Background and objectives: The feeling of bone quality during drilling procedure is important to predict the prognosis of dental implant. Although we actually use a classification of D1, D2, D3 and D4 for this evaluation, it is just a subjective sensation by a surgeon. It means that the estimation of individual feeling is equivocal and we need a new definitive classification based on data to identify bone quality objectively. In order to solve this problem, we developed a telerobotic drilling system.

Methods: An original method for estimating the bone quality is proposed by modeling the relationship between the cutting force and the bone density. The bone density could be obtained in real time by comparing the force from a reaction force observer with the force from a thrust force formula with pre-estimated bone density parameters. The validity of the proposed method was confirmed through experiments using different types of wood mentioned in Misch fs bone quality classification.

Results: The experimental results indicated that the error of contact detection on the bone surface was ±50 μm and the error of bone density detection was 0.16 mm.

Conclusions: The proposed telerobotic drilling system achieved precise manipulation of the drill feed and vivid feedback from the cutting force.