When a cavity needs to be repaired, the price of the filling is determined by the different materials used to fill the tooth. At present, there are two types of filling materials commonly used in the clinic: the first one is the cementitious material formed by mixing water and powder, and the price of this material is relatively cheap, ranging from 50-200 RMB. The second, is formed by light curing photosensitive resin material, this material in the clinical domestic within 200 yuan, imported in more than 300 yuan. Photosensitive resin aesthetics and strength are better than the ordinary cement-like materials, in the current clinical application is more.