When the element fluoride is used in small amounts on a routine basis it helps to prevent tooth decay. It encourages “remineralization,” a strengthening of weak areas on the teeth. These spots are the beginning of cavity formation. Fluoride occurs naturally in water and in many different foods, as well as in dental products such as toothpaste, mouth rinses, gels, varnish and supplements. Fluoride is effective when combined with a healthy diet and good oral hygiene.