Fluoride and Dental healthFluoride (said like floor-eyed) is a mineral that occurs naturally in soil, water, and air that has been shown to prevent cavities, or tooth decay. For the past several decades, fluoride has been added to community water supplies and oral care products such as toothpaste and mouth rinse. Fluoride works by strengthening the tooth’s hard outer surface called enamel. You can get fluoride by drinking tap water in communities where the public water system adds fluoride and by using fluoride toothpaste and mouth rinse, as well as from certain foods and beverages. In the dental office, a dentist can apply fluoride varnish or gel, and in some public health programs, children can have fluoride varnish applied to their teeth. Fluoride can prevent tooth decay across the lifespan; both children and adults benefit from it.