Abstract
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. An apparatus for taking photos of scalers was developed by taking into account the evaluation method of observing the cutting edge reflection used by experts. The scaler to be inspected was fixed on a turn table driven by a stepping motor. The angle of the scaler was changed by the stepping motor and the angle of a scaler fixture on the turn table was changed by a RC servo motor. And photos of the cutting edge of the scaler were taken from various angles by a CCD camera. Next, the relation between the optical reflection pattern of the cutting edge and the sensory evaluation was examined. As a result, the implications between them were found and the angle of the scaler fixture was also an important factor for evaluating the sharpness of the scaler as well as the angle of the scaler.
