[Problem] To provide an ultrasound scaler chip and an ultrasound scaler which provide a high sterilization effect and to provide a tooth brush which less affects the inside of the mouth. [Solution] An ultrasound scaler chip (1) has a chip body (11) and an optical fiber (12). The chip body (11) has a tubular shape with a front end opening and a rear end opening. The chip body (11) also has a rear end that can be attached to an ultrasound scaler body (2) and an intermediate curved part (16). The optical fiber (12) is thinner than the minimum inner diameter of the chip body (11) and has a rear end on which light from a light source can be incident. The optical fiber (12) is inserted into the chip body (11) from the rear end opening to the front end opening with an intermediate part contacting the curved part (16) so that a front end can be vibrated by ultrasound vibrations of the chip body (11). The ultrasound scaler body (2) accommodates a liquid supply means an ultrasound generation means and the light source and is attached to the rear end of the ultrasound scaler chip (1). The light source causes sterilizing light of a predetermined wavelength region to be incident upon the rear end of the optical fiber (12).
