Comparing trueness of implant positioning in a single implant 3D model obtained by different scanning techniques

Aim: To compare the trueness of single-implant position in 3D digital models obtained using an intraoral scanner (IOS) and a laboratory scanner, using an industrial scanner as the reference standard.Settings and Design: Comparative in vivo cross-sectional observational studyMaterials and Methods: Twenty patients requiring single-tooth implant restorations were included. For each case, three STL files were generated: from a gypsum model scanned with an industrial scanner (control), a laboratory scanner, and an Intra-oral scan with scan body. Deviations in implant positioning along X (buccolingual), Y (mesiodistal), Z (vertical), and combined X+Y (horizontal) axes were analyzed using Geomagic Control X software.Statistical Analysis: Data were analyzed using SPSS v21. Descriptive statistics and Wilcoxon signed – rank test were applied. Significance was set at p < 0.05.Results: Mean deviations for the Laboratory Scanner along the X, Y, Z, and horizontal (X+Y) axes ranged from –6.564 mm to 2.197 mm, while deviations for the intraoral scanner (IOS) ranged from –6.455 mm to 2.953 mm. Differences between the Laboratory Scanner and IOS were not statistically significant along the X, Y, and X+Y axes (p = 0.940, p = 0.057, and p = 0.823, respectively). In contrast, along the Z-axis, the Laboratory Scanner (–0.015 mm, SD = 0.056 mm) demonstrated significantly greater trueness compared to IOS (0.051 mm, SD = 0.097 mm) (p = 0.047).Conclusion: Within study limitations, both scanners produced deviations well below the clinically acceptable threshold of 120–150 µm. Laboratory Scanner demonstrated superior trueness in the vertical axis, while IOS, though efficient, showed higher variability and should be used cautiously in precision-sensitive cases.