If you want to get technical, fluoride is the reduced form of fluorine. Both organic and inorganic compounds containing the element fluorine are considered fluorides, for what it’s worth. As a halogen, fluorine forms a monovalent ion (−1 charge). The range of fluorides is considerable as fluorine forms compounds with all elements except He, Ne, and Ar[citation needed]. Fluorides range from severe toxins such as sarin to life-saving pharmaceuticals such as efavirenz and from refractory materials such as calcium fluoride to highly reactive sulfur tetrafluoride.

Alright, now that we’ve got all that out of the way, let’s take a quick stroll through the history of it.

1909 - Colorado Springs dentist Frederic K. McKay asks the US dental community to help him find an explanation for the “Colorado brown stain,” or “Texas Teeth,” a discoloring of teeth common to the Pikes Peak area. Though residents’ teeth are mottled and discolored, they have far fewer cavities than typical, which is cause for question.

1927 - A dentist in Bauxite, AR, reports extensive staining of residents’ teeth. The town gets its water from a deep well near the site of an aluminum mine; fluoride is a waste by-product of aluminum mining, but the answer isn’t quite clear just yet.

1931 – Using a new analysis on the Bauxite well water, a chemist finds high concentrations of the naturally occurring substance fluoride. McKay hears about the test and sends water samples from other cities. McKay and others eventually determine that fluoride causes the staining but none speak out yet about the prevention of tooth decay.

1939 - Researcher Gerald J. Cox at the Mellon Institute in Pittsburgh releases results from a rat study (showing healthier teeth) to support his recommendation that water be fluoridated.

1942 - The National Institutes of Health publishes a study of 7,000 children which shows that fluoride at 1 part per million in water is enough to minimize tooth decay without causing discoloration (or dental fluorosis, as it’s now called.)

1945 - Federal scientists choose four pairs of cities for a 13- to 15-year study of fluoridation: Grand Rapids and Muskegon, MI; Newburgh and Kingston, NY; Evanston and Oak Park, IL; and Brantford and Sarnia, Ontario. Grand Rapids becomes the first city in the world to have fluoridated water.

1951 - Muskegon, the comparison city for Grand Rapids, begins fluoridating its own water supply. Communities across the country join in, well in advance of any published results of the four-cities studies.

1955 - Procter & Gamble introduces Crest, the first fluoride toothpaste endorsed by the American Dental Association.

1990 - As part of its “Healthy People 2000″ plan, the CDC sets a goal of getting fluoridated water to 75% of Americans. Then, as now, roughly two-thirds have treated water.

Whether you live in a fluoridated water area or not, the evidence is pretty, well, evident. Fluoride will harden enamel and prevent tooth decay in modest doses. If the dosage becomes too high, the worst possibility is that a patient may need to consider a switch to a tooth-whitening formula of toothpaste.

Regardless of your age, you should ask your dentist about the benefits of a fluoride treatment. Who knows, the tooth you save my just be your own.