Implant‑position reproducibility of wired and wireless intraoral scanners and the effects of Wi‑Fi distance and upload speed: an in vitro study.

backgroundThe impact of wireless communication on intraoral scanning reproducibility remains unclear. This in‑vitro study aimed to compare the implant‑position reproducibility of wireless (Wi‑Fi) and wired intraoral scanners using a mandibular edentulous model with six implants and to evaluate how Wi‑Fi distance and upload speed affect reproducibility in wireless intraoral scanners.

methodsAn edentulous mandibular model with six implants was scanned as the reference dataset using a high-accuracy laboratory scanner. Optical impressions were obtained using three wireless intraoral scanners (designated as Primescan 2, SIRIOS, and TRIOS 5) and one wired intraoral scanner (Primescan). For wireless devices, the scanner–router distance was set at 0.5, 2.0, and 5.0 m. The wired Primescan served as the control. Five scans per condition were acquired and analyzed. Upload speed was measured immediately before scanning at each distance tested. The reference and intraoral scanner datasets were superimposed for three-dimensional analysis. Reproducibility was expressed as the concordance rate, i.e., the percentage of surface area within ± 50 μm of the reference dataset. The association between upload speed and reproducibility was examined. The median and interquartile range were calculated for concordance rates; group differences were tested using the Kruskal–Wallis test with Steel–Dwass post‑hoc comparisons, and within‑device associations between upload speed and concordance were examined by linear regression (two‑sided α = 0.05).

resultsPrimescan 2 showed stable concordance across distances (> 78.8%; p > 0.05) and exceeded Primescan at all distances (63.5%; p < 0.05). SIRIOS (64.6→50.4%) and TRIOS 5 (61.6→29.5%) showed decline with distance; at 0.5 m, both were comparable to Primescan, whereas at 5.0 m, TRIOS 5 < SIRIOS (p < 0.05). Across devices at identical distances, Primescan 2 > SIRIOS/TRIOS 5 (p < 0.05). Upload speed correlated with concordance for SIRIOS (β = 0.0369, R² = 0.725, p < 0.001) and TRIOS 5 (β = 0.0707, R² = 0.567, p = 0.001), but not for Primescan 2 (β = 0.0177, R² = 0.077, p = 0.318).

conclusionsPrimescan 2 showed higher implant‑position reproducibility than wired Primescan at all tested distances and was insensitive to Wi‑Fi distance and upload speed. SIRIOS and TRIOS 5 matched the wired comparator at 0.5 m but showed decline at 2.0–5.0 m; upload speed correlated positively with reproducibility for SIRIOS and TRIOS 5, but not for Primescan 2, indicating dependence on device architecture and Wi‑Fi link quality.