Fluoride (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.

What is fluoride, and how does it get into tap water?

Fluoride is a mineral that occurs naturally and is released from rocks into the soil, water, and air. Almost all water contains some fluoride, but usually not enough to prevent tooth decay.

Fluoride can also be added to drinking water supplies as a public health measure for reducing cavities. Decisions about adding fluoride to drinking water are made at the state or local level.

What are the common sources of fluoride?

The primary sources for fluoride intake include drinking water in fluoridated communities, toothpaste (if swallowed by young children), beverages and food processed with fluoridated water, dietary prescription supplements that include fluoride (e.g., tablets or drops), and other professional dental products (e.g., mouth rinses, gels, and foams).

What accounts for most of the fluoride intake?

In the United States, water and processed beverages (e.g., soft drinks and fruit juices) provide approximately 75% of a person’s fluoride intake.

Fluoride in the mouth (in the saliva and dental plaque) is an effective way to prevent tooth decay. Fluoride’s action in preventing tooth decay benefits both children and adults throughout their lives. The health benefits of fluoride are:

• Fewer and less severe cavities
• Less need for fillings and tooth extractions
• Less pain and suffering associated with tooth decay

How does fluoride work to prevent tooth decay?

Fluoride works by stopping or even reversing the tooth decay process—it keeps tooth enamel strong and solid. Tooth decay is caused by certain bacteria in the mouth. When a person eats sugar and other refined carbohydrates, these bacteria produce acid that removes minerals from the surface of the tooth. Fluoride helps to remineralize tooth surfaces and prevents cavities from forming.

How much fluoride is the right amount?

If your child is among the more than 200 million Americans who receive their water from a community water system fluoridated at the optimal level and if you follow instructions for your child’s tooth brushing, your child is receiving the right amount of fluoride to prevent tooth decay.

Children should start using toothpaste with fluoride when they are 2 years old. Younger children should only use toothpaste with fluoride if your child’s dentist or doctor recommends it. CDC recommends that children under 6 use a small, pea-sized amount of toothpaste, spit out the excess paste, and rinse well after brushing.

How do I know if fluoride is present in over-the-counter dental products?

In addition to toothpastes, other dental products such as mouth washes may contain fluoride. If so, they are regulated as drugs by the FDA and will be clearly labeled regarding ingredients, directions for use, and warnings, if any. Fluoride-containing products are safe and effective when used as directed, but young children (under age 6) should not use fluoride mouth rinse unless directed to do so by a dentist or doctor. Similarly, very young children (less than 2 years old) should only use toothpaste with fluoride if the child’s dentist or doctor recommends it.

What is fluoride?

Fluoride is a mineral your body needs to grow and be healthy. Fluoride makes teeth and bones strong, and it protects your teeth against decay. It can be found naturally in all soil, plants, animals and water.

How does fluoride help your teeth?

Fluoride is needed for infants and children, when teeth are still forming under the gums. The fluoride ingested at this time, in water or from vitamins that contain fluoride, deposits itself into the outer part of the tooth and makes the tooth stronger and better able to fight decay.

Fluoride also works after the teeth erupt and are present in your mouth. At this time, fluoride from water, food, toothpaste, mouthrinses and fluoride treatments received in a dental office washes over the teeth and helps to prevent decay or even stops small areas of decay that have already started. The fluoride makes the outer surface of the teeth stronger.

What is the best way to get fluoride?

Even though natural fluoride is found in food, plants, animals and water, the amount is usually too low to provide the best protection from decay. Illinois communities add small amounts of fluoride to their water supplies. This practice, called water fluoridation, ensures that the water contains the optimal level of fluoride. Drinking fluoridated water from birth can reduce decay by 40 percent to 65 percent.

People living in rural areas with private water wells do not have the benefits of water fluoridation. If, upon testing, a well’s natural fluoride content is insufficient, a dentist or physician can prescribe a vitamin with fluoride, in tablet or drop form. For best results, these tablets or drops should be taken from 6 months of age through 14 years of age.

