The main function of teeth is not only eating and talking, but also the important aesthetic function. When tooth decay occurs, it will be blackened and broken, and there will be soreness when eating cold or hot food, which not only makes people feel uncomfortable, but also affects the aesthetics and needs to be repaired. In the front wufeixiong teeth, it is more important to restore the aesthetic function of the teeth than to restore the chewing function. Especially in some special industries, such as actors, teachers, PR ladies, hotel attendants and so on. It is impossible to imagine what it would feel like to have snow-white, neat teeth mixed with some off-color restorations, such as silver-gray amalgam. Suppose a beautiful PR lady has a few silvery gray restorations on her front teeth, her success rate with clients will be greatly reduced. It is common to see that the first reaction of a patient after a filling is to take a closer look in the mirror to see if the filling is aesthetically pleasing. The introduction of composite resin is admittedly the next breakthrough in the history of dental materials. The most important characteristics of composite resin are its beautiful color, which is in harmony with the natural tooth color, and its chemical stability, which is insoluble in saliva. As soon as it was created, it was accepted by dentists and patients alike. Although the early composite resins were less resistant to pressure and abrasion and had a monotonous color, they could only be used for the restoration of anterior teeth. With the continuous development of dental materials, the physical properties of composite resins have been greatly improved through continuous improvement. At present, the color of composite resin has developed from 1-2 colors to dozens of colors; and there are various varieties of composite resin, including composite resin for anterior teeth, composite resin for posterior teeth, and composite resin for anterior and posterior teeth. After the restoration, the teeth can be completely fake, and even professional dentists can hardly tell where the fillings have been made without careful identification. Composite resin is a polymer filling material, which consists of a resin matrix and some inorganic fillers such as quartz glass, ceramic, silica, etc. Some barium and lanthanum are also added which can play a role in blocking X-rays, so that it is easy to check the teeth after restoration.