The effect of thickness, arch type, and storage duration on the dimensional stability and seating accuracy of 3d-printed implant surgical guides

Abstract

This study investigated the effects of guide thickness, arch span, and storage duration on the dimensional stability and seating accuracy of 3D-printed implant surgical guides. Forty-eight surgical guides were fabricated using stereolithography (SLA) in partial-arch (PA) and full-arch (FA) surgical template designs across three thickness levels (2, 3, and 4 mm). All designs were fabricated for single-missing-tooth cases. The guides were stored for up to 14 days and evaluated at five time points (0, 1, 3, 7, and 14 days). Dimensional changes were quantified using root mean square error (RMSE) and visualized through colormap analysis, and seating accuracy was assessed by model-based mounting analysis. Most dimensional deformation occurred within the first 24 hours, with stabilization thereafter. Among PA guides, the 2-mm-thick group exhibited a pronounced increase in deformation at day 7 (RMSE: 200.14 ± 37.52 µm), whereas 3-mm and 4-mm PA guides remained dimensionally stable throughout the observation period (4-mm at day 14: 45.90 ± 3.73 µm). FA guides showed more consistent RMSE values across thicknesses and time points than PA guides (4-mm at day 14: 65.16 ± 0.47 µm) and maintained consistent seating accuracy throughout the study. Three-way ANOVA revealed significant main effects and interactions among thickness, arch span, and storage duration with respect to both deformation and seating accuracy (p < 0.001). Based on these findings, a minimum guide thickness of more than 2 mm is recommended and at least 24 h of post-curing stabilization should be observed before clinical use.