Another way to get fluoride is through dental products such as toothpastes or mouthrinses that have the seal of the American Dental Association on the label. These products are good for children and adults, regardless of whether they drink fluoridated water.

In the United States, water fluoridation is not the only form of fluoride delivery that is effective in preventing tooth decay in people of all ages. Use the information listed below to compare the other fluoride products that may lower the risk for tooth decay, especially for people who are at higher risk for decay.

Although all of these products reduce tooth decay, combined use with fluoridated water offers protection greater than any of these products used alone.

Fluoride Toothpaste

Form
Concentrations of fluoride in toothpaste sold in the United States range from 1,000–1,500 ppm.

Use
Most people report brushing their teeth at least once per day, but more frequent use can offer additional protection. Fluoride in toothpaste is taken up directly by the dental plaque and demineralized enamel and also increases the concentration of fluoride in saliva.

Availability
Fluoride toothpaste is available over-the-counter and makes up more than 95% of toothpaste sales in the United States.

Recommendations
For most people (children, adolescents, and adults) brushing at least twice a day with a fluoride toothpaste—when you get up in the morning and before going to bed—is recommended.

Advice for Parents
For children aged 6 years and younger, some simple recommendations are advised to reduce the risk of dental fluorosis.

• Supervise brushing to discourage swallowing toothpaste.
• Place only a small pea-size amount of fluoride toothpaste on your child’s toothbrush.
• For children younger than 2, consult first with your doctor or dentist regarding the use of fluoride toothpaste.

Fluoride Mouth Rinse

Form
Fluoride mouth rinse is a concentrated solution intended for daily or weekly use. The most common fluoride compound used in mouth rinse is sodium fluoride. Over-the-counter solutions of 0.05% sodium fluoride (230 ppm fluoride) for daily rinsing are available for use by persons older than 6 years of age. Solutions of 0.20% sodium fluoride (920 ppm fluoride) are used in supervised, school-based weekly rinsing programs. Other concentrations also are available.

Use
Rinses are used daily or weekly for a prescribed amount of time. The fluoride from mouth rinse is retained in dental plaque and saliva to help prevent tooth decay.

Availability
Mouth rinses intended for home use can be purchased over-the-counter. Higher strength mouth rinses for those at high risk of tooth decay must be prescribed by a dentist or physician.

Recommendations
Children younger than 6 years of age should not use fluoride mouth rinse without consultation with a dentist or other health care provider because dental fluorosis could occur if such mouth rinses are repeatedly swallowed. Because fluoride mouth rinse has resulted in only limited reductions in tooth decay among schoolchildren, especially as their exposure to other sources of fluoride has increased, its use should be targeted to individuals or groups at high risk for decay.

Fluoride Supplements

Form
Tablets, lozenges, or liquids (including fluoride-vitamin preparations) are available. Most supplements contain sodium fluoride as the active ingredient. Tablets and lozenges are manufactured with 1.0, 0.5, or 0.25 mg fluoride.

Use
Fluoride supplements can be prescribed for children at high risk for tooth decay and whose primary drinking water has a low fluoride concentration. To maximize the topical effect of fluoride, tablets and lozenges are intended to be chewed or sucked for 1–2 minutes before being swallowed.

Availability
All fluoride supplements must be prescribed by a dentist or physician.

Recommendations
For children aged less than 6 years, the dentist, physician, or other health care provider should weigh the risk for tooth decay without fluoride supplements, the decay prevention offered by supplements, and the potential for dental fluorosis. Consideration of the child’s other sources of fluoride, especially drinking water, is essential in determining this balance. Parents and caregivers should be informed of both the benefit of protection against tooth decay and the possibility of dental fluorosis.

Fluoride Gel and Foam

Form
Fluoride gel is often formulated to be highly acidic (pH of approximately 3.0). Products available in the United States include gel of acidulated phosphate fluoride (1.23% [12,300 ppm] fluoride), gel or foam of sodium fluoride (0.9% [9,040 ppm] fluoride), and self-applied (i.e., home use) gel of sodium fluoride (0.5% [5,000 ppm] fluoride) or stannous fluoride (0.15% [1,000 ppm] fluoride).

