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What did Frederick McKay discover about fluoride and tooth decay in Colorado?

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Dentistry — dentistry The practice of dentistry involves preventing, diagnosing, and treating oral disease, as well as correcting deformities of the jaws, teeth, and oral cavity.

In the early 20th century, American dentist Frederick McKay observed that many of his patients in Colorado exhibited a condition characterized by the mottling of their teeth. Notably, he discovered that these patients also experienced an almost total absence of dental decay.1

Following years of research, McKay and his colleagues determined that this resistance to cavities was caused by high levels of naturally occurring fluoride in the local drinking water. While excessive fluoride exposure can lead to dental fluorosis—a condition involving the mottling or pitting of teeth—this discovery proved that controlled levels of fluoride effectively protect teeth against decay.12

This finding was pivotal for public health, leading to the implementation of water fluoridation programs across the United States beginning in 1945. Since these programs were initiated, the incidence of dental caries in children has decreased by more than 50 percent.21