The possibility of toothache after filling is related to secondary caries, deeper cavities, drug stimulation, biting hard objects and other factors. It is recommended that patients go to the hospital in time to clarify the cause of the disease. 1. Secondary caries: secondary caries occurs inside the tooth after filling, the reason is mainly because the cavity is not completely cleaned out when filling, so it leads to toothache after filling. At this time, you need to consult a doctor in time, take out the filling material, and then fill it again. 2. Deeper cavities: the doctor exposed the nerve during the treatment of the tooth, but did not find it, and filled the tooth directly, the nerve is continuously stimulated, which triggered the symptom of toothache after filling. 3. Drug stimulation: the material used to fill the deeper parts of the tooth may produce a certain amount of stimulation of the pulp, which leads to the occurrence of toothache. Anti-inflammatory drugs can be used to alleviate the pain, after a period of time to relieve the pain does not need to be treated. 4. Biting hard objects: patients bite hard objects with the filled teeth after filling, which leads to strong pressure on the teeth and causes biting pain. In addition to the above reasons, we cannot rule out other causes, and should consult the doctor in time.