Best dental clinic in Kovilambakkam Treatment for mouth ulcer The goal of treatment is to relieve symptoms. The underlying cause of the ulcer should be treated if it is known. Gently cleaning your mouth and teeth may help relieve your symptoms. Medicines that you rub directly on the ulcer. These include antihistamines, antacids, and corticosteroids that may help soothe discomfort. Avoid hot or spicy foods until the ulcer is healed.