Purpose: The purpose of the study was to investigate the accuracy of complete-arch intraoral scans for all-on-4 implant treatment under simulated intraoral variables.
Materials and methods: A maxillary model designed to receive 4 implants in the regions of first molars and canines was used. Intraoral digital scans were completed in a simulation device by simulating two2 different clinical conditions: normal intraoral variables (NIV) and limited intraoral variables (LIV). Digital scans were obtained using five 5 different IOSs: Trios 3 (TRI), Primescan (PR), iTero 2 (ITE), Medit i500 (MDT), and Aadva IOS 100P (AAD). Ten scans of each IOS were made and exported as STL files. Assessment of precision and trueness was conducted with Geomagic 3D analysis software. Each STL file was individually aligned with the reference scan and 3D differences were calculated using the root mean square (RMS) value. Data was statistically analyzed using 2-way ANOVA and Tukey HSD tests (α=.05).
Results: Regarding trueness, 2-way ANOVA and Tukey comparison tests revealed significant differences between different IOSs and intraoral variables. The AAD under LIV presented significantly higher RMS than TRI, PR, ITE, and MDT (p<.001). Regarding precision, the lowest mean RMS was obtained in the IOS group of PR under NIV. AAD presented significantly higher mean RMS in the groups of both NIV and LIV (p<.001). Limited intraoral variables significantly increased the RMS values for all IOSs tested (TRI, PR, ITE, MDT, and AAD).
Clinical Significance: Accuracy of complete arch all-on-4 implant scans were affected by different IOSs and intraoral variables. Simulating intraoral variables while testing IOSs might help to better validate their clinical use.