Dental caries, or cavities, remains a significant health problem in the United States today. Tooth decay is the most common health problem in U.S. children, five times more common than asthma, and children with poor oral health are 3 times more likely to miss school as a result of dental pain. Among adults, dental caries remains a significant health concern. According to the United States, National Health and Nutrition Examination Survey, 1999–2004, 86% of adults ages 20-35 had experienced dental caries, and that number jumps to 95% among the 35 and above age group. In a 2008 study of the armed forces, 52% of new recruits were categorized as Class 3 in “dental readiness” — meaning they had oral health problems that needed urgent attention and would delay overseas deployment. A 2008 study showed that people who were missing teeth were seen as less intelligent and less desirable by employers, damaging job prospects. Emergency department care for dental concerns cost up to $2.1 billion in 2010. Clearly, dental decay can negatively affect the quality of any individual’s life significantly.  However, studies show that utilization of fluoride and fluoridation programs has significantly decreased the incidence of cavities among Americans in the last 100 years. Children who drink fluoridated water as their teeth grow will have stronger teeth that resist decay better over their lifetime. A 2010 study confirmed that the fluoridated water consumed as a young child makes the loss of teeth due to decay less likely 40 or 50 years later. In today’s blog post, we will examine the safety and efficacy of fluoride programs more closely.

What is fluoride and fluoridation?

Fluoride is a mineral, released into the environment naturally in water, air and food sources. Fluorine, from which fluoride is derived, is the 13th most abundant element on Earth. In some areas, through the process of fluoridation, fluoride is supplemented into, or even removed from, a community’s water supply, to achieve the level recommended for optimal dental health. In 2015, the U.S. Centers for Disease Control and Prevention (CDC) examined all the ways the population receives fluoride, including via foods and toothpaste, and recommended that communities fluoridate water at 0.7 parts per million. Any less than that puts the health of our teeth at risk. (One ppm is the equivalent of 1 mg/L, or 1 inch in 16 miles.) Fluoridation also ensures that naturally high levels of fluoride are reduced to safe levels within the water supply. Because fluoride exists naturally in virtually all water supplies, it isn’t a question of choosing whether to utilize it, but a question of assuring that people receive safe levels to maintain health.

Community water fluoridation has been recognized by the CDC as one of 10 great public health achievements of the 20th Century, and fluoridation of community drinking water is a major factor responsible for the decline in dental caries (tooth decay) during the second half of the 20th century. It has found to be one of the most practical, cost-effective, equitable and safe measures a community can take to prevent tooth decay and improve oral health, benefiting individuals of all ages and socioeconomic status.

What does fluoride do for my teeth?

Throughout each day, minerals are lost from our tooth enamel due to exposure to dietary acids, systemic acid, or bacterial plaques. This process is called demineralization. Too much demineralization without enough remineralization to repair the enamel layer leads to dental caries (cavities or decay).   Remineralization occurs when minerals excreted in our saliva, or absorbed from foods and drinks consumed, are then redistributed into our enamel layer. These minerals include fluoride, calcium, and phosphate, among others. Fluoride specifically helps prevent decay by strengthening the mineral bonds in the enamel layer, and by making the tooth more resistant to acid attack, and therefore resistant to caries.

Fluoride also reduces dental cavity development by decreasing the activity of cariogenic (cavity causing) bacteria. It does so by inhibiting the process by which cariogenic bacteria metabolize carbohydrates to produce acid. It also affects bacterial production of adhesive polysaccharides, slowing colonization. In laboratory studies, when a low concentration of fluoride is constantly present, the primary type of cariogenic bacteria, Streptococcus mutans, produces less acid, and therefore less dental damage.

I have heard some disconcerting things about fluoride. How safe is it?

Fluoride has been thoroughly studied, with 3,200 studies published on fluoridation alone, and evidence shows it is safe and effective. Opponents sometimes create the false impression that fluoride comes from fertilizer; rather, much of the fluoride used to fluoridate water is extracted from phosphate rock, that is also used to create fertilizers that will enrich soil. Phosphoric acid (found in many sodas, including Coke and Pepsi) is derived from the same phosphate rock. Fluoride is one of several examples of everyday products fortified to improve our health — iodine is added to salt, folic acid is added to breads and cereals, and Vitamin D is added to milk.

Some studies that have been used to claim that fluoride is linked to lower IQ scores in children, or other health concerns, involved fluoride levels that were two to five times the level used to fluoridate drinking water in the U.S. Researchers who evaluated these studies from “basic errors,” along with the possibility that the lower IQs could be traced to other factors, such as arsenic exposure, the burning coal inside homes and the eating of contaminated grain. Upon evaluation, researchers also found that many other studies were poorly designed, gathered unreliable data, and were not peer-reviewed by independent scientists. Regarding some reports, the CDC and National Research Council (NRC) stated, “The report addresses the safety of high levels of fluoride in water that occur naturally, and does not question the use of lower levels of fluoride to prevent tooth decay.”  It is always important to consider the sources of information, and rely on reliable, peer-reviewed research.

I have heard there is no water fluoridation in Europe. Why is this?

A common misconception is that water fluoridation is not widely used in Europe for safety reasons. Actually, Europe benefits from many fluoridation programs. Fluoridated water reaches 12 million Europeans, mostly residents of Great Britain, Ireland and Spain. In many areas of Europe, water fluoridation systems are logistically difficult because of the terrain and because there are tens of thousands of separate sources for drinking water. Instead, salt fluoridation is the most widely used approach in Europe. In fact, at least 70 million Europeans consume fluoridated salt.  This method of fluoridation reaches most of the population in Germany and Switzerland, where there are some of the lowest rates of tooth decay in all of Europe. Fluoridated milk programs reach millions more people, mostly in Eastern Europe.  Finally, other regions utilize fluoride rinse to maintain fluoride availability to the public.

While it may remain a controversial subject, valid research still points to the fact that utilization of this naturally occurring mineral remains one of the most effective ways of preventing cavity development, and the related health risks associated with dental decay. Fluoride is widely available in fluoridated water, toothpaste, rinses, supplements, and prescription applications.  Ask your hygienist about your unique fluoride recommendations today!

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–Alexa, your friendly neighborhood hygienist!