Purpose: This study was performed to evaluate the dimensional accuracy of digital dental models constructed from conebeam computed tomographic (CBCT) scans of polyvinyl siloxane (PVS) impressions and cast scan models. Materials and Methods: A pair of PVS impressions was obtained from 20 subjects and scanned using CBCT (resolution, 0.1 mm). A cast scan model was constructed by scanning the gypsum model using a model scanner. After reconstruction of the digital models, the mesiodistal width of each tooth, intercanine width, and intermolar width were measured, and the Bolton ratios were calculated and compared. The 2 models were superimposed and the difference between the models was measured using 3dimensional analysis. results: The range of mean error between the cast scan model and the CBCT scan model was -0.15 mm to 0.13 mm in the mesiodistal width of the teeth and 0.03 mm to 0.42 mm in the width analysis. The differences in the Bolton ratios between the cast scan models and CBCT scan models were 0.87 (anterior ratio) and 0.72 (overall ratio), with no significant difference (P>0.05). The mean maxillary and mandibular difference when the cast scan model and the CBCT scan model were superimposed was 53 μm. conclusion: There was no statistically significant difference in most of the measurements. The maximum tooth size difference was 0.15 mm, and the average difference in model overlap was 53 μm. Digital models produced by scanning impressions at a high resolution using CBCT can be used in clinical practice. (Imaging Sci Dent 2019; 49: 257-63)