Fluoride: Nature’s Tooth Decay Fighter

A model of healthy aligned teeth

Cavities used to be a fact of life. However, during the past few decades, tooth decay has been reduced dramatically. The key reason: fluoride. Fluoride is a mineral that may occur naturally in all drinking water sources—oceans, lakes, rivers and underground water. Extensive research has shown that optimal levels of fluoride not only reduce caries in children and adults, but also help repair the early stages of tooth decay.


You may receive fluoride in topical or systemic forms. Topical fluoride (applied to the surface of the teeth) is delivered through many types of toothpaste, mouth rinses and gels, as well as through foams and varnishes applied in the dental office. Topical fluorides help strengthen the surface of the tooth enamel.

Systemic fluoride is intended to be ingested. This form includes fluoridated water and dietary fluoride supplements, such as tablets, drops and lozenges. Systemic fluoride is integrated into children’s teeth as their tooth structures form.

A reduction in tooth decay is achieved through exposure to topical fluorides, systemic fluorides or both. Water fluoridation provides both types of exposure.


Community water fluoridation is an effective and inexpensive means of achieving the fluoride exposure necessary to help prevent tooth decay. Studies show that water fluoridation continues to be effective in reducing tooth decay by about 20 to 40 percent.

Leading health organizations, including the American Dental Association (ADA), the U.S. Centers for Disease Control and Prevention (CDC), and the American Academy of Pediatric Dentistry (AAPD), support community water fluoridation on the basis of the overwhelming weight of scientific evidence, which continues to support its safety and effectiveness. Water fluoridation helps prevent tooth decay in children and adults.

The optimal fluoride level in drinking water is 0.7 to 1.2 parts per million. Naturally occurring fluoride that may be below or above these levels is present in some drinking water supplies.

If your drinking water comes from a public or community water supply, contact the local water supplier to determine the fluoride level. You also can check with your local, county or state health department.

If your drinking water comes from a private well, a certified laboratory can test samples and provide data. Contact your local or state health department for information about laboratories that provide this service.


In 1999, the EPA began requiring water suppliers to provide annual drinking water quality reports to their customers. Water quality reports typically may be mailed to the customer, placed in the local newspaper or made available through the Internet at about July 1 of each year. To obtain a copy of the report, contact your local water supplier. The name of the water system (often not the name of the city) can be found on your water bill. If the name of the system is unknown, contact the local health department. The EPA does not regulate private drinking water wells, but the agency recommends that private well water be tested every year.