Keeping kids' teeth healthy requires more than just daily
brushing. During a routine well-child exam, you may be surprised to
find the doctor examining your child's teeth and asking you
about your water supply. That's because fluoride, a substance
that's found naturally in water, plays an important role in
healthy tooth development and cavity prevention.
What Is Fluoride?
Fluoride exists naturally in water sources and is derived from
fluorine, the thirteenth most common element in the Earth's
crust. It is well known that fluoride helps prevent and even
reverse the early stages of tooth decay.
Tooth decay occurs when plaque - that sticky film of bacteria
that accumulates on your teeth - breaks down sugars in food. The
bacteria produce damaging acids that dissolve the hard enamel
surfaces of teeth. If the damage is not stopped or treated, the
bacteria can penetrate through the enamel causing tooth decay (also
called cavities or caries). Cavities weaken teeth and can lead to
pain, tooth loss, or even widespread infection in the most severe
Fluoride combats tooth decay in two ways. It is incorporated
into the structure of developing teeth when it is ingested and also
works when it comes in contact with the surface of the teeth.
Fluoride prevents the acid produced by the bacteria in plaque from
dissolving, or demineralizing, tooth enamel, the hard and shiny
substance that protects the teeth. Fluoride also allows teeth
damaged by acid to repair, or remineralize, themselves. Fluoride
cannot repair cavities, but it can reverse low levels of tooth
decay and thus prevent new cavities from forming.
Despite the good news about dental health, tooth decay remains
one of the most common diseases of childhood. According to the
Centers for Disease Control and Prevention (CDC), more than one
quarter of 2- to 5-year-olds and half of kids 12 to 15 years old
have one or more cavities, and tooth decay has affected two thirds
of 16- to 19-year-olds.
Fluoride and the Water Supply
For over 60 years, water fluoridation has proved to be a safe
and cost-effective way to reduce dental caries. Today, water
fluoridation is estimated to reduce tooth decay by 20-40%. As of
2002, the CDC statistics show that almost 60% of the U.S.
population receives fluoridated water through the taps in their
homes. Some communities have naturally occurring fluoride in their
water; others add it at water-processing plants.
Your child's doctor or dentist may know whether local water
supplies contain optimal levels of fluoride, between 0.7 and 1.2
ppm (parts fluoride per million parts of water). If your water
comes from a public system, you could also call your local water
authority or public health department, or check online at the
Environmental Protection Agency's (EPA) database of local water
safety reports. If you use well water or water from a private
source, fluoride levels should be checked by a laboratory or public
Some parents purchase bottled water for their children to drink
instead of tap water. Most bottled waters lack fluoride, but
fluoridated bottled water is now available. If fluoride is added,
the manufacturer is required to list the amount. If fluoride
concentration is greater than 0.6 ppm up to 1.0 ppm, you might see
the health claim "Drinking fluoridated water may reduce the
risk of tooth decay" on the label.
The Controversy Over Fluoride
Opponents of water fluoridation have questioned its safety and
effectiveness; however, there has been little evidence to support
Scientific research continues to support the benefits of
fluoride when it comes to prevention of tooth decay and its safety
at current recommended levels of 0.7 to 1.2 ppm. Dramatic
reductions in tooth decay in the past 30 years is attributed to
fluoridation of the water supply, and parents and health
professionals should continue to ensure that kids receive enough
fluoride to prevent cavities.
The American Dental Association (ADA), the United States Public
Health Service (USPHS), the American Academy of Pediatric (AAP),
and the World Health Organization (WHO), among many other national
and international organizations, endorse community water
fluoridation. The CDC recognized fluoridation of water as one of
the 10 greatest public health achievements of the 20th century.
Kids' Fluoride Needs
So how much fluoride do kids need? In general, kids under the
age of 6 months do not need fluoride supplements. Your child's
6-month checkup offers a great chance to discuss fluoride
supplementation with a health professional. If you live in a
nonfluoridated area, your doctor or dentist may prescribe fluoride
drops, tablets, or vitamins after your baby is 6 months old.
