Fluoride treatment, dental

Fluoride is a chemical found in many substances. In the human body, fluoride acts to prevent tooth decay by strengthening tooth enamel and inhibiting the growth of plaque-forming bacteria. After researchers discovered this characteristic of fluoride, fluoridation began. Fluoridation is the process of adding the fluoride to public water supplies.

McKay's Discovery

It all started in the early 1900s with Colorado dentist Frederick S. McKay. McKay noticed that many of his patients had brown stains, called "mottled enamel," on their teeth. McKay set out to find the cause with the help of Greene V. Black (1836-1915) of Northwestern University in Chicago, Illinois. By 1916, McKay and his team believed the mottling was caused by something in the patients' drinking water.

In 1931 McKay found what he was looking for. He discovered that people who drank water containing a high level of naturally-occurring fluoride had a high degree of tooth mottling. By the early 1940s the United States Public Health Service had already studies the connection between mottling and fluoride and established that one part per million was the ideal level of fluoride in drinking water. This amount substantially reducing decay but did not cause mottling.

Adding Fluoride

Following safety tests on animals, the Public Health Service conducted field tests. In 1945 the public water systems of Newburgh, New York, and Grand Rapids, Michigan, became the first ever to be artificially fluoridated with sodium fluoride. Simultaneously, a group of Wisconsin dentists led by John G. Frisch inaugurated fluoridation in their state.

Results of these tests seemed to show that fluoridation reduced dental cavities by as much as two thirds. Based on those results, the United States Public Health Service recommended in 1950 that all United States communities with public water systems fluoridate. Later that year the American Dental Association (ADA) followed suit, and the American Medical Association added its endorsement in 1951.

Controversy

Even though virtually the entire dental, medical, and public health establishment favored fluoridation, the recommendation was immediately controversial, and has remained so. Opponents objected to fluoridation because of possible health risks since fluoride is toxic (poisonous) in large amounts. Concerns were also raised about citizens being deprived of the choice whether or not to consume a chemical. Because of the controversy, only about 60 percent of the people in the United States now drink fluoridated water. Fluoridation is also practiced in about thirty other countries.

Fluoride and Toothpaste

The initial claims that fluoridation of drinking water produced two-thirds less tooth decay have been modified to about 20 to 25 percent. In recent years, other ways of applying fluoride have been developed. In the 1950s the Procter & Gamble Company had the idea of adding the chemical to toothpaste. In 1956 the company launched a major advertising campaign with their Crest brand of toothpaste. Four years later the Council on Dental Therapeutics of the ADA gave Crest its seal of approval as "an effective decay-preventive dentifrice." The ADA now estimates that brushing with fluoride-containing toothpaste reduces tooth decay by as much as 20 or 30 percent.

Fluoride can also be taken in tablet form, and as a solution either "painted" directly onto the teeth or swished around as a mouthwash.

[See also Toothbrush and toothpaste ]