Fluoride is the negative ion of the element fluorine. It is represented by the chemical formula F-. It is widely found in nature, in trace amounts. It occurs naturally in air, soil, plants, rocks, fresh water, sea water and many foods. Fluoride plays a role in the mineralization of your bones and teeth, a process essential for keeping them hard and strong. In fact, about 99% of the body's fluoride is stored in bones and teeth. Fluoride is also important for preventing dental caries, also known as cavities. This is why it has been added to community water supplies in many countries. ► Read also: Why Dental Crowding Happens? Fuente: Youtube / Today I Found OutImage : Campaign for Dental Health