In the wooded highlands of northern Arkansas, where small towns have few dentists, water officials who serve more than 20,000 people have for more than a decade openly defied state law by refusing to add fluoride to the drinking water.

For its refusal, the Ozark Mountain Regional Public Water Authority has received hundreds of state fines amounting to about $130,000, which are stuffed in a cardboard box and left unpaid, said Andy Anderson, who is opposed to fluoridation and has led the water system for nearly two decades.

This Ozark region is among hundreds of rural American communities that face a one-two punch to oral health: a dire shortage of dentists and a lack of fluoridated drinking water, which is widely viewed among dentists as one of the most effective tools to prevent tooth decay. But as the anti-fluoride movement builds unprecedented momentum, it may turn out that the Ozarks were not behind the times after all.

“We will eventually win,” Anderson said. “We will be vindicated.”

Fluoride, a naturally occurring mineral, keeps teeth strong when added to drinking water, according to the Centers for Disease Control and Prevention and the American Dental Association. But the anti-fluoride movement has been energized since a government report last summer found a possible link between lower IQ in children and consuming amounts of fluoride that are higher than what is recommended in American drinking water. Dozens of communities have decided to stop fluoridating in recent months, and state officials in Florida and Texas have urged their water systems to do the same. Utah is poised to become the first state to ban it in tap water.

Health and Human Services Secretary Robert F. Kennedy Jr., who has long espoused fringe health theories, has called fluoride an “industrial waste” and “dangerous neurotoxin” and said the Trump administration will recommend it be removed from all public drinking water.

Separately, Republican efforts to extend tax cuts and shrink federal spending may squeeze Medicaid, which could deepen existing shortages of dentists in rural areas where many residents depend on the federal insurance program for whatever dental care they can find.

Dental experts warn that the simultaneous erosion of Medicaid and fluoridation could exacerbate a crisis of rural oral health and reverse decades of progress against tooth decay, particularly for children and those who rarely see a dentist.

“If you have folks with little access to professional care and no access to water fluoridation,” said Steven Levy, a dentist and leading fluoride researcher at the University of Iowa, “then they are missing two of the big pillars of how to keep healthy for a lifetime.”

Many already are.

Overlapping ‘Dental Deserts’ and Fluoride-Free Zones

Nearly 25 million Americans live in areas without enough dentists — more than twice as many as prior estimates by the federal government — according to a recent study from Harvard University that measured U.S. “dental deserts” with more depth and precision than before.

Hawazin Elani, a Harvard dentist and epidemiologist who co-authored the study, found that many shortage areas are rural and poor, and depend heavily on Medicaid. But many dentists do not accept Medicaid because payments can be low, Elani said.

The ADA has estimated that only a third of dentists treat patients on Medicaid.

“I suspect this situation is much worse for Medicaid beneficiaries,” Elani said. “If you have Medicaid and your nearest dentists do not accept it, then you will likely have to go to the third, or fourth, or the fifth.”

The Harvard study identified over 780 counties where more than half of the residents live in a shortage area. Of those counties, at least 230 also have mostly or completely unfluoridated public drinking water, according to a KFF analysis of fluoride data published by the CDC. That means people in these areas who can’t find a dentist also do not get protection for their teeth from their tap water.

The KFF Health News analysis does not cover the entire nation because it does not include private wells and 13 states do not submit fluoride data to the CDC. But among those that do, most counties with a shortage of dentists and unfluoridated water are in the south-central U.S., in a cluster that stretches from Texas to the Florida Panhandle and up into Kansas, Missouri, and Oklahoma.

In the center of that cluster is the Ozark Mountain Regional Public Water Authority, which serves the Arkansas counties of Boone, Marion, Newton, and Searcy. It has refused to add fluoride ever since Arkansas enacted a statewide mandate in 2011. After weekly fines began in 2016, the water system unsuccessfully challenged the fluoride mandate in state court, then lost again on appeal.

