2022 Volume 24 Issue 4 Pages 226-233
Dental implant treatment is an excellent treatment method that places little burden on healthy teeth and offers many advantages in terms of masticatory function and esthetics. However, it requires advanced surgical skills, and medical accidents continue to occur. In particular, when the hardness of the cortical bone just below the maxillary sinus is high, there is a risk of damage to the maxillary sinus membrane after penetration of the cortical bone, even when variously devised drills and instruments are used. Methods to detect penetration and stop drilling based on bone density estimated by a robot have been proposed. However, they require elaborate modeling of the bone. Another method has been proposed to capture changes in bone quality by focusing on fluctuations in cutting torque. However, it is greatly affected by the direction of cutting and other factors. Therefore, this paper proposes a method to realize more robust penetration detection and stop control by superimposing vibrations in a specific frequency band in the direction of drill move and focusing on torque changes in the same frequency band. The proposed method also has the advantage of being less susceptible to vibration and noise caused by cutting vibration and magnetic flux distribution of the motor by appropriately selecting the frequency band in which vibration is superimposed. The effectiveness of the proposed method was verified through experiments, and penetration detection was achieved even when the penetration surface and cutting direction were inclined from vertical.
