An Overview of Systematic Reviews and Meta-analyses Evaluating Different Impression Techniques for Implant-Supported Prostheses in Partially and Completely Edentulous Arches

Purpose: To summarize the evidence and determine the most effective impression technique for implant-supported prostheses in terms of accuracy, time efficiency, and patient preference in partially and completely edentulous arches.
Materials and Methods: The searches were performed independently up to April 30, 2021 by two review authors through the Cochrane Oral Health Review, MEDLINE/PubMed, LILACS, and Science Direct databases. Moreover, manual and gray literature searches were performed to identify further potential reviews. Only English language–based systematic reviews with and without meta-analyses evaluating the different dental implant impression techniques were included. The outcomes assessed were accuracy, time efficiency, and patient preference. The methodologic quality of the included reviews was investigated by using the R-AMSTAR tool, and the degree of overlap of primary studies was assessed by calculating the percentage of corrected covered area (CCA) as proposed by Pieper et al.⁶⁴
Results: The qualitative analysis included a total of 28 reviews, 8 of which included meta-analyses, published between 2008 and 2021, involving a total of 42 clinical trials and 203 laboratory studies. Digital vs conventional implant impression techniques were compared in 17 reviews, different digital impressions in 3 reviews, and different conventional impression techniques in the remaining reviews. Overall, the methodologic quality assessed by using the R-AMSTAR tool was moderate (mean: 26.7 ± 5.5) with slight overlap of primary studies (CCA; 5.23%).
Conclusion: Within an overall moderate methodologic quality, the digital implant impressions showed favorable outcomes in terms of accuracy, time efficiency, and patient preference in partially edentulous arches involving three or fewer implants. However, the accuracy of full-arch digital impressions involving multiple implants is not satisfactory and needs significant improvements. Hence, future studies following stringent guidelines and robust methodology are recommended to substantiate the findings of this overview and provide a high level of evidence.