Anderson, who has chaired the water system’s board since 2007, said he would like to challenge the fluoride mandate in court again and would argue the case himself if necessary. In a phone interview, Anderson said he believes that fluoride can hamper the brain and body to the point of making people “get fat and lazy.”

“So if you go out in the streets these days, walk down the streets, you’ll see lots of fat people wearing their pajamas out in public,” he said.

Nearby in the tiny, no-stoplight community of Leslie, Arkansas, which gets water from the Ozark system, the only dentist in town operates out of a one-man clinic tucked in the back of an antique store. Hand-painted lettering on the store window advertises a “pretty good dentist.”

James Flanagin, a third-generation dentist who opened this clinic three years ago, said he was drawn to Leslie by the quaint charms and friendly smiles of small-town life. But those same smiles also reveal the unmistakable consequences of refusing to fluoridate, he said.

“There is no doubt that there is more dental decay here than there would otherwise be,” he said. “You are going to have more decay if your water is not fluoridated. That’s just a fact.”

Fluoride Seen as a Great Public Health Achievement

Fluoride was first added to public water in an American city in 1945 and spread to half of the U.S. population by 1980, according to the CDC. Because of “the dramatic decline” in cavities that followed, in 1999 the CDC dubbed fluoridation as one of 10 great public health achievements of the 20th century.

Currently more than 70% of the U.S. population on public water systems get fluoridated water, with a recommended concentration of 0.7 milligrams per liter, or about three drops in a 55-gallon barrel, according to the CDC.

Fluoride is also present in modern toothpaste, mouthwash, dental varnish, and some food and drinks — like raisins, potatoes, oatmeal, coffee, and black tea. But several dental experts said these products do not reliably reach as many low-income families as drinking water, which has an additional benefit over toothpaste of strengthening children’s teeth from within as they grow.

Two recent polls have found that the largest share of Americans support fluoridation, but a sizable minority does not. Polls from Axios/Ipsos and AP-NORC found that 48% and 40% of respondents wanted to keep fluoride in public water supplies, while 29% and 26% supported its removal.

Chelsea Fosse, an expert on oral health policy at the American Academy of Pediatric Dentistry, said she worried that misguided fears of fluoride would cause many people to stop using fluoridated toothpaste and varnish just as Medicaid cuts made it harder to see a dentist.

The combination, she said, could be “devastating.”

“It will be visibly apparent what this does to the prevalence of tooth decay,” Fosse said. “If we get rid of water fluoridation, if we make Medicaid cuts, and if we don’t support providers in locating and serving the highest-need populations, I truly don’t know what we will do.”

Multiple peer-reviewed studies have shown what ending water fluoridation could look like. In the past few years, studies of cities in Alaska and Canada have shown that communities that stopped fluoridation saw significant increases in children’s cavities when compared with similar cities that did not. A 2024 study from Israel reported a “two-fold increase” in dental treatments for kids within five years after the country stopped fluoridating in 2014.

Despite the benefits of fluoridation, it has been fiercely opposed by some since its inception, said Catherine Hayes, a Harvard dental expert who advises the American Dental Association on fluoride and has studied its use for three decades.

Fluoridation was initially smeared as a communist plot against America, Hayes said, and then later fears arose of possible links to cancer, which were refuted through extensive scientific research. In the ’80s, hysteria fueled fears of fluoride causing AIDS, which was “ludicrous,” Hayes said.

More recently, the anti-fluoride movement seized on international research that suggests high levels of fluoride can hinder children’s brain development and has been boosted by high-profile legal and political victories.

Last August, a hotly debated report from the National Institutes of Health’s National Toxicology Program found “with moderate confidence” that exposure to levels of fluoride that are higher than what is present in American drinking water is associated with lower IQ in children. The report was based on an analysis of 74 studies conducted in other countries, most of which were considered “low quality” and involved exposure of at least 1.5 milligrams of fluoride per liter of water — or more than twice the U.S. recommendation — according to the program.

