Enhancing intraoral scanner accuracy using scan aid for multiple implants in the edentulous arch: An in vivo study

Objectives: Intraoral scans of multiple implants in the edentulous arch are challenged by the absence of a distinct surface morphology between scan bodies. A scan aid was applied in such situation and evaluated for intraoral scanning accuracy in vivo. Materials and Methods: 87 implants in 22 patients were scanned with scan aid (SA) and without scan aid (NO) using two different intraoral scanners (CS3600 [CS] and TRIOS3 [TR]). Master casts were digitized by a laboratory scanner. Virtual models were superimposed using an inspection software and Linear deviation and precision were measured. Statistical analysis was performed using linear mixed models (alpha =.05). Results: Total mean linear deviation within the CS group was 189 mu m without scan aid and 135 mu m when using the scan aid. The TR group's total mean deviation was 165 mu m with and without a scan aid. Significant improvement with scan aid was observed for the CS group (p =.001), and no difference was found in the TR group. 96% of scan bodies were successfully scanned in the TR-SA group compared to 86% for the TR-NO group, 83% for the CS-SA, and 70% for the CS-NO group, respectively. Conclusions: The evaluated scan aid improved linear deviation compared to unsplinted scans for the CS group but not for the TR group. These differences could originate from different scanning technologies used, active triangulation (CS) and confocal microscopy (TR). The scan aid improved the ability to recognize scan bodies successfully with both systems, which could have a favorable clinical impact overall.