Accuracy of robotic-assisted implant placement in second molars combined with step drills and manual-automatic switching function: a retrospective study

Nowadays, robotic computer-assisted implant surgery (r-CAIS) has drawn great attention in implant dentistry; however, the clinical application of r-CAIS for limited operating space such as the second molar region, has not been demonstrated. Thus, this study aimed to evaluate the accuracy of r-CAIS in second molars in combination with step drills and manual-automatic mode switching function. Patients who lost second molars and underwent r-CAIS were enrolled in this study. The positioning marker was installed preoperatively, and a cone-beam computed tomography (CBCT) scan was subsequently performed. The CBCT data were subsequently transferred into the robotic software, and a preoperative surgical plan was generated. After marker registration and calibration, the implant osteotomy was completed by the robotic arm under the control of the surgeons. Owing to the limited operating space in the second molar region, the operation mode of r-CAIS was switched between manual and automatic modes, and step drills were used in combination. Patients underwent postoperative CBCT, and the accuracy was evaluated using the CBCT data between the planned and placed implants. A total of 16 patients were enrolled in this study, and no adverse events occurred during or after surgery. The mean global coronal, apical and angular deviations were 0.43 ± 0.10 mm (95%CI: 0.38 to 0.49 mm), 0.44 ± 0.10 mm (95%CI: 0.38 to 0.49 mm), and 0.88 ± 0.53°(0.60 to 1.16°), respectively. r-CAIS can achieve high accuracy in the second molar region when combined with step drills and manual-automatic mode switching function. Further prospective studies are needed to validate the effects.