Force Feedback Implant Robot With Osseodensification Drilling for Transcrestal Sinus Floor Elevation: A Retrospective Case Series Study

Abstract

Objectives: This study evaluated the effectiveness of force-feedback–based autonomous dental implant robotic systems combined with osseodensification (OD) for transcrestal sinus floor elevation (TSFE), to understand patterns of force-feedback curves, visualize the TSFE process through mechanical vision, and offer new perspectives on surgical strategies. Materials and Methods: The included patients required simultaneous implant placement and TSFE. Preoperative planning was performed, and during surgery, using an OD drill, the robotic arm was guided to create a microfracture on the sinus floor, elevate the sinus membrane, and place the implant, all under the surgeon's supervision. Postoperative cone-beam computed tomography evaluated sinus lift and implant accuracy. The visual analog scale was used to measure patient-reported outcomes. Mechanical curves were plotted using extracted force-feedback values. Data are reported as mean ± standard deviation and Pearson's correlation for linear relationships (p < 0.05 was statistically significant). Results: Overall, 17 patients (18 implants) were included, with a 94.4% implant retention rate at 6 months postoperatively. The Fz force-feedback curve showed a critical peak followed by a sharp drop at the sinus-floor breakthrough point and a gradual rise followed by a steep decrease as the bone graft entered the sinus cavity. Cortical bone density at the sinus floor positively correlated with force feedback (p < 0.05). Conclusions: Force-feedback–based implant robotics combined with OD is an innovative and reliable approach for TSFE. Integrating mechanical vision with force-feedback curves allows for precise identification of microfracture points and safe sinus membrane elevation, overcoming the limitations of traditional blind techniques and enhancing procedural safety and predictability. Trial Registration: Chinese Clinical Trial Registry: ChiCTR2300072248.