Use
In a dental office, fluoride gel is applied for 1–4 minutes. Home use follows instructions provided on the prescription.

Availability
Most fluoride gel and foam applications are delivered in a dental office by a dental professional. These higher strength products, if used in the home, must be prescribed by a dentist or physician.

Recommendations
Because these applications are relatively infrequent, generally at 3 to 12–month intervals, fluoride gel poses little risk for dental fluorosis, even among patients younger than 6 years of age. Routine use of professionally applied fluoride gel or foam likely provides little benefit to persons not at high risk for tooth decay, especially those who drink fluoridated water and brush daily with fluoride toothpaste.

Fluoride Varnish

Form
Varnishes are available as sodium fluoride (2.26% [22,600 ppm] fluoride) or difluorsilane (0.1% [1,000 ppm] fluoride) preparations.

Use
High-concentration fluoride varnish is painted by dental or other health care professionals directly onto the teeth. Fluoride varnish is not intended to adhere permanently; this method holds a high concentration of fluoride in a small amount of material in close contact with the teeth for many hours. Varnishes must be reapplied at regular intervals with at least 2 applications per year required for effectiveness.

Availability
All fluoride varnish must be applied by a dentist or other health care provider.

Recommendations
No published evidence indicates that professionally applied fluoride varnish is a risk factor for dental fluorosis, even among children younger than 6 years of age. Proper application technique reduces the possibility that a patient will swallow varnish during its application and limits the total amount of fluoride swallowed as the varnish wears off the teeth over several hours.

Although it is not currently cleared for marketing by the Food and Drug Administration (FDA) as an anti-caries agent, fluoride varnish has been widely used for this purpose in Canada and Europe since the 1970s. Studies conducted in Canada and Europe have reported that fluoride varnish is as effective in preventing tooth decay as professionally applied fluoride gel.

Silver diamine fluoride (SDF) is gaining acceptance in the United States as a treatment to prevent, slow, or stop tooth decay. Using SDF can avoid the need to remove decay and fill a tooth. Applying SDF is easy. It is painless, and no local anesthesia is needed. Many oral health professionals use SDF in their practice.

How Silver Diamine Fluoride Works

SDF is a colorless liquid that is applied to teeth with a small brush. It contains silver, which kills germs that can cause tooth decay, as well as fluoride to prevent, slow down, or stop decay.

SDF can be put on teeth as soon as tooth decay is detected. It works best on primary (baby) teeth, especially front teeth. It may not work as well on back teeth, especially if there are large areas of decay. Often, back teeth need to be filled to prevent food from packing into the decayed area and to keep the child’s bite lined up properly. SDF works best if it is put on the decayed tooth more than once.

