Tooth filling does not hurt when the decay is relatively shallow, and tooth filling may hurt when the decay is deeper. Tooth decay is shallow, only damage to the enamel level, away from the nerve is relatively far, fillings will be the surface of the decay, bacteria cleaning, and then fill the material, the irritation is small, the patient generally do not have pain, most can be tolerated. Tooth decay is deeper, caries up to the dentin close to the pulp cavity, in the filling will stimulate the dental nerve, which in turn triggers pain. If the decay has invaded the nerve, the filling treatment requires anesthesia to remove the necrotic nerve. Dental filling pain is based on the degree of caries and personal tolerance, caries is recommended to fill early to terminate the progress of caries. It is recommended to go to a regular hospital stomatology department.