Impact of bone surface inclination on the precision of static fully guided implant surgery: A quantitative analysis.

Background/purpose: Although static fully guided systems improve the accuracy of implant placement, most studies have focused on flat bone surfaces, with limited exploration of the effects of sloped bone surface. In this study, we aimed to evaluate the effects of bone surface inclination on the accuracy of static fully guided implant surgery. Materials and methods: Three 3D-printed maxillary models with a missing upper right lateral incisor were fabricated and each accommodated artificial bone blocks (Sawbones®). Bone blocks were grouped according to the buccal surface inclination (0°, 30°, and 60°; n = 10 per group). A static fully guided surgical system was designed using cone beam computed tomography and model scan data, and implants (Nobel Parallel Conical Connection RP, 4.3 mm × 13 mm) were placed by a single operator. The post-placement accuracy was assessed by mapping the scanned implant data with the surgical plan in Geomagic Control X. Deviations in the entry point, apex, vertical and horizontal positions, as well as angular deviation, were measured. Statistical analysis was performed using one-way ANOVA with Bonferroni post hoc test ( Results: Significant differences were observed in the entry point, apex, angular, and vertical deviations across the inclination groups; however, no significant difference was found in the horizontal deviations. Of the 30 implants, 23 deviated toward the buccal side. Conclusion: Bone surface inclination significantly affects the accuracy of static, fully guided implant surgery. Preoperative planning and guide design should consider these effects in order to optimize implant placement outcomes.