Accuracy and Clinical Performance of Intraoral Scanners Compared to Conventional and Extraoral Impressions: An...

Digital impression technologies have transformed modern dental workflows, with intraoral scanners (IOS) emerging as a prominent alternative to conventional elastomeric impressions and extraoral scanning systems. This umbrella review aims to comprehensively synthesize evidence from systematic reviews, meta-analyses, and umbrella reviews evaluating the accuracy, efficiency, and clinical applicability of IOS across various prosthodontic, implant, and orthodontic applications. A total of 10 reviews published between 2020 and 2024 were included, encompassing over 30 IOS models and a wide spectrum of clinical settings. Trueness and precision were the most frequently evaluated outcomes, with TRIOS 3 (3Shape, Copenhagen, Denmark) and Primescan (Dentsply Sirona, Charlotte, NC, USA) consistently ranking highest in complete-arch accuracy. Compared to traditional impressions, IOS generally reduced procedural time and enhanced patient comfort, although accuracy in partially edentulous and edentulous arches remained a limiting factor. Meta-analytical findings supported the superior performance of certain IOS platforms over others and affirmed the time-saving benefits of digital scanning. However, most reviews relied heavily on in-vitro studies, and few conducted robust risk of bias assessments or used the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach to assessing certainty of evidence. Assessment of Multiple Systematic Reviews-2 (AMSTAR-2) analysis revealed only two reviews met high-quality methodological standards, while others showed moderate to critically low ratings. The findings underscore the clinical advantages of IOS while highlighting the need for standardized protocols and higher-quality evidence in complex restorative scenarios.