For gum ulcers, you can apply watermelon cream spray, metronidazole film, tretinoin gel, compound furacilin paste, lidocaine gel, open throat sword spray and recombinant human epidermal growth factor gel locally to promote the healing of the ulcer, and you can also rinse with rehabilitative new liquid. A small number of gum ulcers are due to vitamin and trace element deficiencies and are also related to body fire, so you can take vitamin B and C tablets, zinc gluconate oral solution and iron supplements, as well as medications to clear heat and remove fire, such as clear fire gardenia and wheat tablets, stomatitis clear and niuhuang detoxification tablets. If the ulcers appear in the gums near the apical part of the tooth, there is also a possibility that the tooth suffers from chronic periapicalitis, chronic periapicalitis can lead to inflammation of the apical area, resorption of the alveolar bone, redness, swelling, breakage, fistula and even abscess at the gums, in the treatment can take cephalosporin or erythromycin with metronidazole to reduce inflammation, while the affected tooth should be root canal treatment.