The same pain after root canal treatment may be caused by instrument irritation, filling material irritation, secondary root canal infection, etc. Symptomatic treatment, medication, and secondary root canal treatment can be chosen according to different causes. 1. Instrument irritation: During root canal treatment, the instruments used cause stinging pain to the tissues around the root of the tooth. This is very common. Patients should try not to chew food with the bad tooth to avoid causing more pain, and take oral pain medication such as ibuprofen if necessary. 2. Filling material irritation: some people are sensitive body, allergic to fillings, may cause toothache. When the symptoms are not serious, pay more attention to oral hygiene, morning and evening brushing, meal logistics rinse, can also relieve the pain symptoms. If the pain continues to worsen, you should consult a doctor. 3. Root canal secondary infection: patients with root canal secondary infection is due to the root canal treatment process, bacteria into the root canal resulting in secondary inflammation, which can cause toothache. You can follow the doctor’s instructions for the second root canal treatment to relieve the toothache. Root canal treatment after the toothache, it is recommended to timely visit the hospital, clear causes, targeted treatment, to avoid delaying the condition. Under the guidance of the physician to use drugs.