Digital vs Conventional Implant Impressions: A Systematic Review and Meta‐Analysis

Abstract

Purpose: To systematically review in vitro and clinical studies comparing quantitatively the 3D accuracy (global implant deviations) of digital vs conventional implant impressions for partially and completely edentulous patients. Materials and Methods: Electronic and manual searches were conducted to identify in vitro and clinical studies, reporting on the 3D accuracy between digital and conventional implant impressions. Secondary outcomes were the effect of implant angulation, type of conventional impression technique, and type of intraoral scanner on the accuracy of implant impressions. Results: The inclusion criteria were met by 9 in vitro studies and 1 clinical study reporting on completely edentulous impressions, while 6 in vitro and 2 clinical studies reported on partially edentulous impressions. Quantitative meta-analysis was performed for 5 completely edentulous and 6 partially edentulous studies. The studies exhibited high values for heterogeneity. A random effects model was conducted to estimate the effect size. Based on 5 in vitro studies on completely edentulous impressions, the mean 3D implant deviation between conventional and digital impressions was 8.20 µm (95% CI: −53.56, 37.15) and the digital impressions had nominally less deviation (p = 0.72). Based on 1 clinical and 5 in vitro studies on partially edentulous impressions, the mean 3D implant deviation between conventional and digital impressions was 52.31 µm (95% CI: 6.30, 98.33) and the conventional impressions had nominally less deviation (p = 0.03). Five in vitro and 2 clinical studies were not included in the quantitative analysis due to heterogeneity in the methodology. Implant angulation affected the accuracy in favor of the partially edentulous conventional impressions whereas the effect of different scanners was not statistically significant on the completely edentulous impressions (p = 0.82). Conclusions: Digital scans appear to have comparable 3D accuracy with conventional implant impressions based mainly on in vitro studies. However, clinical trials are recommended to investigate the clinical accuracy of digital scans and digitally fabricated interim or prototype prostheses, before digital implant scans can be recommended for routine clinical use.

Three‐Dimensional Accuracy of Conventional Versus Digital Complete Arch Implant Impressions

“…Besides, scanning the multiple scan bodies can be quite challenging for the IOS to distinguish these parts from each other and create an image in the correct position within the arch 11 . Although there have been many studies regarding the accuracy of digital impressions on complete arch implant cases, 12–18 in a current systematic review published by Papaspyridakos et al 19 only one study comparing both digital and conventional impression techniques in a jaw containing more than 6 implants has been detected. Tan et al 20 evaluated the accuracy of digital and conventional impression techniques on 8 parallel implants placed in the maxilla.…”

The Influence of Hard- and Software Improvement of Intraoral Scanners on the Implant Transfer Accuracy from 2012 to 2021: An In Vitro Study

“…With regard to implant impressions, the results of a previous clinical study even showed similar results between conventional and digital impression methods when taking impressions of maxillary situations or partially edentulous jaw sections [4]. Comparable results were also obtained in other studies [17,18].…”

“…However, this may be due to a different evaluation method of the linear distances. Lower deviations were found in investigations by Menini et al [46], Papaspyridakos et al [18], and Rutkunas et al [47]. It is hypothesized that the small distances between the implants are decisive factors which typically cause only small deviations in the transfer accuracy.…”

A comparative clinical study on the transfer accuracy of conventional and digital implant impressions using a new reference key‐based method

“…If this "matching process" is flawed, a three‐dimensional shift may also occur, resulting in transfer errors of the implant position to the model (Güth et al., 2016; Keul & Güth, 2020; Kuhr et al., 2016; Park et al, 2015; Schmidt, Klussmann, et al., 2020). As overall clinical data are sparse, there is an urgent need for valid clinical data on conventional and digital implant impressions as described by Papaspyridakos et al (Papaspyridakos et al., 2020), and to the best of our knowledge, there is no clinical study describing implant impressions using reference keys.…”