It is more common to have buckling pain when treating the affected tooth, some of the affected tooth is inflammatory infection before treatment already has buckling pain, there are also buckling pain caused by improper operation in the treatment process. In the root canal treatment of the affected tooth appeared buckle pain for the following reasons: 1, in the preparation of the root canal, did not determine the length of the root canal and damage the root tip, this situation generally to the patient follow-up will appear when the affected tooth has + + buckle pain. If the FC is sealed, the buckle pain is even more powerful will appear + + +. If there is a double buckling pain caused by apical injury and drug stimulation, if there is a seal FC, it is generally best to drain the tooth for two days before sealing the drug, if it is only a simple root expansion that causes apical hole damage, the buckling pain can be sealed directly at the follow-up, and the root canal can be sealed with calcium hydroxide + iodoform for one week. If it is sealed with FC, then seal again after one drainage. All must determine the length of the root canal, otherwise there will be root canal smooth old change of medicine old buckle pain situation. 2, not yet root canal preparation, the affected tooth already has buckle pain, this situation is generally to drainage and with antibiotic treatment, general antibiotics to spiramycin + metronidazole + VC + dexamethasone oral medication. 3, there is a deactivator time too often caused by drug apical inflammation buckle pain, this situation must be extracted clean pulp, root canal expansion and cleaning after the first drainage once, the next seal on calcium hydroxide + iodoform + plus dimethoate powder for a week.