Conventional versus Digital Dental Impression Techniques: What Is the Future? An Umbrella Review

A prosthetic rehabilitation, whether supported by implants, teeth, or mucous membranes, must be functionally and aesthetically adequate, so it is essential that the oral structures are reproduced as accurately as possible. The purpose of this overview is to evaluate the accuracy, time of digital impressions, and patient preference compared to those of conventional high-precision in vivo impressions. This umbrella review was developed following the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses) statement and was registered in the PROSPERO systematic review registry. The search method and study selection were based on the PEO (Population–Exposure–Outcome) model, a modified version of the PICO model. Systematic reviews regarding the dental impression technique made using an intraoral scanner versus the analog impression technique made with high-precision impression materials were searched electronically up to 1 February 2023 among articles published in English, through numerous registries and databases, such as PROSPERO e, Scopus, MEDLINE/ PubMed, BioMed Central, and Cochrane Library. The records screened totaled 2942, but only 23 systematic reviews were included in this umbrella review. The Assessing the Methodological Quality of Systematic Reviews (AMSTAR) 2 tool was used to evaluate the quality assessment of the systematic reviews included in this umbrella review. Accuracy, time, and patient preference for digital impressions were compared with those of high-precision conventional impressions. A total of 23 systematic reviews were included in this umbrella review. From the analysis of this umbrella review, the data on the accuracy between the two methods of taking the impression are conflicting, especially as regards full-arch rehabilitations. However, the digital impression seems to be preferred over the analog one as regards time and patient preference. However, there is limited high-quality evidence available for studying conventional and digital implant impressions. The results obtained are limited to the type of review performed, and the type of studies included was limited by the settings and study designs. Furthermore, another important limitation highlighted was that the digital scanners analyzed in the various studies are not the same, and the number of missing teeth or implants inserted is not the same. More in vivo clinical studies and RCTs are needed to increase the level of evidence for impression procedures.