Mouth/oral problems question. What can I do to prevent recurrent canker sores?

Some ways. The exact cause of canker sores is unknown. Reduce stress in ur life, make sure u don't have an ill-fitting denture, and make sure u have a balanced diet without deficiency of some essential vitamins, such as vit b, folic acid, or iron, will help. When it is really bad and frequent, u need to see ur doctor. Certain diseases, such as autoimmune diseases need to be ruled out.