Answers to Questions Parents May Have About Silver Diamine Fluoride

• Why do dentists recommend SDF for children? Some children and/or parents are fearful of needles and dental drills and do not seek care. Dentists can use SDF to treat tooth decay instead of using needles or drills. SDF can also be used like fluoride varnish to prevent decay.
• What are the additional benefits of SDF? SDF is a good option for children, especially those who have trouble getting oral health care. For example:
  • Children who have difficulty cooperating with the dental staff, such as children who cannot sit still to get a filling or those with intellectual or developmental disabilities
  • Children who need two or more dental visits for treatment for severe tooth decay
  • Children who have a lot of decay can be treated with SDF in a dental office instead of a hospital operating room
• Who can apply SDF? It varies from state to state, but generally, dentists, dental hygienists, physicians, nurses, and their assistants may be legally allowed to apply SDF. Check with your state office of oral health to find out who can apply SDF in your state. All providers who apply SDF need training and should apply SDF using practice guidance set by professional dental or medical organizations.
• How often does SDF need to be put on tooth decay? Putting SDF on children’s teeth with decay every six to 12 months is recommended to slow down or stop decay. This is especially important for children who have decay in their back teeth.
• What does the tooth look like after SDF is put on tooth decay? After SDF is put on children’s teeth, the decayed spots will turn black and stay black (see photo). It may take up to a week for the decayed spots to turn black. Tooth enamel without decay will not turn black. The black stains on teeth treated with SDF are permanent.
• What information should be shared with parents about the black stains on teeth treated with SDF? Parents should be informed that decayed spots will turn black after SDF is put on teeth and that the stains are permanent. If it is applied to a primary tooth, the child’s permanent tooth that replaces it will not be stained. When this is explained clearly, most parents do not object to the use of SDF. If parents are still concerned about black stains on their child’s front teeth, the stains can be covered with a white filling.
• Are there any other side effects to SDF? Temporary brown or white stains may appear on children’s lips, skin, and gums that SDF touched. These stains may last up to three weeks. If SDF touches clothing, toys, blankets, or other items a child brings to the dental visit, the SDF will permanently stain the items.
• Should some children not get SDF? Because SDF contains silver, children with allergies to silver or who have sores or ulcers in their mouth should not get it. It should not be used when tooth decay has reached the pulp (center) of the tooth or if parents do not agree with having decayed areas on a child’s teeth turn black.
• Can SDF be used in addition to fluoride varnish? After SDF is applied, all teeth in the mouth may be treated with fluoride varnish to help prevent tooth decay on teeth not treated with SDF.
• If SDF is not used, what are other treatments? A child with tooth decay can have the decay removed and replaced with a filling. If the decay is severe, a crown (cap) may be needed, or the tooth may need to be pulled.

The mineral fluoride occurs naturally on earth and is released from rocks into the soil, water, and air. All water contains some fluoride. Usually, the fluoride level in water is not enough to prevent tooth decay; however, some groundwater and natural springs can have naturally high levels of fluoride.

Fluoride has been proven to protect teeth from decay. Bacteria in the mouth produce acid when a person eats sugary foods. This acid eats away minerals from the tooth’s surface, making the tooth weaker and increasing the chance of developing cavities. Fluoride helps to rebuild and strengthen the tooth’s surface, or enamel. Water fluoridation prevents tooth decay by providing frequent and consistent contact with low levels of fluoride. By keeping the tooth strong and solid, fluoride stops cavities from forming and can even rebuild the tooth’s surface.

Community water fluoridation is the process of adjusting the amount of fluoride found in water to achieve optimal prevention of tooth decay.

Although other fluoride-containing products, such as toothpaste, mouth rinses, and dietary supplements are available and contribute to the prevention and control of tooth decay, community water fluoridation has been identified as the most cost-effective method of delivering fluoride to all, reducing tooth decay by 25% in children and adults.

Benefits: Strong Teeth

Fluoride benefits children and adults throughout their lives. For children younger than age 8, fluoride helps strengthen the adult (permanent) teeth that are developing under the gums. For adults, drinking water with fluoride supports tooth enamel, keeping teeth strong and healthy. The health benefits of fluoride include having:

• Fewer cavities.
• Less severe cavities.
• Less need for fillings and removing teeth.
• Less pain and suffering because of tooth decay.

History of Fluoride in Water

In the 1930s, scientists examined the relationship between tooth decay in children and naturally occurring fluoride in drinking water. The study found that children who drank water with naturally high levels of fluoride had less tooth decay. This discovery was important because during that time most children and adults in the United States were affected by tooth decay. Many suffered from toothaches and painful extractions—often losing permanent teeth, including molars, even as teenagers.

After much scientific research, in 1945, the city of Grand Rapids, Michigan, was the first to add fluoride to its city water system in order to provide residents with the benefits of fluoride. This process of testing the water supply for fluoride and adjusting it to the right amount to prevent cavities is called community water fluoridation.

Since 1945, hundreds of cities have started community water fluoridation and in 2016, nearly 73% of the United States served by community water systems had access to fluoridated water. Because of its contribution to the dramatic decline in tooth decay over the past 70 years, CDC named community water fluoridation as 1 of 10 great public health achievements of the 20th century.

