The materials used for dental fillings include glass ionomer and resin materials, and resin materials are relatively better. Filling is also called filling of teeth, which is a treatment method performed after the hard tissue of teeth is missing, if it is caused by tooth decay, the infected hard tissue of teeth is removed by using dental high-speed drill to terminate the progress of caries, and then a tight filling is performed, and the filling material used depends on the degree of tooth decay. In the early stage of tooth decay, it may only be the caries of the sulcus and the point gap of the tooth, in this case, the decayed part can be removed and then the filling of the tooth is carried out. Resin material can be chosen, mainly because the abrasion resistance of resin is better, and the micro-leakage between the material and the tooth after filling is smaller, so the possibility of secondary caries will be smaller in the future, so if the tooth decay is shallow, resin material can be chosen for filling as much as possible. If the tooth decay is deeper and close to the nerve, resin material can not be used directly to fill the tooth, calcium hydroxide can be used to protect the pulp, and then glass ion material can be used to fill the tooth, because the glass ion material can release fluorine, which can reduce the stimulation to the pulp tissue, and also the resin material can be used to seal the outermost layer of the tooth after the glass ion filling to reduce the occurrence of secondary caries. Therefore, the filling material should be resin-based filling material as much as possible, which is wear-resistant and not easy to produce secondary caries.