Abstract
OBJECTIVES: To investigate the in vitro implant accuracy of robotic technology in mandibular all-on-4 phantoms under an improved process and positioning marker as well as the maximum lateral force exerted on the drill. METHODS: Four implants were placed in the mandibular phantom under the navigation of the task-autonomous robot using an improved process and positioning marker. Crestal, bottom, and angle deviations between the planned and placed implants were measured and the maximum lateral force experienced by different drills at different implant inclinations was recorded. RESULTS: A total of 52 implants were placed in 13 mandibular phantoms. The implant placement angle showed no significant effect on crestal, bottom, and angle deviation. A significant increasing trend in the maximum lateral force experienced by milling cutters and pilot drills was observed with increased implant placement angles. The maximum lateral force on milling cutters was significantly greater than the other drills in the same site (upright or tilted), and the maximum lateral force on pilot drills was significantly greater than that on twist drills in the same upright site (30° tilted site or 45° tilted site). CONCLUSIONS: The task-autonomous robot using an improved process and positioning marker achieved acceptable implantation accuracy in the mandibular all-on-4 phantom. Implant accuracy was not affected by the different implant angles. The entrance slope and the implant placement angle significantly affected the maximum lateral force on milling cutters and pilot drills. CLINICAL SIGNIFICANCE: This in vitro study provides an improved process, with acceptable implant accuracy, for the task-autonomous robot in the mandibular all-on-4 implant surgery.