Around the turn of the 20th century, Colorado dentist Dr. Frederick S. McKay noticed many of his patients had something known as dental fluorosis, which causes staining of the teeth.
In milder cases, it may have appeared as white spots, but in some, the stains were brown.
By 1928, McKay noticed those with darker stained teeth also had less tooth decay, leading him to believe it was something in the water. By the early 1930s, it was identified by others as fluoride.
Fluorine, the 13th most abundant of 102 naturally occurring elements, can be found in water, soil and most foods. For that reason, scientists do not consider it harmful to the environment, according to the Indiana State Health Department website.
Elements are the chemical building blocks for everything found in nature, including gases, liquids and solids.
Like most elements, fluorine is not found free in nature and usually is part of compounds made up with other elements. Combined with water, fluorine becomes a fluoride ion.
The health department reported most surface water and groundwater in the state has a natural fluoride concentration of 0.1-0.2 milligrams per liter, far below recommended levels. The U.S. Department of Health and Human Services recommends a level of 0.7 mg/L of fluoride in drinking water to prevent tooth decay and promote good oral health.
In the 1930s, scientists started examining the relationship between fluoride and tooth decay after it was noticed children drinking water high in fluoride had fewer cavities.
Eventually, it was determined that for children younger than 8, fluoride helps strengthen the permanent teeth developing under the gums. For adults, drinking water with fluoride continues to support tooth enamel.
According to the state health department, fluoride prevents tooth decay in three ways: It prevents plaque bacteria from producing acid; it is absorbed into the tooth enamel, preventing the acids from entering; and it remineralizes teeth after attacks by acid-producing bacteria.
In 1945, the city of Grand Rapids, Michigan, became the first to add fluoride to city water. The first three Indiana communities to fluoridate their water supplies were Fort Wayne, Indianapolis and Huntingburg, all in 1951.
One of three chemicals usually are used to fluoridate water in the United States: sodium fluoride, sodium fluorosilicate or fluorosilicic acid, which is a byproduct of the production of fertilizer.
About 4.3 million Hoosiers consume fluoridated water through nearly 300 public water supplies and 33 rural schools, the state health department reported. An additional 100,000 Hoosiers have access to optimally fluoridated water through private wells.
Alexandria, Ingalls and Orestes, which gets its water from Alexandria, are among 84 Indiana communities that do not fluoridate, the state health department reported.
Evaluating studies
Though anyone can read a study, Alexandria City Council Member Dr. David Steele, Alexandria dentist Dr. Michael Kluth and officials at the Indiana Department of Health have argued the average consumer likely doesn’t have the knowledge or background to understand whether its results are valid.
For instance, many people will mistake correlation for causation, but just because something is present when something else happens doesn’t mean it is the cause. There may be other variables that are the real influence of the outcome.
A variety of organizations offer the following guidelines for evaluating the credibility of a study:
• Follow the money. Who stands to gain from a particular study result? Studies can be funded by the government, foundations and activists, and industries. Any can have an agenda.
• Is the process used transparent? The credibility of a study is only as good as the integrity and accountability of authors, editors and reviewers. The competitive nature and other pressures of science may, on occasion, lead a researcher astray.
• Has it been peer-reviewed? Most studies are published only after their design and findings have been verified by other experts in the field. The peer-review process helps identify flaws in the design, presentation, analysis and interpretation of studies and provides.
• Has anyone disagreed with the study or its findings? Almost any study will have its critics. But what matters are the credentials of the critics. Are they people in the same field? Do they have a Ph.D or just a bachelor’s degree?
• How was the study designed? The best studies are “double-blind,” meaning the researchers don’t know which subjects are in the control set.
• Has the study been replicated, and was the outcome similar? Every legitimate outcome should be able to be reproduced by someone else under similar conditions. It’s extremely rare for a single study offering an alternative conclusion to be proven valid.