The following month, in a long-simmering lawsuit filed by fluoride opponents, a federal judge in California said the possible link between fluoride and lowered IQ was too risky to ignore, then ordered the federal Environmental Protection Agency to take nonspecified steps to lower that risk. The EPA started to appeal this ruling in the final days of the Biden administration, but the Trump administration could reverse course.

The EPA and Department of Justice declined to comment. The White House and Department of Health and Human Services did not respond to questions about fluoride.

Despite the National Toxicology Program’s report, Hayes said, no association has been shown to date between lowered IQ and the amount of fluoride actually present in most Americans’ water. The court ruling may prompt additional research conducted in the U.S., Hayes said, which she hoped would finally put the campaign against fluoride to rest.

“It’s one of the great mysteries of my career, what sustains it,” Hayes said. “What concerns me is that there’s some belief amongst some members of the public — and some of our policymakers — that there is some truth to this.”

Not all experts were so dismissive of the toxicology program’s report. Bruce Lanphear, a children’s health researcher at Simon Fraser University in British Columbia, published an editorial in January that said the findings should prompt health organizations “to reassess the risks and benefits of fluoride, particularly for pregnant women and infants.”

“The people who are proposing fluoridation need to now prove it’s safe,” Lanphear told NPR in January. “What the study does, or should do, is shift the burden of proof.”

Cities and States Rethink Fluoride

At least 14 states so far this year have considered or are considering bills that would lift fluoride mandates or prohibit fluoride in drinking water altogether. In February, Utah lawmakers passed the nation’s first ban, which Republican Gov. Spencer Cox told ABC4 Utah he intends to sign. And both Florida Surgeon General Joseph Ladapo and Texas Agriculture Commissioner Sid Miller have called for their respective states to end fluoridation.

“I don’t want Big Brother telling me what to do,” Miller told The Dallas Morning News in February. “Government has forced this on us for too long.”

Additionally, dozens of cities and counties have decided to stop fluoridation in the past six months — including at least 16 communities in Florida with a combined population of more than 1.6 million — according to news reports and the Fluoride Action Network, an anti-fluoride group.

Stuart Cooper, executive director of that group, said the movement’s unprecedented momentum would be further supercharged if Kennedy and the Trump administration follow through on a recommendation against fluoride.

Cooper predicted that most U.S. communities will have stopped fluoridating within years.

“I think what you are seeing in Florida, where every community is falling like dominoes, is going to now happen in the United States,” he said. “I think we’re seeing the absolute end of it.”

If Cooper’s prediction is right, Hayes said, widespread decay would be visible within years. Kids’ teeth will rot in their mouths, she said, even though “we know how to completely prevent it.”

“It’s unnecessary pain and suffering,” Hayes said. “If you go into any children’s hospital across this country, you’ll see a waiting list of kids to get into the operating room to get their teeth fixed because they have severe decay because they haven’t had access to either fluoridated water or other types of fluoride. Unfortunately, that’s just going to get worse.”

Methodology: How We Counted This KFF Health News article identifies communities with an elevated risk of tooth decay by combining data on areas with dentist shortages and unfluoridated drinking water. Our analysis merged Harvard University research on dentist-shortage areas with large datasets on public water systems published by the U.S. Centers for Disease Control and Prevention.The Harvard research determined that nearly 25 million Americans live in dentist-shortage areas that span much of rural America. The CDC data details the populations served and fluoridation status of more than 38,000 public water systems in 37 states. We classified counties as having elevated risk of tooth decay if they met three criteria:More than half of the residents live in a dentist-shortage area identified by Harvard.The number of people receiving unfluoridated water from water systems based in that county amounts to more than half of the county’s population.The number of people receiving unfluoridated water from water systems based in that county amounts to at least half of the total population of all water systems based in that county, even if those systems reached beyond the county borders, which many do.

Our analysis identified approximately 230 counties that meet these criteria, meaning they have both a dire shortage of dentists and largely unfluoridated drinking water.

But this total is certainly an undercount. Thirteen states do not report water system data to the CDC, and the agency data does not include private wells, most of which are unfluoridated.