Red bumps on the gums after root canal treatment may be apical fistula, gingival papillitis, wisdom teeth pericoronitis, etc. 1. Apical fistula: usually located in the middle of the root or apical part of the tooth, “red bumps” is the apical inflammation drainage sinus openings, after root canal treatment, on behalf of the root canal treatment has failed, the need to re-root canal treatment. 2. Gingival papillitis: Most of the teeth treated with root canal therapy are defective due to caries, and inappropriate fillings are prone to form overhanging protrusions or food impaction, leading to inflammation and redness of the gums. It is necessary to remove the original filling and re-fill the treatment. 3. Wisdom tooth pericoronitis: some chronic recurrent inflammation of wisdom teeth can form fistula in the position of the first molar and second molar, which is not directly related to the first molar and second molar that have been treated with root canal. It is not directly related to the first and second molars which have been treated by root canal. It is necessary to remove the wisdom teeth after anti-inflammation. It is recommended to go to the stomatology department of the regular hospital, to be examined by a physician to make a clear diagnosis, and symptomatic treatment.