Keeping kids' teeth healthy means 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 found
naturally in water, plays an important role in healthy tooth development and cavity
Fluoride, which exists naturally in water sources, is derived from fluorine,
a 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 happens when plaque — that sticky film of bacteria that builds
up on 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 and cause 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.
It protects teeth 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
more than 25% of 2- to 5-year-olds have one or more cavities
half of kids 12 to 15 years old have one or more cavities
tooth decay affects two thirds of 16- to 19-year-olds
Fluoride and the Water Supply
For more than 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 2012, CDC statistics show that more than 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 doctor or dentist may know whether local water supplies contain optimal levels
of fluoride, which is 0.7 milligrams per liter of water (previously it was a
range of 0.7 to 1.2 milligrams). If your water comes from a public system,
you also can call your local water authority or public health department, or check
online at the Environmental Protection Agency's (EPA) database of local water safety
If you use well water or water from a private source, fluoride levels should be
checked by a laboratory or public health department.
Some parents buy bottled water for their kids 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 (parts per million), 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 these concerns.
Scientific research continues to show the benefits of fluoride when it comes to
prevention of tooth decay and its safety. 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
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. In fact, 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 your doctor.
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 dosage depends on
how much fluoride naturally occurs in the water and your child's age. Only kids living
in nonfluoridated areas or those who drink only nonfluoridated bottled water should
Here are some other tips:
Use a fluoride-containing toothpaste that carries the ADA's seal of acceptance.
Brush babies' teeth as they come in with an infant toothbrush. Use water and a
tiny bit of fluoride toothpaste (about the size of a grain of rice). If you are using
baby toothpaste without the fluoride, keep it to the same amount because you still
want to minimize any toothpaste that is swallowed.
Kids ages 3 and up should use only a pea-sized amount of fluoride toothpaste.
Kids younger than 6 may swallow too much toothpaste while brushing. Supervise
them when brushing and teach them to spit, not swallow, the toothpaste.
Kids under age 6 should never use fluoride-containing mouth rinses. But older
kids at high risk for tooth decay may benefit from 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 may
even recommend applying a topical fluoride varnish during routine dental visits.
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 accidental swallowing 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 that some naturally occurring fluoride
levels exceeded the optimal levels used in community fluoridation programs, putting
kids under 8 years old at risk for severe enamel fluorosis. The CDC recommends that
in communities where natural fluoride levels are high, parents should give kids water
from other sources.
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 poisoning can happen if 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 this is generally not serious,
fluoride poisoning sends several hundred children to emergency rooms each year.
Symptoms of fluoride poisoning 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 (1-800-222-1222)
Be sure to keep toothpaste, supplements, mouth rinses, and other fluoride-containing
products out of kids' reach or in a locked cabinet. Also, supervise young kids when
they brush their teeth to prevent swallowing of toothpaste or other fluoridated
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.