Accuracy of intraoral scans: An in vivo study of different scanning devices.

STATEMENT OF PROBLEM:The accuracy of intraoral scanners is a prerequisite for the fabrication of dental restorations in computer-aided design and computer-aided manufacturing (CAD-CAM) dentistry. While the precision of intraoral scanners has been investigated in vitro, clinical data on the accuracy of intraoral scanning (IOS) are limited. PURPOSE:The purpose of this clinical study was to determine the accuracy of intraoral scanning with different devices compared with extraoral scanning. MATERIAL AND METHODS:An experimental appliance was fabricated for 11 participants and then scanned intraorally and extraorally with 3 different intraoral scanners and a reference scanner. Intraoral and extraoral scans were subdivided into complete-arch and short-span scans and compared with the reference scan to assess trueness. Repeated scans in each group were assessed for precision. RESULTS:Precision and trueness were higher for extraoral scans compared with intraoral scans, except for complete-arch scans with 1 intraoral scanner. The median precision of short-span scans was higher (extraoral: 22 to 29 μm, intraoral: 23 to 43 μm) compared with complete-arch scans (extraoral: 81 to 165 μm, intraoral: 80 to 198 μm). The median trueness of short-span scans (extraoral: 28 to 40 μm, intraoral: 38 to 47 μm) was higher than that of complete-arch scans (extraoral: 118 to 581 μm, intraoral: 147 to 433 μm) for intraoral and extraoral scanning. CONCLUSIONS:Intraoral conditions negatively influenced the accuracy of the scanning devices, which was also reduced for the complete-arch scans.