The Effect of the Scanning Number on Accuracy of Digital Impression

Background: Intraoral digital scanning could offer a win-win clinical pathway for both doctor and patient, but many factors can affect its accuracy. This study was designed to investigate the effect of the scanning number on the precision of digital impression in different gypsum models. Materials and methods: 30 standard gypsum models were divided into group A, B, C, D and E. Each group was scanned with 400 and 1000 pictures by Trios. Then Using the three-dimensional preview function to compare the fitted images and to measure the distance between markers: the buccal-lingual thickness of maxillary central incisors, the length from the medial to the distal of buccal cusps of maxillary second molars, the crown width of mandibular central incisors, the buccal-lingual thickness of maxillary central incisors requiring a veneer, and the buccal-lingual width of the inlay of the mandibular first molar. Results: The scanning time of 1000 scanning number groups were significantly prolonged and the efficiency of 3D reconstruction was significantly reduced. But obvious image stitching distortion could be observed in these groups compared with 400 scanning number groups. Whats more, the compare of measured values in each 400 and 1000 scanning number group was all statistically significant. Conclusion: The data splicing caused by the excessive scanning number may influence the digital impression accuracy. Trios scans 400 pictures was with higher scanning accuracy than scanning 1000 pictures.