that obtained with the 200 µm SD. The discrepancy between CBCT and micro-CT was notable, especially when BT was less than 2 mm.