Root canal treatment of apical infection, need to carry out local cleaning treatment, local medicine, if necessary, oral medication to control infection. 1. Local cleaning treatment: first of all, it is necessary to open the pulp drainage to ensure that the root canal is smooth, if there is a purulent reaction, it is necessary to cut and drain the pus as soon as possible, and remove the irritating factors. Local saline or hydrogen peroxide is used for rinsing to clean the residual tissue. 2. Local medication: For patients with severe inflammatory reactions, local medication such as iodized glycerin and iodophenol can be used to alleviate the symptoms. 3. Oral medication: if necessary, oral tinidazole, metronidazole and other drugs to control inflammation and infection, when the pain is severe, you can also take oral ibuprofen, acetaminophen and other painkillers. If there is any adverse reaction after root canal treatment, you need to consult a doctor in time and follow the doctor’s instructions to avoid unauthorized use of medication. Diet should be absolutely light and nutritious within a short period of time after treatment.