How was the link between fluorides and tooth decay discovered?

Answer 1

A dentist named Fredrick McKay back in 1901, noticed a number of his patients had an unusual brownish stain on their teeth. He also noticed that the patients with this stain also had many less cavities than patients who did not show signs of the stain.

With a little investigation, the dentist found out that the patients with the stain were all born near and grew up in the same small community, Colorado Springs. He called it "Colorado Brown Stain" when he wrote about in the dental journals.

Years later, McKay had the town water supply tested and compared to the water of other communities. What he found was that the difference was the amount of naturally occurring fluoride was substantially higher in Colorado Springs where the patients who exhibited the brown stain than in towns where to stain was not evident.

Today we call that stain 'Fluorosis' and we know it is the result of children consuming excessive quantities of fluoride while their teeth are being formed in their jaws. In severe cases, the enamel fails to completely form, and we call this mottling.

We also know that if the proper amount of fluoride is consumed by children, they experience a significant decrease in the number of cavities they have over their lifetime without the accompanying stain.