So severe could these permanent stains be, in fact, sometimes entire teeth were splotched the color of chocolate candy.
This is the story of how dental science discovered-and ultimately proved to the world-that fluoride, a mineral found in rocks and soil, prevents tooth decay.
Although dental caries remains a public health worry, it is no longer the unbridled problem it once was, thanks to fluoride. Mc Kay (r) persuaded the Colorado State Dental Association to invite Dr.
Green Vardiman Black (l), one of the nation's most eminent dental researchers, to attend 1909 convention where Mc Kay's findings were to be presented.
The two men began joint research and discovered other areas of the country where brown staining of teeth occurred.
Fluorine is the first element in the group of halogens which occupies the 17th column of the periodic table. It is a fairly rare element in the universe, but is the thirteenth most common element in the Earth's crust. It is also the most electronegative of the elements, meaning that it attracts electrons towards itself.