Comparing the accuracy of ten intraoral scanners in a chairside reverse scan body workflow for a complete arch implant-supported prosthesis: an in vitro study

Description :

The accuracy of IOS plays a critical role in modern prosthodontics, particularly for full-arch ISP, where precise digital impressions can significantly impact clinical outcomes. Even though a similar study is present in the literature, it only compared the accuracy of 4 IOS using the reverse technique (37). However, this study will evaluate the accuracy of ten different IOS. In order to do so, a previous all-on-6 case will randomly be selected for rehabilitation using six Straumann Bone Level Implants (BLT/BLX) with screw-retained abutments (SRA). A complete arch IP will be designed using exocad DentalCAD and fabricated using a 5-axis milling machine with a PMMA multilayer resin block. The IP will then be cemented to variobase abutments with Multilink Hybrid Abutment Cement following Straumann's guidelines, which will make the IP ready for extraoral scanning. Scanning is a digital alternative to conventional impressions, and it involves capturing detailed 3D images of dental structures. In this study, ten IOS and one desktop scanner (DS) will be used under consistent conditions. Unlike conventional impressions, which use physical materials to create a mold, scanning provides immediate, precise digital files that will later allow the digital design and fabrication of the IP. Following the strategy by Papaspyridakos et al. (36), the scans will ensure no voids at the RSBs, and STL files will be superimposed with the reference file (given by the DS) to assess trueness, precision, and discrepancies using metrology software. The time taken for each scan is also recorded to identify the fastest IOS.