Cost: Saves Money, Saves Teeth

Community water fluoridation has been shown to save money, both for families and the health care system. The return on investment for community water fluoridation varies with size of the community, increasing as the community size increases. Community water fluoridation is cost-saving, even for small communities. The estimated return on investment for community water fluoridation (including productivity losses) ranged from $4 in small communities of 5,000 people or less, to $27 in large communities of 200,000 people or more.

Fluoride in the Water Today

In 2018, community water systems that contain enough fluoride to protect teeth served more than 200 million people or 73% of the US population. Because it is so beneficial, the United States has a national goal for 77% of Americans to have water with enough fluoride to prevent tooth decay by 2030.

What is fluoride, and where is it found?

Fluoride is the name given to a group of compounds that are composed of the naturally occurring element fluorine and one or more other elements. Fluorides are present naturally in water and soil at varying levels.

In the 1940s, scientists discovered that people who lived where drinking water supplies had naturally occurring fluoride levels of approximately 1 part fluoride per million parts water or greater (>1.0 ppm) had fewer dental caries (cavities) than people who lived where fluoride levels in drinking water were lower. Many more recent studies have supported this finding.

It was subsequently found that fluoride can prevent and even reverse tooth decay by inhibiting bacteria that produce acid in the mouth and by enhancing remineralization, the process through which tooth enamel is “rebuilt" after it begins to decay.

In addition to building up in teeth, ingested fluoride accumulates in bones.

What is water fluoridation?

Water fluoridation is the process of adding fluoride to the water supply so the level reaches approximately 0.7 ppm, or 0.7 milligrams of fluoride per liter of water; this is the optimal level for preventing tooth decay.

When did water fluoridation begin in the United States?

In 1945, Grand Rapids, Michigan, adjusted the fluoride content of its water supply to 1.0 ppm and thus became the first city to implement community water fluoridation. By 2008, more than 72 percent of the U.S. population served by public water systems had access to fluoridated water.

The Centers for Disease Control and Prevention (CDC) considers fluoridation of water one of the greatest achievements in public health in the 20th century.

Can fluoridated water cause cancer?

A possible relationship between fluoridated water and cancer risk has been debated for years. The debate resurfaced in 1990 when a study by the National Toxicology Program, part of the National Institute of Environmental Health Sciences, showed an increased number of osteosarcomas (bone tumors) in male rats given water high in fluoride for 2 years. However, other studies in humans and in animals have not shown an association between fluoridated water and cancer.

In a February 1991 Public Health Service (PHS) report, the agency said it found no evidence of an association between fluoride and cancer in humans. The report, based on a review of more than 50 human epidemiologic (population) studies produced over the past 40 years, concluded that optimal fluoridation of drinking water “does not pose a detectable cancer risk to humans” as evidenced by extensive human epidemiologic data reported to date.

In one of the studies reviewed for the PHS report, scientists at NCI evaluated the relationship between the fluoridation of drinking water and the number of deaths due to cancer in the United States during a 36-year period, and the relationship between water fluoridation and number of new cases of cancer during a 15-year period. After examining more than 2.2 million cancer death records and 125,000 cancer case records in counties using fluoridated water, the researchers found no indication of increased cancer risk associated with fluoridated drinking water.

In 1993, the Subcommittee on Health Effects of Ingested Fluoride of the National Research Council, part of the National Academy of Sciences, conducted an extensive literature review concerning the association between fluoridated drinking water and increased cancer risk. The review included data from more than 50 human epidemiologic studies and six animal studies. The Subcommittee concluded that none of the data demonstrated an association between fluoridated drinking water and cancer. A 1999 report by the CDC supported these findings. The CDC report concluded that studies to date have produced “no credible evidence” of an association between fluoridated drinking water and an increased risk for cancer. Subsequent interview studies of patients with osteosarcoma and their parents produced conflicting results, but with none showing clear evidence of a causal relationship between fluoride intake and risk of this tumor.

