Dental handpiece is the most common dental clinical treatment equipment, handpiece can be divided into dental high-speed handpiece and dental low-speed handpiece, its working principle is based on compressed air power, drive rotor high-speed rotation, thus promote dental burs to complete assignments of tooth drill grinding in the low speed handpiece machine and bending machine, and straight handpiece is for grinding and polishing, was used to treat,The bending is done orally.