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patient-flaxseed.html.
Tish Davidson, A.M.Fluoride
Definition
Fluoride is a naturally occurring element found in
waterand food. It is important for the development of
strong bones and teeth.
Purpose
In addition to occurring naturally in some water,
fluoride is added to toothpastes, mouthwashes, and
some public water supplies to prevent tooth decay
(dental caries).
Description
Fluoride is found naturally in seawater and in
some drinking water and is present in small amounts
in almost all soil, plants, and animals. In water, fluo-
ride dissolves to form a negatively charged ion (F-). In
the body, this ion is absorbed into the bloodstream
from the small intestine. It then binds withcalciumin
bones and teeth. The adult body contains less than
one-tenth of one ounce (about 2.5 g) of fluoride.
Ninety-five percent of this is found in bones and teeth.
The importance of fluoride for dental health has
been recognized since the 1930s when an association
between the fluoride content of drinking water and the
prevalence of dental caries was first noted. Acids
found in food or released by bacteria that feed on
sugar in the mouth cause tooth erosion. These acids
eat away at the enamel on the surface of the tooth.
Fluoride prevents tooth decay two ways. First, the
fluoride in saliva reacts with calcium and phosphate
in teeth to repair damage to the tooth’s surface. The
new surface formed when the tooth is repaired is
stronger than the original enamel and is better able
to resist decay. This process is called tooth remineral-
ization. Second, fluoride interferes with the metabolic
processes of bacteria in the mouth so that they pro-
duce less decay-causing acid.
Since teeth containing fluoride become stronger,
some researchers have suggested that fluoride might
also make bones stronger and prevent or delayosteo-
porosis(age related thinning of the bones). These
researchers have generally found that the amount of
fluoride that prevents tooth decay does not affect the
strength or density of bones. High doses of fluoride are
potentially toxic, and very large doses (5–15 times the
daily adequate intake) taken over time cause bones to
become chalky and brittle. Consequently, researchers
have concluded that fluoride supplements are not an
appropriate way to prevent or treat osteoporosis.Normal fluoride requirements
Fluoride, in the proper amount, can cut the level of
tooth decay in half and substantially reduce the amount
of money spent on dental care. Too much fluoride,
especially in children, results in a condition called den-
tal fluorosis. The surface of the teeth becomes discol-
ored by chalky white splotches. This is a cosmetic
problem only and does not affect the health of the teeth.
High doses of fluoride can be toxic. Doses
between 20–80 mg per day can result in changes in
bone that can be crippling, as well as changes in kidney
function, and possibly nerve and muscle function.
Doses as high as 5–10 g per day can be fatal.
The United States Institute of Medicine (IOM) of
the National Academy of Sciences developed values
calledDietary Reference Intakes(DRIs) for many
vitaminsandminerals. The DRIs consist of three
sets of numbers. The Recommended DietarySOURCE: American Dental AssociationSuggested amounts of dietary fluoride supplementsAge 0.3 ppm 0.3–0.6 ppm 0.6 ppm
Birth–6 months None None None
6 months–3 years 0.25 mg/day** None None
3 years–6 years 0.50 mg/day 0.25 mg/day None
6 years–16 years 1.0 mg/day 0.50 mg/day None
* 1.0 part per million (ppm) 1 milligram/liter (mg/L)
** 2.2 mg sodium fluoride contains 1 mg fluoride ionFluoride ion level in drinking water (ppm)*It is suggested that children between the ages of 6 months to
16 years living in non-fluoridated areas use dietary fluoride
supplements. Your dentist can prescribe the correct dosage
for your child based on the level of fluoride in your drinking
water.(Illustration by GGS Information Services/Thomson Gale.)Fluoride