The accuracy of different dental impression techniques for implant‐supported dental prostheses: A systematic review and meta‐analysis

Abstract

Aim: This systematic review and meta-analysis were conducted to assess and compare the accuracy of conventional and digital implant impressions. The review was registered on the PROSPERO register (registration number: CRD42016050730). Material and Methods:A systematic literature search was conducted adhering to PRISMA guidelines to identify studies on implant impressions published between 2012 and 2017. Experimental and clinical studies at all levels of evidence published in peer-reviewed journals were included, excluding expert opinions. Data extraction was performed along defined parameters for studied specimens, digital and conventional impression specifications and outcome assessment. Results: Seventy-nine studies were included for the systematic review, thereof 77 experimental studies, one RCT and one retrospective study. The study setting was in vitro for most of the included studies (75 studies) and in vivo for four studies. Accuracy of conventional impressions was examined in 59 studies, whereas digital impressions were examined in 11 studies. Nine studies compared the accuracy of conventional and digital implant impressions. Reported measurements for the accuracy include the following: (a) linear and angular deviations between reference models and test models fabricated with each impression technique; (b) threedimensional deviations between impression posts and scan bodies respectively; and (c) fit of implant-supported frameworks, assessed by measuring marginal discrepancy along implant abutments.) Meta-analysis was performed of 62 studies. The results of conventional and digital implant impressions exhibited high values for heterogeneity. Conclusions: The available data for accuracy of digital and conventional implant impressions have a low evidence level and do not include sufficient data on in vivo application to derive clinical recommendations. K E Y W O R D S computer-aided design, digital implant impressions, implant impressions, intraoral scanningThis is an open access article under the terms of the Creative Commons Attribution-NonCommercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes.

The effect of scanning the palate and scan body position on the accuracy of complete‐arch implant scans

“…Digital workflows play an important role in implant dentistry through acquiring implant positions and displaying them in a virtual model . Scan bodies have been developed to take digital implant scans by creating an accessible surface for optical acquisition and are readily detectable and can be matched with the corresponding digital implant library by the software .…”

Impact of Different Scan Bodies and Scan Strategies on the Accuracy of Digital Implant Impressions Assessed with an Intraoral Scanner: An In Vitro Study

“…In dentistry, implant‐supported prostheses can be produced according to a conventional or digital workflow. In each case, impression making is the first step prior to the subsequent fabrication of a dental prosthesis . Both processes have specific advantages and disadvantages.…”

“…In this context, the open tray technique, has been shown to be superior to the closed tray technique . Furthermore, the kind of impression material, implant level, implant angulation, and transfer copings influence the accuracy of the conventional impression . One study demonstrated no significant difference in the marginal discrepancy of conventional impressions depending on the implant or abutment level .…”

Annual review of selected scientific literature: A report of the Committee on Scientific Investigation of the American Academy of Restorative Dentistry

“…Flugge et al 210 reported on a meta-analysis of the literature addressing the accuracy of different impression techniques for implant-supported dental prostheses. Overall, 59 studies evaluated conventional impressions, 11 digital scans, and 9 compared both techniques.…”