Almost all drugs, medical products and techniques have some potential side effects, but we rarely hear much about those side effects when the risk is small or outweighed by the advantages. Fluoride is no different…we have known about its benefits for cavity prevention for nearly a century. So, why is it so controversial and what is the truth about this commonly used substance?
History of water fluoridation
In 1909 a dentist named Frederick McKay observed that some children in the Pike’s Peak region of Colorado developed a brown, mottled stain on their teeth; but despite the unattractive appearance, these children had relatively few cavities. After 22 years of research conducted by Dr. McKay and several other notable scientists, the cause of the phenomena was identified. Cryolite, an abundant mineral in the region, contains the element fluorine which was washed out during rain and snowstorms creating high concentrations (2-13 parts per million) of fluoride in the local water supply. By 1935 another researcher, Dr. H. Trendley Dean had concluded that when fluoride concentration in the water is maintained at about one part per million, tooth decay (caries) can be successfully prevented without the characteristic brown mottling of fluorosis.
Intentional fluoridation of the first U.S. public water system occurred in Grand Rapids, Michigan in 1945. The effect on the local school children was studied for 15 years and the fluoride was found to reduce tooth decay by 60%. In 1950, the American Dental Association officially accepted and encouraged the community water fluoridation as a means of caries prevention and today, about 67% of American communities benefit from this public health practice. Research has shown that as a result, the rate of tooth decay across America has been reduced by 29 % among children and 20%-40% among adults.
Benefits of Fluoride
Certain oral bacteria use the sugar and carbohydrates found in our food to produce acids that remove the minerals from the tooth. Over time, this demineralization weakens the teeth and leads to decay. Roots of the teeth, which are softer than the enamel and often exposed due to receding gums are especially vulnerable to decay and sensitivity.
Fluoride is absorbed into the enamel and root surfaces, forming a crystal that becomes part of the tooth structure, making it harder and more decay- resistant. Through this remineralization process it is actually possible to reduce sensitivity, stop the progression of early cavities and even reverse early tooth damage.
Although swallowing small amounts of fluoride is generally safe, it is not helpful. The real benefit of fluoride comes from frequent, low dose application to the surfaces of teeth that are already erupted. That is the reason it is found in so many different over the counter and prescription products, and often in the in the water supply.
Fluoride is an element, naturally occurring in concentrations typically too small to pose a problem- though it does accumulate in the body over time. That’s one of the reasons why it works so well to prevent cavities! On the other hand, ingesting very large quantities can be quite toxic, which is one reason why dental professionals recommend that children too young to “rinse and spit” should not be allowed to use fluoride toothpaste. Opponents of fluoridation have linked excessive fluoride intake to bone brittleness, cancer, and reproductive problems. Certainly, history has demonstrated that fluorosis (staining and brittleness) can occur when too much fluoride is swallowed during tooth development (before age 8).
Yet, the Center for Disease Control and prevention (CDC) named community water fluoridation as one of the “ten greatest public health achievements of the 20th century”… that that doesn’t mean that it is without controversy! The reason is an ethical one: Some people argue that putting fluoride in the community water supply takes away “informed consent” and obstructs the freedom to opt-out.
Just as with any other substance that is ingested, there are some precautions that should be taken regarding fluoride use. According to a study appearing in the Journal of the American Dental Association (2008), “There is weak and inconsistent evidence that the use of fluoride supplements prevents dental caries in primary teeth. There is evidence that such supplements prevent caries in permanent teeth. Mild-to-moderate dental fluorosis is a significant side effect.” Furthermore, the ADA recommends against using fluoridated water when preparing infant formula. Always confer with a dentist and pediatrician regarding the use of fluoride supplements for infants and children.
Caregivers should contact poison control if a child ingests a large amount of a fluoride-containing product like toothpaste, and they should be alert to signs and symptoms of overdose such as nausea, vomiting and abdominal pain. Drinking milk can inactivate the fluoride in the body and slow the toxic effects of a suspected overdose.
Fluoride is still a very safe, very effective and widely used method of preventing tooth decay – approved by the American Dental Association and the Food and Drug Administration both for children and adults. Current research indicates that most children are exposed to many more sources of fluoride (such as prescription or over-the-counter dental products, fluoride-containing sealants, filling and other dental materials, foods and beverages, etc.) than they once were. As a matter of fact, we have done such a good job as a society of finding ways to make it easily available to the public that most people no longer rely the water supply as a primary source of fluoride.
As a result, the U.S. Department of Health and Human Services and the U.S. Environmental Protection Agency announced in January 2010 its recommendation to reduce level of fluoride that is added to the public water supply. The new recommendations propose that fluoride in most drinking water be set at the low end of the optimal range to prevent tooth decay (0.7 milligrams of fluoride per liter of water replaces the current recommended range of 0.7 to 1.2 milligrams). The EPA is also initiating review of the maximum amount of fluoride allowed in drinking water.
Communities always test their water to determine how much (if any) extra fluoride should be added in order to achieve the optimal safe amount. After much discourse, Long Island no longer fluoridates the community water supply, but there are hidden sources of fluoride about which consumers should be aware: private wells, springs, and water bottled in other locations – even the water in canned vegetables may contain fluoride! The USDA maintains a database with information about the fluoride content in foods, and consumers can sometimes obtain information by contacting the manufacturer.
Like almost all drugs and other substances used in medicine, the trick is to regulate the amount and frequency of exposure so that we can reap the benefits without any unwanted side effects. Dentists and hygienists make it their business to know how much fluoride is in the water in the communities where their patients live before prescribing additional fluoride-containing products. Whether we realize it or not, dental professionals have always made recommendations for fluoride use on a case–by-case basis, considering not only a patient’s level of risk for developing cavities but also their current exposure level… so, you can confidently follow your dental providers’ advice about using the fluoride products they recommend.
For more information about fluoride, ask your dentist or dental hygienist and check out the Center for Disease Control and the American Dental Association .