Mouth ulcers use sprays, such as watermelon cream spray, stomatitis spray is better, you can take appropriate oral vitamins to promote its healing, commonly used is a multivitamin, mouth ulcers are caused by a lack of vitamin B group. If the mouth ulcer is large, it is recommended to use submucosal injection of drugs to promote healing, commonly used are prednisolone suspension, you can also apply local ointment-type drugs, such as tretinoin ointment or recombinant human epidermal growth factor gel. It is recommended to maintain oral hygiene, and if there are local irritants, such as root remnants, crown remnants or poor restorations that irritate the oral mucosa to produce ulcers, the irritants should be removed to promote rapid healing of the oral ulcer.