Research shows that fluoride reduces cavities in both children and adults by halting tooth decay. It also helps repair the early stages of tooth decay even before the decay becomes visible. Interestingly, many people continue to be misinformed about fluoride. It is a safe chemical component when used correctly. When your dentist applies fluoride to your teeth, usually in the form of a varnish, gel or foam, it is more concentrated than the fluoride contained in toothpaste or mouthwash. The ADA recommends that dental professionals use any of the professional strength products carrying the ADA Seal of Acceptance.