Hence, from the curious findings of Churchill’s lab assistant, the mystery of the brown stained teeth was cracked. But one mystery often ripples into many others. And shortly after this discovery, PHS scientists started investigating a slew of new and provocative questions about water-borne fluoride. With these PHS investigations, research on fluoride and its effects on tooth enamel began in earnest mobile dental unit. The architect of these first fluoride studies was Dr. H. Trendley Dean, head of the Dental Hygiene Unit at the National Institute of Health (NIH). Dean began investigating the epidemiology of fluorosis in 1931. One of his primary research concerns was determining how high fluoride levels could be in drinking water before fluorosis occurred. To determine this, Dean enlisted the help of Dr. Elias Elvove, a senior chemist at the NIH. Dean gave Elvove the hardscrabble task of developing a more accurate method to measure fluoride levels in drinking water. Elvove labored long and hard in his laboratory, and within two years he reported back to Dean with success. He had developed a state-of-the-art method to measure fluoride levels in water with an accuracy of 0 dental lab equipment.1 parts per million (ppm). With this new method in tow, Dean and his staff set out across the country to compare fluoride levels in drinking water. By the late 1930s, he and his staff had made a critical discovery. Namely, fluoride levels of up to 1.0 ppm in drinking water did not cause enamel fluorosis in most people and only mild enamel fluorosis in a small percentage of people.
Proof That Fluoride Prevents Caries
This finding sent Dean’s thoughts spiraling in a new direction. He recalled from reading McKay’s and Black’s studies on fluorosis that mottled tooth enamel is unusually resistant to decay. Dean wondered whether adding fluoride to drinking water at physically and cosmetically safe levels would help fight tooth decay. This hypothesis, Dean told his colleagues, would need to be tested.In 1944, Dean got his wish. That year, the City Commission of Grand Rapids, Michigan-after numerous discussions with researchers from the PHS, the Michigan Department of Health, and other public health organizations-voted to add fluoride to its public water supply the following year. In 1945, Grand Rapids became the first city in the world to fluoridate its drinking water.The Grand Rapids water fluoridation study was originally sponsored by the U.S dental vacuum forming machine. Surgeon General, but was taken over by the NIDR shortly after the Institute’s inception in 1948. During the 15-year project, researchers monitored the rate of tooth decay among Grand Rapids’ almost 30,000 schoolchildren. After just 11 years, Dean- who was now director of the NIDR-announced an amazing finding. The caries rate among Grand Rapids children born after fluoride was added to the water supply dropped more than 60 percent. This finding, considering the thousands of participants in the study, amounted to a giant scientific breakthrough that promised to revolutionize dental care, making tooth decay for the first time in history a preventable disease for most people.
A Lasting Achievement
Almost 30 years after the conclusion of the Grand Rapids fluoridation study, fluoride continues to be dental science’s main weapon in the battle against tooth decay. Today, just about every toothpaste on the market contains fluoride as its active ingredient; water fluoridation projects currently benefit over 200 million Americans, and 13 million schoolchildren now participate in school-based fluoride mouth rinse programs. As the figures indicate, McKay, Dean, and the others helped to transform dentistry into a prevention-oriented profession. Their drive, in the face of overwhelming adversity, is no less than a remarkable feat of science-an achievement ranking with the other great preventive health measures of our century.Introduction To Oral Doctors? for more information.