Ultrasound scaler tip and ultrasound scaler has high sterilization effect. Toothbrush has reduced effect on mouth interior. An ultrasound scaler tip has tip body and optical fiber. Tip body has tubular shape with pointed-end opening and rear-end opening, rear end that can be attached to ultrasound scaler body, and intermediate curved part. Optical fiber is thinner than minimum inner diameter of tip body and has rear end toward which light from light source can enter. Optical fiber is inserted from rear-end opening to pointed-end opening of tip body, and has intermediate part that is in contact with curved part, so that end is vibrated by ultrasonic vibration of tip body. Ultrasound scaler body houses liquid supply device, ultrasound-generating device, and light source, which is attached to rear end of ultrasound scaler tip. Light source causes light for sterilization in predetermined wavelength range to enter rear end of optical fiber.