抄録
Dentists and dental hygienists remove dental calculus using a cutting tool called dental scaler. The evaluation of sharpness of dental scalers requires skill which depends on sensory examination. The aim of this research is to evaluate the sharpness of scalers objectively by estimating optical reflection images of blades rotated in two directions. For taking photos of blades at various angles using CCD camera, the scaler to be inspected was fixed on a turn table driven by a stepping motor. In this research, the angle of a scaler fixture on the turn table was also changed by a RC servo motor. As a result, the optical reflection patterns of the cutting edge could be obtained more precisely than before. Next, an image processing method was examined for calculating the area and the length of optical reflection patterns of the cutting edge from the photos obtained from various angles. And the relation between these values and the sensory evaluated values was examined using multiple regression analysis. As a result, it was confirmed that this method can evaluate the sharpness of scalers objectively and precisely. And it was also confirmed that the angle of the scaler fixture is also an important factor for this evaluation method as well as the angle of the scaler.
