Evaluation of Digital Imaging Accuracy Among Three Intraoral Scanners for Full-Arch Implant Rehabilitation

<b>Background/Objectives:</b> Accurate full-arch implant impressions are essential for predictable digital prosthodontics, yet the performance of different intraoral scanners (IOSs) remains variable. This in vitro study compared the trueness and precision of three widely used IOSs-Sirona Primescan, 3Shape TRIOS Core, and Medit i700-in a standardized full-arch implant model. <b>Methods:</b> A maxillary model with six multi-unit implants was digitized using a high-accuracy laboratory scanner to obtain the reference dataset. Each IOS was used to perform ten scans, exported as unmodified STL files. Accuracy was evaluated in Geomagic Control X through a two-step alignment and a peri-implant region-of-interest deviation analysis. Trueness (mean absolute surface deviation, µm) and precision (SD) were compared using one-way ANOVA with Tukey's test (α = 0.05). <b>Results:</b> Primescan and TRIOS Core showed comparable trueness (202.76 ± 13.89 µm and 204.21 ± 2.61 µm, respectively), while Medit i700 demonstrated significantly higher deviations (221.05 ± 6.28 µm) (<i>p</i> < 0.05). TRIOS Core exhibited the highest reproducibility across repeated scans. <b>Conclusions:</b> The three scanners demonstrated measurable accuracy differences under standardized conditions. Primescan and TRIOS Core performed similarly in trueness, with TRIOS Core achieving superior precision. Medit i700 showed higher deviation values but remained consistent in its performance. These findings highlight measurable differences in accuracy and reproducibility among intraoral scanners under standardized laboratory conditions and may assist clinicians in selecting appropriate devices for full-arch digital implant workflows; however, clinical validation is required to confirm their performance in vivo.