Mouth sores after surgery can be painful and invisible, and sometimes they can cause something very serious. They kept their checks if they did not disappear the day after the operation, wash your mouth with warm water gently. Your dentist or oral surgeon may assume that every time you rinse, add a teaspoon of salt to a glass of warm water. Rinse 4 or 5 times a day for 3 or 4 days. Some Herbal remedies are useful for mouth sores after surgery.