It is important to have pustules on the gums after root canal treatment. This situation is considered to be the tooth splitting, missing root canal and other cases, you need to go to the hospital in time to check and deal with. 1. Tooth splitting: after root canal treatment, the brittleness of the tooth increases, the toughness becomes smaller, and the tooth is prone to splitting. After the tooth splits, food debris and bacteria will enter the cracks of the tooth and become infected, resulting in pustules on the corresponding gums, which will need to be extracted after the diagnosis is confirmed by the examination. 2. Missing root canals: for the complexity of the root canal system, there will be secondary root canals, or the number of conventional root canals varies, resulting in the treatment of missing root canals, missed root canals infected with periapical periodontitis, pustules appear on the gums, need to be diagnosed in the CT examination of the missing root canals after the re-treatment. If pustules appear on the gums of the tooth after root canal treatment, it is necessary to consult a doctor for examination and treatment under the guidance of the doctor to avoid delaying the condition.