Fluoride in toothpaste and in drinking water protects the smooth surfacesofteeth but back teeth need extra protection.
牙膏和饮水中的氟化物能够保护牙齿的表面，但在后面的磨牙需要特别的保护。
2
Under the function of the brushing force, the brush wheels can do rolling and brushing work for the surfacesofteeth and can rotate on the bearing seat.
毛刷轮在刷拭力的作用下对牙齿表面进行滚动刷拭、并在轴承座上转动。
3
The wire was bonded with directly bonding technique to the labial or lingual surfacesofteeth according to the application steps of light-cure material.