Digital scans versus conventional impressions in fixed prosthodontics: An overview of systematic reviews.

Abstract

Statement of problem: Several systematic reviews have compared the accuracy of conventional impression making and digital recording techniques, with sometimes different results. A systematic overview of these studies is lacking.

Purpose: The purpose of this overview of systematic reviews was to examine the accuracy of digital scans and conventional impressions for tooth- or implant-supported fixed restorations in partially and completely edentulous adult patients.

Material and methods: Four databases (Medline via PubMed, Scopus, Web of Science, and Google Scholar) were searched for systematic reviews according to preset eligibility criteria. Two calibrated evaluators screened and assessed the overall confidence of the included reviews using the A MeaSurement Tool to Assess systematic Reviews (AMSTAR) 2 tool. Several review characteristics were recorded, including accuracy in terms of trueness and/or precision. The Jadad et al¹ decision algorithm was used to select the best evidence, and a citation matrix was used to show overlaps in the studies.

Results: From the 307 studies that were retrieved, 28 systematic reviews were included in this overview. Among these, 12 performed meta-analyses, and 18 comprised both in vitro and in vivo primary studies. Generally, digital scanning and conventional impression techniques for crowns and fixed partial dentures, for implant-supported fixed restorations, and for both tooth- and implant-supported restorations showed no statistically significant differences in terms of accuracy (trueness and precision) and marginal and internal adaptation (P>.05). However, conventional impressions outperformed digital scans for complete-arch fixed dental prostheses in terms of accuracy. Regarding methodological quality, most systematic reviews (67.9%) received critically low overall confidence based on AMSTAR 2.

Conclusions: No significant differences were reported in terms of marginal and internal fit between prosthetic restorations constructed after digital scanning and conventional impression making. The opportunity exists to enhance the methodological quality of systematic reviews with regard to the accuracy of dental recordings.