In 2011, researchers examined the possible relationship between fluoride exposure and osteosarcoma in a new way: they measured fluoride concentration in samples of normal bone that were adjacent to a person’s tumor. Because fluoride naturally accumulates in bone, this method provides a more accurate measure of cumulative fluoride exposure than relying on the memory of study participants or municipal water treatment records. The analysis showed no difference in bone fluoride levels between people with osteosarcoma and people in a control group who had other malignant bone tumors.

More recent population-based studies using cancer registry data found no evidence of an association between fluoride in drinking water and the risk of osteosarcoma or Ewing sarcoma.

Fluorides are naturally occurring compounds. Low levels of fluorides can help prevent dental cavities. At high levels, fluorides can result in tooth and bone damage. Hydrogen fluoride and fluorine are naturally-occurring gases that are very irritating to the skin, eyes, and respiratory tract. These substances have been found in at least 188 of the 1,636 National Priorities List sites identified by the Environmental Protection Agency (EPA).

What are fluoride, hydrogen fluoride, and fluorine?

Fluorides, hydrogen fluoride, and fluorine are chemically related. Fluorine is a naturally-occurring, pale yellow-green gas with a sharp odor. It combines with metals to make fluorides such as sodium fluoride and calcium fluoride, both white solids. Sodium fluoride dissolves easily in water, but calcium fluoride does not. Fluorine also combines with hydrogen to make hydrogen fluoride, a colorless gas. Hydrogen fluoride dissolves in water to form hydrofluoric acid.

Fluorine and hydrogen fluoride are used to make certain chemical compounds. Hydrofluoric acid is used for etching glass. Other fluoride compounds are used in making steel, chemicals, ceramics, lubricants, dyes, plastics, and pesticides. Fluorides are often added to drinking water supplies and to a variety of dental products, including toothpaste and mouth rinses, to prevent dental cavities.

What happens to fluoride, hydrogen fluoride, and fluorine when they enter the environment?

• Fluorine cannot be destroyed in the environment; it can only change its form. Fluorine forms salts with minerals in soil.
• Hydrogen fluoride gas will be absorbed by rain and into clouds and fog to form hydrofluoric acid, which will fall to the ground.
• Fluorides released to the air from volcanoes and industry are carried by wind and rain to nearby water, soil, and food sources.
• Fluorides in water and soil will form strong associations with sediment or soil particles.
• Fluorides will accumulate in plants and animals. In animals, the fluoride accumulates primarily in the bones or shell rather than in soft tissues.

How might I be exposed to fluoride, hydrogen fluoride, and fluorine?

• The general population can be exposed to fluorides in
  contaminated air, food, drinking water and soil.
• People living in communities with fluoridated water or high
  levels of naturally-occurring fluoride may be exposed to
  higher levels.
• People who work or live near industries where fluoride containing substances are used may be exposed to higher levels.

How can fluoride, hydrogen fluoride, and fluorine affect my health?

Small amounts of fluoride help prevent tooth cavities, but high levels can harm your health. In adults, exposure to high levels of fluoride can result in denser bones. However, if exposure is high enough, these bones may be more fragile and brittle and there may be a greater risk of breaking the bone. In animals, exposure to extremely high doses of fluoride can result in decreased fertility and sperm and testes damage.

Fluorine and hydrogen fluoride are very irritating to the skin, eyes, and respiratory tract. At high levels, such as may occur through exposure from an industrial accident, hydrogen fluoride may also damage the heart.

How likely are fluoride, hydrogen fluoride, and fluorine to cause cancer?

Most of the studies of people living in areas with fluoridated water or naturally high levels of fluoride in drinking water did not find an association between fluoride and cancer risk. Two animal cancer studies were inconclusive. The international Agency for Research on Cancer (IARC) has determined that the carcinogenicity of fluoride to humans is not classifiable.

How does fluoride, hydrogen fluoride, and fluorine affect children?

When used appropriately, fluoride is both safe and effective in preventing and controlling cavities. Drinking or eating excessive fluoride during the time teeth are being formed (before 8 years of age) can cause visible changes in teeth. This condition is called dental fluorosis. At very high concentrations of fluoride, the teeth can become more fragile and sometimes can break.

No studies have addressed whether low levels of fluoride will cause birth defects in humans. Birth defects have not been found in most studies of animals.

