The Mystery of Colorado Brown Stain: How Two Men Changed Dental Care Forever

As most of Monroe WA dentist Dr. Crandall’s patients already know, fluoride plays an important role in helping to protect the health of their teeth and gums.

Tooth decay occurs when the outer surface of a tooth – called enamel – is attacked by acid produced by bacteria living in the mouth referred to as plaque. Whenever you consume foods or drinks that contain sugar, plaque quickly begins to transform sugar into acid. Plaque can even hold the acid it produces in contact with the surface of your teeth for hours before the saliva in the mouth can wash it away.

During the time plaque acids stay on the surface of your teeth, it begins to leach away valuable minerals from enamel in a process known as demineralization. Fortunately, once plaque acids have been neutralized the minerals can return to the surface of your teeth in a process known as remineralization.

Fluoride helps protect your teeth by encouraging the remineralization process, and by strengthening your tooth enamel. In other words, fluoride helps your teeth become stronger and more resistant to plaque acids, thereby reducing your risk of developing tooth decay and cavities.

The use of fluoride has been so successful at preventing tooth decay that some researchers estimate a 40 percent reduction of cavities in U.S. children since the mineral was first used in preventative dentistry.

But how did health experts first discover what effects fluoride had on teeth? That story begins with a mystery that would take 30 years to solve.

A Strange Occurrence

The research into fluoride first began shortly after the turn of the century when a young dental school graduate named Frederick McKay moved to Colorado Springs in 1901. After opening his practice, Dr. McKay was confounded by the number of patients that arrived at his office with noticeably brown stains on their teeth. In some extreme cases, a patient’s teeth would be so severely stained that looked the color of chocolate candy.

Alarmed by what he considered a serious epidemic, Dr. McKay scoured the latest dental literature at the time looking for some explanation to the town’s problem. However, despite his effort, Dr. McKay found no mention of any condition that would explain what was happening to the people of Colorado Springs.

To locals, the cause of their condition was attributed to a variety of bizarre factors that ranged from diets too high in pork, to drinking milk of inferior quality, to a water supply that contained excessive levels of calcium.

Dr. McKay’s initial investigation into the cause of what had become known as “Colorado Brown Stain” was met with indifference from other area dentists who considered the issue unimportant, a testament to how comfortable people can become with even the strangest occurrences if seen daily.

Not dissuaded, Dr. McKay continued his independent research, and received his first major breakthrough in 1909.

A Memorable Partnership

Despite the lack of interest by local dentists to solve the mystery of Colorado Brown Stain, Dr. McKay was able to pique the interest of renowned dental researcher G.V. Black, and convinced the doctor to visit Colorado Spring in 1909. Dr. Black, who initially dismissed the condition because he thought it impossible that such a pronounced dental epidemic could go unnoticed by academics, was eventually convinced to visit the town after a survey conducted by Colorado Sprints Dental Society found that 90 percent of locally born children suffered from tooth staining.

After arriving in Colorado Springs, Dr. Black was struck by how widespread the staining was among the native population, and would often walk the city streets talking to children so he could gauge the various stages of the condition. So taken was Dr. Black with this mystery that he dedicated the rest of his life studying the phenomenon until his death in 1915.

The collaboration between Drs. Black and McKay yielded two major breakthroughs. First, they determined the condition was the result of developmental imperfections in the children’s teeth. This meant that adults with healthy permanent teeth didn’t need to worry about developing brown stains, but kids still waiting to develop their permanent teeth were at high risk. Second, and most surprising, the doctors found that teeth affected by Colorado Brown Strain were remarkably resilient against the affects of tooth decay.

It was at this stage of his investigation that Dr. McKay first began to suspect that the locals may have been on to something when suggesting water contamination was behind the epidemic. This suspicion was later reinforced in 1923 when the small town of Oakley, Idaho reported the appearance of brown stains on children’s teeth.

Traveling to the city, Dr. McKay discovered the town had recently constructed a new communal water pipeline from a nearby hot spring. Despite finding no trace of contaminants after testing the water, Dr. McKay recommended the town find an alternative source for their drinking water. Several years later, children whose baby teeth had been stained were starting to develop healthy, stain-free permanent teeth.

Despite feeling certain that something in the water supplies of both towns was behind the cause of these brown stains, Dr. McKay was left without an answer until 1931.

The Answer Revealed

Several years later, reports of brown stains on children’s teeth were reported in the small aluminum mining town of Bauxite, Arkansas. Traveling to the town to investigate, Dr. McKay discovered that while brown stains were present on the teeth of children in Bauxite, the condition as absent in a nearby town only five miles away.

Once again, tests on the local water supply provided no answers about what could be the source of the contamination. However, in a fortuitous step, Dr. McKay published the results of his findings on Bauxite with the help of officials from the United States Public Health Service. This report made its way to the desk of the Aluminum Company of America’s – the company that owned the aluminum mines in Bauxite – head scientist.

Concerned this report would fuel sentiments against the safety of aluminum, researchers at the ACA tested water samples Bauxite for potential contaminants. Using the most scientifically advanced equipment available at the time – far more advanced than what Dr. McKay had at his disposal – researchers at the ACA found the water supply in Bauxite contained extremely high levels of fluoride. In a letter to Dr. McKay explaining their results, researchers from ACA compelled Dr. McKay to submit water samples from Colorado Springs, which also tested positive for high levels of fluoride.

After 30 years of searching, Dr. McKay finally had his answer.

Fluorosis is a condition caused by a high level of exposure fluoride during tooth development. By drinking water that contained high levels of fluoride, children in Colorado Springs developed discolored teeth. But, after years of testing, researchers discovered that by reducing the amount of fluoride a child is exposed to, fluorosis could be prevented while still strengthening tooth enamel. That discovery led directly to the widespread use of fluoride by dentists today.