As an endodontist who specializes in saving natural teeth, I have a front-row seat when it comes to observing the nuances of oral health. I can tell who is a flosser, a fan of tooth whiteners, and the sweet tooths among us. Occasionally, and particularly in younger adults, I see signs of severe tooth decay. That usually means one thing—they have lived in a town that lacks fluoride in their water supply.

These days, it seems like you cannot turn on the news without hearing something about fluoride. Somehow, fluoride went from a no-brainer that the CDC has long touted as one of the 10 greatest health achievements of the 20th century to a potential villain, responsible for robbing points off kids’ IQ scores, affecting thyroid levels, and altering the gut microbiome—all based on incomplete information and a misinterpretation of studies or studies done in other countries where fluoride is uncontrolled and exposure is significantly higher than in the U.S.

As more states across the country start pulling fluoride from their population’s water supply, endodontists and other dental professionals agree that it is time to sound the alarm on the implications of this catastrophic threat to our nation’s oral health. For me to try to convince you why fluoride in water is essential, it is important to understand what it is, who it benefits (hint: everyone!), and what the scientific data tell us.

A dental diamond in the rough

While fluoride in the water supply is crucial for maintaining good oral health, to fully appreciate its significance, we need to look first at what it does and how it works. Fluoride is a naturally occurring mineral found in water, soil, air, and some foods. However, most frequently, the naturally occurring concentration of fluoride is not high enough to have a positive impact on tooth development.

When added to the water supply in appropriate, controlled amounts, fluoride is used to prevent tooth decay by strengthening enamel and making it less susceptible to the acids that cause decay. This dental powerhouse also has the ability to remineralize enamel, leading to a self-repair of tooth structure and is most helpful during tooth development—which occurs before most teeth erupt (between birth and age 6). But fluoride’s remineralization effects are far-reaching, benefiting all age groups.

Back in 1945, Grand Rapids, Michigan, became the first city in the world to intentionally add fluoride to drinking water. Within 10 years, studies on Grand Rapids’ children showed a 50–60 percent reduction in tooth decay when compared to other non-fluoridated cities. Today, more than two-thirds of the U.S. population receives fluoride through drinking water. The current trend of reducing the number of Americans with access to fluoride in drinking water will only land more patients in the dental chair of myself and my fellow endodontists who routinely perform root canals (a proven procedure to save natural teeth) to alleviate severe dental pain, often due to tooth decay that adequate levels of fluoride could have helped prevent.

Lower income, underserved communities stand to lose most.

Although removing fluoride from the water system will affect all of us and particularly children, it will have the greatest impact on the lower income, underserved communities. Fluoride does not discriminate. Providing fluoride in water reaches everyone in a community regardless of income, education, or access to dental care. Quite simply, fluoride is one of the most equitable public health measures we have, improving oral health across generations. Lower income families and families that lack access to care will find themselves in a more difficult situation as mounting costs will make dentistry unaffordable.

Ultimately, this will lead to tooth loss. Teeth that develop without fluoride are softer and weaker than teeth that do. This leads to more decay, more extensive dental work, and ultimately more tooth loss. Fifty years ago, before water fluoridation, our grandparents wore dentures due, in large part, to a lack of dental care and the costs of access to care being prohibitive. If they had a cavity or pain, they had their tooth extracted rather than the tooth-preserving root canal procedure that is preferred today. But even now in rural America, where fluoridated water is unavailable and/or care is unaffordable, it is not unusual to find people in their 30s and 40s with missing teeth.

A costly gamble with no winners

The risks of removing fluoride from our drinking water are significant and run much deeper than even our children having more tooth decay. While more tooth decay leads to more dental appointments and greater costs, it also results in more missed work and school. Additionally, it leads to more extensive dentistry needs and, in the long term, can lead to tooth loss. Replacing a lost tooth requires a substantial investment in time and money. The most effective means for patients to retain their natural teeth is to protect and preserve them.

Our underserved populations—where patients already experience difficulty receiving treatment—will have even less access to dental care, but a greater need. Even our neighbors in cities like Calgary, Canada, have opted to return fluoride to the water systems after removing it for just these reasons. Cities in Alaska that removed fluoride from their water systems also showed increases in decay, leading to at least one more required dental visit and increased costs of more than $300 per year, per person.

In my practice in Cleveland, it is not unusual to see children who grow up and develop with well water that does not contain fluoride. To no surprise, their teeth have much more decay, many more extensive fillings, and often require root canal therapy.

When used as directed and in appropriate amounts, fluoride is safe. It has been studied for more than 100 years with no deleterious effects. Children and adults in communities with fluoridated water show between 25–50 percent reduction in cavities, and the ripple effects of a healthier mouth extend to better overall health. Let’s fight to keep fluoride in our drinking water. Our children deserve as much.

Steven J. Katz is an endodontist and president, American Association of Endodontists.