Accuracy of digital versus conventional implant impressions in partially dentate patients: A systematic review and meta-analysis

To compare the accuracy of digital and conventional impression techniques in partially dentate patients undergoing implant-supported prosthodontic treatment. The primary focus was three-dimensional accuracy, including angular and linear deviations, inter-implant distances, and scan-body misfit. Data were extracted from seven clinical studies involving 151 partially dentate patients. Only three studies contributed data to the angular displacement meta-analysis, and four studies to the deviation analysis. The studies included randomised controlled trials and non-randomised clinical investigations comparing intraoral scanner (IOS)-based digital impressions with conventional impressions using polyvinyl siloxane or polyether materials. A systematic search was conducted in March 2025 across five databases: PubMed, EMBASE, Web of Science, CINAHL, and the Cochrane Library. PRISMA 2020 guidelines conducted the review and were prospectively registered with PROSPERO (CRD420251006999) and the International Platform of Registered Systematic Review and Meta-analysis Protocols (INPLASY202530032). Eligible studies were those that clinically assessed impression accuracy in partially dentate implant patients using either digital or conventional methods. Studies were included if they reported quantitative measures of impression accuracy. In vitro studies, non-implant restorative comparisons, and fully edentulous patient cohorts were excluded. Digital impressions demonstrated significantly lower deviation than conventional impressions, indicating superior spatial accuracy in certain clinical settings. However, no significant difference was observed in angular displacement. Considerable heterogeneity (I² = 80-97%) across studies limits the certainty of pooled outcomes. Digital impressions are a clinically acceptable alternative for short-span implant restorations in partially dentate patients, though caution is warranted in cases involving long-span or angulated implants. Further high-quality clinical trials with standardised protocols are needed to support broader clinical adoption. Digital impressions are a clinically acceptable alternative to conventional methods in partially dentate patients. Nevertheless, clinicians should exercise caution in long-span restorations or angulated implants until further high-quality studies with standardised protocols and long-term data are available.