If the gum is swollen and painful inside, if it is the last tooth, it may be caused by a blind pocket in the gum, which produces food impaction or bacterial infection. This is usually done by localized peri-coronal rinsing, using 3% hydrogen peroxide and saline alternately to rinse out the food debris and pus, and then topical medication, iodine glycerin can be used locally, while mouthwash is usually recommended for anti-inflammatory treatment, commonly used with compound chlorhexidine rinse, or rehabilitation new liquid. If the gum swelling is due to inflammation in the apical part of the tooth, and there is a low density shadow in the apical part of the tooth on radiographs, this kind of root canal treatment is the best option to heal the tooth disease. If the swollen gums are caused by periodontal disease and there is tartar around the gums to stimulate the gums to produce redness and swelling, but there is no problem with the roots of the teeth, choose to do periodontal scaling treatment so that the swollen gums can be promoted to subside.