How can families reduce their risk for exposure to fluoride, hydrogen fluoride, and fluorine?

In the home, children may be exposed to high levels of fluorides if they swallow dental products containing fluoridated toothpaste, gels, or rinses. Parents should supervise brushing and place at most, a small pea size dab of toothpaste on the brush and teach children not to swallow dental products. People who live in areas with high levels of naturally-occurring fluoride in the water should use alternative sources of dinking water, such as bottled water.

Is there a medical test to show whether I've been exposed to fluoride, hydrogen fluoride, and fluorine?

Tests are available to measure fluoride levels in urine; these tests can determine if you have been exposed to higher-than normal levels of fluorides. The urine test must be performed soon after exposure because fluoride that is not stored in bones leaves the body within a few days. The test cannot be performed in the doctor's office, but can be done at most laboratories that test for chemical exposure. The urine fluoride test cannot be used to predict the nature or severity of toxic effects. Bone sampling can be done in special cases to measure long-term exposure to fluorides.

Has the federal government made recommendations to protect human health?

The EPA has set a maximum amount of fluoride allowable in drinking water of 4.0 milligrams per liter of water (4.0 mg/L). For the prevention of dental decay, the Public Health Service (PHS) has, since 1962, recommended that public water supplies contain between 0.7 and 1.2 milligrams of fluoride per liter of drinking water.

The Occupational Safety and Health Administration (OSHA) has set limits of 0.2 milligrams per cubic meter (0.2 mg/m³) for fluorine, 2.0 mg/m³ for hydrogen fluoride, and 2.5 mg/m³ for fluoride in workroom air to protect workers during an 8-hour shift over a 40-hour work week.

Fluoride is the safest and best way to prevent tooth decay. Fluoride is obtained from a variety of sources, including community fluoridated water, fluoride toothpaste, fluoride varnish, and fluoride supplements.

Fluoride supplements are recommended for children ages 6 months to 16 years who are determined to be at high risk for dental caries (tooth decay) and whose primary source of drinking water does not contain the right amount of fluoride that is naturally found in water. Unlike dietary supplements, fluoride supplements can't be purchased over the counter. Fluoride supplements require a prescription from a dentist, physician, or nurse practitioner. Fluoride supplements come in tablets, drops, or lozenges. Parents should give the supplement to the child each day for it to work best to prevent tooth decay.

Determining a Child's Need for Fluoride Supplements

The dentist, physician, or nurse practitioner will consider all sources of fluoride that a child receives (for example, fluoridated water, fluoride toothpaste, fluoride varnish, multi-vitamin containing fluoride) to determine if a child needs a fluoride supplement.

Below are simple questions that the child's dentist, physician, or nurse practitioner will consider to determine if the child should take fluoride supplements.

• Is the family's primary source of drinking water fluoridated? Many towns and cities add fluoride to their water supplies. If a family's water supply comes from a well, it will need to be tested to determine whether the right amount of fluoride is in the water. The public health department can advise families on how to have their home well water tested. Test results can be reviewed by the child's dentist, physician, or nurse practitioner to determine if fluoride supplements are needed.
• What is the child's primary source of drinking water? Some parents choose to give their child bottled water instead of tap water. Bottled water is an extra expense; in addition, most brands do not contain the right amount of fluoride to prevent tooth decay. Bottled water companies are not required to list fluoride on product labels unless the fluoride content is within set limits. If the bottled water label does not provide information about fluoride content, the bottled water company can be contacted and asked to provide this information.

• Find the amount of fluoride in your community’s water by checking with your local water utility. Although some bottled waters have the recommended amount of fluoride, many do not. If you have well water, it will need to be tested for fluoride concentration. Your dentist or local health department may be able to assist you.
• Brush with a fluoride toothpaste twice a day, floss regularly, and see a dentist for routine check-ups.
• Ask your child’s dentist or doctor about fluoride toothpaste use. You should not use fluoride toothpaste for children younger than age 2 unless you have been advised to do so by a dentist or doctor.