Application of a semi-active robotic system for implant placement in atrophic posterior maxilla: A retrospective case series

Objective: The study aimed to evaluate the accuracy and safety of a semi-active robotic system for implant placement in atrophic posterior maxilla. Methods: Patients underwent robot-assisted implant placement in atrophic posterior maxilla were identified and included. Cone-beam computed tomography (CBCT) was performed before surgery. The virtual implant position and drilling sequences were planned in the robotic planning system. Patients with positioning marker took an intraoral scan. The preoperative CBCT and the intraoral scan were superimposed in the robotic software. After registration, the implant bed was prepared utilizing the robotic arm with 1 mm safety margin below the maxillary sinus floor. The transcrestal sinus floor elevation (TSFE) was performed by the dentist, followed by the implant placement with the robotic arm. A postoperative CBCT was taken and superimposed with the preoperative one to calculate the accuracy of implant placement. Complications and adverse events were recorded. Deviations between the implant platform and apex levels were analyzed using the paired t-test. P < 0.05 was considered statistically significant. Results: Twenty-seven implants of 20 patients were included. No intraoperative and postoperative complications were reported. The global, lateral and vertical platform deviations were 0.73 ± 0.27 mm, 0.35 ± 0.23 mm and 0.35 ± 0.57 mm, respectively. The global, lateral and vertical apex deviations were 0.77 ± 0.23 mm, 0.41 ± 0.20 mm and 0.34 ± 0.57 mm, respectively. There were significant differences between the global, lateral and vertical deviations between the implant platform and apex levels (P < 0.05, respectively). The angular deviation was 1.58 ± 0.76°. Conclusions: High accuracy and safety for implant placement in atrophic posterior maxilla could be achieved using a semi-active robotic system, with the TSFE procedure performed by the dentist. Clinical significance: This study provides significant evidence to support the application of semi-active robotic systems for implant placement in atrophic posterior maxilla.