The AAP recommends that these fluoride supplements be given
daily to kids between the ages of 6 months and 16 years. The dosage
depends on how much fluoride naturally occurs in the water and the
child's age. Only kids living in nonfluoridated areas or those
who drink only nonfluoridated bottled water should receive
What about toothpastes, mouth rinses, and other products that
contain fluoride? Here are a few tips:
- Kids under 2 years old should not use fluoride toothpaste
unless instructed by a dentist or health professional.
- Kids younger than 6 may swallow too much toothpaste while
brushing, so should be supervised when brushing and taught to
spit, not swallow, toothpaste.
- Kids over age 2 should use a fluoride-containing toothpaste
that carries the ADA's seal of acceptance.
- Kids should use only a pea-sized amount of toothpaste.
- Kids under age 6 should never use fluoride-containing mouth
rinses. However, older kids at high risk for tooth decay may
benefit from using them. Your dentist can talk with you about
risk factors such as a family history of dental disease, recent
periodontal surgery or disease, or a physical impediment to
brushing regularly and thoroughly.
Your family dentist or pediatric dentist (one who specializes in
the care of children's teeth) is a great resource for
information about dental care and fluoride needs. A dentist can
help you understand more about how fluoride affects the teeth, and
once all of your child's primary teeth have come in, may
recommend regular topical fluoride during routine dental
Overexposure to Fluoride
If some fluoride is good, why isn't more fluoride better? As
with most medications, including vitamins and mineral supplements,
too much can be harmful. Most kids get the right amount of fluoride
through a combination of fluoridated toothpaste and fluoridated
water or supplements.
Too much fluoride before 8 years of age, a time when teeth are
developing, can cause enamel fluorosis, a discoloration or mottling
of the permanent teeth For most, the changes are subtle. In one
study, 94% of identified fluorosis cases were very mild to mild.
Most cases are due to inappropriate use of fluoride-containing
dental products, including toothpaste and mouth rinses. Sometimes
kids take daily fluoride supplements but may be getting adequate
fluoride from other sources, which also puts them at risk.
Recently, the National Research Council found naturally
occurring fluoride levels exceeded the optimal levels used in
community fluoridation programs (0.7 to 1.2 ppm), putting kids
under 8 years old at risk for severe enamel fluorosis. The CDC
recommends that in communities where fluoride levels are greater
than 2 ppm, parents should provide kids with water from other
The ADA also recognizes that infants need less fluoride than
older kids and adults. Some infants may be getting too much
fluoride in the water used to reconstitute infant formula. If
you're concerned that your infant may be getting too much
fluoride, talk with your doctor or dentist, who may recommend
ready-to-feed formula or formula reconstituted with fluoride-free
or low-fluoride water.
Very rarely, fluoride toxicity can occur when large amounts of
fluoride are ingested during a short period of time. Kids under age
6 account for more than 80% of reports of suspected overingestion.
Although outcomes are generally not serious, fluoride toxicity
sends several hundred children to emergency rooms each year.
Symptoms of fluoride toxicity may include nausea, diarrhea,
vomiting, abdominal pain, increased salivation, or increased
thirst. Symptoms begin 30 minutes after ingestion and can last up
to 24 hours. If you suspect your child may have eaten a substantial
amount of a fluoridated product or supplement, call the poison
control center or 911.
Be sure to keep toothpaste, supplements, mouth rinses, and other
fluoride-containing products out of children's reach or in a
locked cabinet. You should also supervise your young child's
toothbrushing sessions to prevent swallowing of toothpaste or other
If you have any questions about your water's fluoride
content, the fluoridated products your child uses, or whether your
child is receiving too much or too little fluoride, talk to your
doctor or dentist.
Mary L. Gavin, MD
Date reviewed: June 2008
Note: All information is for educational purposes only. For specific medical advice,
diagnoses, and treatment, consult your doctor.
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