Brown Teeth Have Fewer Cavities

Effective fluoride treatment for cavities began with brown teeth in western towns.

Unless you are reading this article surrounded by pro hockey players, it’s likely that everyone within 50 ft of you has their own teeth. This may seem self-evident, but 100 years ago, before fluoride treatments and fluoride toothpaste, you would meet people every day who were missing many or most of their teeth.

Even the most dignified people suffered from toothless grins. George Washington led the colonial armies to victory and helped found the U.S. while wearing wooden dentures. Before Washington was fitted with his carved chewers, he suffered up to 32 extractions without anesthetic. Perhaps this was part of what made him tough enough to lead an army.

While most people still dread visits to the dentist, they are likely to call for an appointment at the first sign of pain. In fact, most people expect to leave the dentist’s office with the same number of teeth they had on arrival — an expectation more common in the latter half of the 20th century than at any other time in history. We owe a debt of gratitude for our dental prosperity to a single element — fluoride.

So how did fluoride and teeth first come together? Fluoride research began in 1901, when a young dentist named Frederick McKay opened a dental office in Colorado Springs, CO. When he arrived, McKay was astounded to find scores of Colorado Springs natives with brown stains on their teeth. The unsightly stains, which could be as dark as chocolate candy, were permanent. McKay found no mention of brown-stained teeth in any of the dental literature of the day, nor did he find useful information from other dentists in the area. Although brown teeth were unattractive, they were also sturdy. People with brown teeth had fewer cavities.

Through sheer perseverance, McKay convinced a leading dental researcher to visit Colorado Springs. Through systematic investigation, McKay and his collaborators found that Colorado Brown Stain occurred in 90% of native-born children, but that adults who moved to the area were unaffected. As McKay’s findings became known, he collaborated with dentists in Idaho and Arkansas who noted the same problem in their communities. Despite their efforts, the answer to the puzzle remained hidden for 30 years.

In 1931 an Alcoa chemist familiar with McKay’s findings examined the water from several towns affected by brown stain using photo spectrographic analysis. The one thing the samples had in common was a high level of fluoride. Fluoride moved quickly from curiosity to national prominence. In the mid 1930s, the Public Health Service commissioned a national survey of fluoride in drinking water. The survey found that communities with fluoride levels of 1.0 ppm had fewer cavities and white teeth. Brown stain, now known formally as fluorosis, occurred in communities with fluoride levels above 2–3 ppm.

In 1945 fluoride had its first public trial in Grand Rapids, MI. The result of the 15-year study: 60% fewer cavities and white teeth. With long-term data proving the value of fluoridation, communities across the country began treating local water supplies, giving the generation that followed the baby boomers stronger, more cavity-resistant teeth.

In a parallel development, Harry G. Day of Indiana University studied fluoridation with the goal of making a practical fluoride treatment that could be added to toothpaste. Day set up a close cooperation between Procter and Gamble and the university. P&G funded the research. In return, they received detailed reports on Day’s findings. P&G also promised to make the Indiana University Research Foundation the major beneficiary of proceeds from successful patents.

In 1955 the Food and Drug Administration (FDA) approved stannous fluoride for use in toothpaste. P&G called their new ingredient fluoristan and introduced Crest toothpaste, the new brand with fluoristan. Crest was an instant success and gave P&G its largest single- year sales increase in history.

The National Institute of Dental Health calls fluoride treatment one of the great preventive health measures of the 20th century, making tooth decay preventable for the first time in history. Who would have thought the beautiful smiles we see every day began with brown teeth in Colorado Springs?

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This article was originally published under the title "We're History" in the February 2003 edition of Chemical Engineering Progress magazine. This article was prepared by Neil Gussman, communications manager for the Chemical Heritage Foundation.