Title : The Influence of bone density on the implant accuracy of an autonomous dental implant robot
Abstract:
Statement of the Problem: The accuracy of implant placement is influenced by various factors, including preoperative imaging, implant design, surgical approach, and bone quality. Among these, bone density plays a particularly important role, yet its mechanism of impact on robotic implant placement remains unclear. With the growing application of autonomous dental implant robots, ensuring consistent accuracy across different bone densities has become a pressing clinical concern. This study aimed to evaluate the effect of bone density on implant accuracy using a standardized polyurethane foam block.
Materials and Methods: Polyurethane foam blocks of four densities (10, 20, 30, 40 PCF) were processed into standardized specimens (3cm × 2cm × 2cm) and fixed onto 3D-printed resin bases. Metallic replicas of Straumann BLT implants (4.1 × 10 mm) were inserted, six per block, for a total of 72 implants across four density groups. Preoperative planning was performed using CBCT and model scanning, followed by fully automated implantation with a dental implant robot. Postoperative CBCT scans were obtained, and deviations between planned and actual implant positions were analyzed through point cloud superimposition. Accuracy was evaluated by seven parameters, including entry, apical, and angular deviations.
Results and Discussions: entry, apical, and angular deviations decreased with increasing bone density, suggesting improved accuracy (P < 0.05). However, no significant difference was detected between certain groups (e.g., 20 vs. 30 PCF), indicating that the relationship is not strictly linear. Polyurethane models provided a homogeneous and controllable platform, effectively isolating bone density as an independent factor. Conclusion: Within the limitations of this study, the autonomous implant robot achieved high placement accuracy under all density conditions. Higher bone density was associated with reduced deviations, supporting its potential reliability in varied clinical scenarios.
