Fluoride has been an essential part of dental hygiene for more than 60 years, since the U.S. Public Health Service first became aware of its health benefits—namely, preventing or even reversing tooth decay by strengthening enamel. It has even been championed by the Centers for Disease Control as “one of the 10 greatest achievements in public health in the 20th century.”

What many people don’t realize, however, is that their toothpaste or mouthwash isn’t their only daily source of fluoride; these days, 75 percent of fluoride intake in the United States comes from water, soft drinks, and juice, according to the American Dental Hygienists’ Association (ADHA). In the 40s and 50s, public water supplies were most Americans’ first source for the cavity-fighting compound. It was only after the noted success of water fluoridation in combating tooth decay that active-ingredient sodium fluoride toothpastes, mouthwashes, dietary supplements, and prescription gels and foams were introduced.

Like most other things in life, though, fluoride is most beneficial in moderation. So the question becomes, What happens when consumers augment their already satisfactory consumption of fluoride? When does enough become too much? And what are the alternatives?

According to the Centers for Disease Control, 32 percent of American children are now affected by dental fluorosis, an irreversible condition whose cause is usually the overconsumption of fluoride-containing dental products. This number is up from 10 percent in the 40s. Fluorosis is caused by damage to children’s enamel-forming cells and is characterized by a chalklike discoloration, or milky white spots, on children’s enamel.

Though it is not known to have any negative internal health effects, some people argue that fluorosis may have disturbing implications. According to the Environmental Working Group, a nonprofit environmental research association based in Washington, , children’s teeth are similar to their bones—alive and growing. So, if fluoride can rearrange the “crystalline structure of a tooth’s enamel as it is still growing,” according to the group, what potential harm may be occurring throughout the rest of the bones?

A recent review from the US National Research Council supports that there may be some, albeit low, credibility to this concern. According to the review, high doses of fluoride may weaken bone strength, reduce thyroid function, and cause bone cancer in adolescent boys. Still, more than 100 national and international health-service agencies, such as the ADHA, remain supportive of fluoride’s dental health benefits.

So what’s the happy medium? How can one benefit from the proven cavity-fighting properties of fluoride without risking fluorosis or other potential negative effects of overconsumption?

As with the majority of health concerns, a healthy diet—particularly one low in sugar—is the first step toward stellar dental health. The next is to brush and floss regularly. A host of alternative toothpastes and mouthwashes are now available for people opting for a fluoride-free dental-hygiene regimen.

Parents, you should be aware of all sources of fluoride in your child’s daily routine. The American Dental Association recommends fluoride-free water for infants, and the California Dental Association advises that children who live in communities with fluoridated water should not consume fluoride tablets or vitamins. Parents should also monitor their children’s brushing habits, ensuring that they do not swallow any toothpaste, accidentally or otherwise; after all, new flavors can be quite tempting for little ones!

Most important, consumers should remain educated in order to make the healthiest choices for their particular lifestyle.

—Katie Gutierrez