The effect of dexamethasone in treating mouth ulcers is relatively good, dexamethasone is a hormonal drug that can inhibit the inflammatory reaction of the oral mucosa, reduce the destruction of the mucosal tissues, and promote the healing of the ulcer surface. However, dexamethasone is not recommended for long-term use in large quantities to prevent dependence. Dexamethasone is not recommended for the treatment of mouth ulcers in children. After the mouth ulcers appear, you can also apply watermelon cream spray, open throat sword spray, stomatitis spray, or use the rehabilitation of new liquid gargle, which can promote the healing of the ulcers. At the same time, patients should avoid eating spicy, stimulating food, eat more fresh vegetables and fruits, drink more water to supplement adequate vitamin C, in addition to pay attention to the maintenance of oral hygiene, carefully brushing teeth and gargling, to reduce the number of disease-causing bacteria in the mouth, which is very favorable to the healing of oral ulcers.