Fluoride helps teeth in two ways. When children eat or drink fluoride in small doses, it enters the bloodstream and becomes part of their developing permanent teeth. Swallowed fluorides also become part of the saliva and strengthen teeth from the outside. Acids are less able to damage tooth enamel strengthened by fluoride.
In addition, people apply fluoride directly to their teeth when they use a fluoride toothpaste or rinse. Both children and adults also can receive fluoride treatments from the dentist. Fluoride applied to the outside of the teeth helps to speed remineralization. Fluoride treatments, applied in the dental office, also are strong enough to disrupt the production of acids by bacteria.
Fluoride in foods, supplements and water enters the bloodstream through the stomach. From there, it is absorbed into the body. In children, the fluoride then becomes available to the teeth that are developing in the jaw. Swallowed fluorides do not add fluoride to the teeth in someone older than age 16.
Topical fluoride products are applied directly to the teeth. They include toothpaste, mouth rinses and professionally applied fluoride treatments. Topical fluoride treatments are in the mouth for only a short time. However, fluoride levels in the mouth remain higher for several hours afterward.
Professional fluoride treatments are given in a dental office. They are applied as a gel, foam or varnish. The fluoride used for these treatments has a higher strength than over-the-counter or prescription mouthwashes or toothpastes.
Fluoride supplements also are available by prescription. They usually are reserved for children who live in areas where the water supply does not contain enough fluoride. Children who need supplements receive them from ages 6 months to 16 years.
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