Whether the filling produces pain or not depends on the specific situation, if the cavity is located in the enamel layer, it can be filled by simple cavity preparation only, there is no distribution of nerve endings, and no pain will be produced. If the cavity is located in the deep layer of dentin, if the cavity is not bedded after removing the decayed material, the chemical substances released by the filling material and the external cold and heat stimulation will be transmitted to the pulp cavity, resulting in sensitivity and pain, and the original filling must be removed and re-bedded before repair. If the deeper cavity is accidentally penetrated during the process of decay preparation, it can cause pulpitis, and the pain is more intense, so the pulp must be removed under local anesthesia to complete the root canal treatment.