Accuracy of digital implant impressions in clinical studies: A systematic review

Objectives The use of intraoral scanners (IOSs) for digital implant impressions in daily clinical practice is increasing. However, no structured literature review on the accuracy of digital implant impressions in clinical studies has been described to date. Therefore, this systematic review aimed to answer the PICO question: Which accuracy is described for digital implant impressions in clinical studies? Material and Methods An electronic database search was conducted in December 2021 using MeSH terms and free-text search. English-language studies addressing the accuracy of digital implant impressions in clinical studies involving at least 10 patients were included. All clinical indications were considered. Results Eight publications between 2014 and 2021 matched the review criteria. However, the study designs showed considerable differences. The number of implants within the studies ranged from 1 to 6, and the number of patients ranged from 10 to 39. The oldest study (2014) revealed the highest deviation for linear distances at 1000 +/- 650 mu m, whereas the other studies reported data in the range of 360 +/- 46 mu m to 40 +/- 20 mu m. In one study, no numerical data were reported and all studies compared digital and conventional implant impressions. Conclusions The number of clinical studies on the accuracy of digital implant impressions is low. Thus, the impact of different factors, such as the scanpath or scanbody, could not be identified. However, the accuracy of recent IOSs for digital implant impressions in patients was shown to be clinically acceptable. Nevertheless, the transfer error still needs to be considered when fabricating implant-supported restorations.