An ultrasound scaler tip and an ultrasound scaler having a high sterilization effect are provided. A toothbrush having a reduced effect on the interior of the mouth is provided.An ultrasound scaler tip 1 has a tip body 11 and an optical fiber 12. The tip body 11 has a tubular shape with a pointed-end opening and a rear-end opening, a rear end that can be attached to the ultrasound scaler body 2, and an intermediate curved part 16. The optical fiber 12 is thinner than the minimum inner diameter of the tip body 11 and has a rear end toward which light from the light source can enter. The optical fiber 12 is inserted from the rear-end opening to the pointed-end opening of the tip body 11, and has an intermediate part that is in contact with the curved part 16, so that the end is vibrated by ultrasonic vibration of the tip body 11. The ultrasound scaler body 2 houses a liquid supply means, an ultrasound-generating means, and a light source, which is attached to the rear end of the ultrasound scaler tip 1. The light source causes light for sterilization in a predetermined wavelength range to enter the rear end of the optical fiber 12.