Hydroxyapatite toothpaste is a fluoride-free option with some research supporting its effectiveness.
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How you brush your teeth – and what you use to do it – is important.
Recently, dentist Dr. Jin-Ho Phark said he noticed patients asking him about fluoride-free toothpaste options. Phark is an associate professor of clinical dentistry at the Herman Ostrow School of Dentistry at the University of Southern California.
“There’s a lot of interest from patients,” Phark says. “I hear this regularly from students too.”
One product in particular demand among patients is a calcium phosphate mineral called hydroxyapatite. Many patients, Phark says, may have seen the products on social media, “being pushed pretty heavily by influencers and other people.”
Traditional fluoride toothpaste became common in the late 1950s, according to the Centers for Disease Control and Prevention, when Procter & Gamble Co. launched Crest nationally. Over the following decades, oral care products containing fluoride as an active ingredient became widely available throughout the world. These products help protect the outer layer of teeth from cavity-causing bacteria.
And dental health is important because it is linked to many systems in your body, from your heart to digestion.
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“There are connections between your oral health and the microbes you have in your mouth, and the systemic health and even the makeup of your gut microbiome,” says Dr. Livia Tenuta, a dentist specializing in tooth decay prevention and associate professor at the University of Michigan School of Dentistry.
The complaint
The promise of hydroxyapatite? Lots of things you care about when it comes to toothpaste: cavity protection, whitening, enamel strengthening. But without fluoride.
Health experts widely agree that fluoride – a natural mineral – is beneficial to your health. But curiosity is growing about fluoride-free options.
“More and more people are refusing fluoride altogether or are hesitant to take it, especially for their children,” says Bennett Amaechi, professor of dentistry at the University of Texas at San Antonio.
This hesitation stems from a history of skepticism about fluoride. Health Secretary Robert F. Kennedy Jr. has blamed water fluoridation for a number of health problems, including arthritis, bone fractures, bone cancer, IQ loss, neurodevelopmental disorders and thyroid disease.
Low levels of fluoride are generally considered safe and essential for preventing cavities. Amaechi says there is no concrete evidence of fluoride’s potential harms when it comes to children’s IQ. And the research that found associations between fluoride and IQ looked at very high levels of fluoride, more than double what is recommended in the U.S. water supply. The CDC previously named the addition of fluoride to public drinking water as one of the 10 greatest public health achievements of the 20th century, alongside immunization and family planning. They also claim that fluoride in water reduces cavities by 25%.
Yet Kennedy’s criticism of fluoride appears to have affected toothpaste and opened up space for products that use hydroxyapatite instead.
So, what is hydroxyapatite?
The hype around hydroxyapatite is partly due to its similarity to tooth enamel. Some research also suggests that hydroxyapatite may help with tooth sensitivity.
Tooth enamel is mainly composed of calcium and phosphate. These minerals form the outer layer of your teeth, which protects the inner layers of tissues, nerves and blood vessels from damage.
Your enamel is stronger than your bones, but it’s still susceptible to damage over time from things like sugary foods and plaque. Bacteria in your mouth feed on sugars and produce acids that eat away at the outer layer of your teeth. Tenuta says that over time, this process sets the stage for tooth decay, often called cavities, or possibly caries (a hole in a tooth that comes from that decay).
She says fluoride toothpaste helps protect teeth by “remineralizing” them with calcium and phosphate.
“When (fluoride is) available in our saliva, in plaque that we haven’t brushed very well, the fluoride that’s left after brushing with the fluoridated toothpaste will actually bring minerals back to the tooth,” Tenuta says.
Fluoride works with these minerals to form a new compound that protects teeth. It acts as a shield for your enamel. But you should regularly brush your teeth with fluoridated toothpaste. Dentists recommend keeping these minerals in our mouth twice a day.
Hydroxyapatite is thought to work in a slightly different way. These products seem to penetrate tiny crevices in tooth enamel.
Many hydroxyapatite products use a form called nano-hydroxyapatite, which contains smaller particles that, in theory, can penetrate enamel pores more easily, although research data is limited.
The proof
Amaechi, who studies the use of hydroxyapatite, says fluoride is being extensively researched, especially in long-term studies. But he says early research on hydroxyapatite is positive.
“When it comes to remineralization and cavity prevention, it’s as effective as fluoride,” says Amaechi.
Amaechi was the author of a 2021 study in the journal Scientific reports, that followed 177 children for almost a year and compared hydroxyapatite toothpaste to fluoride toothpaste. The researchers tracked tooth decay in each group and found that the two groups had similar results. This study included funding from the Dr. Wolff Group, a German company that owns two brands making hydroxyapatite toothpastes.
This company helped finance another study, published two years later in the journal Frontiers of public health. Researchers found similar results after following 171 adults, comparing tooth decay in participants using hydroxyapatite toothpaste to those using fluoride toothpaste for 18 months. Both groups showed similar results, suggesting that hydroxyapatite worked as well as fluoride in the study. However, the study participants were mostly healthy young adults without serious oral health problems.
Tenuta says she would like to see more long-term studies, especially in people at high risk of tooth decay.
“There are very few studies, and they recruited participants with a low risk of cavities,” she says.
A shorter-term study in 2019, published in the Journal of Investigative and Clinical Dentistry, compared hydroxyapatite toothpaste to fluoride toothpaste in 133 people at higher risk of decay. After just over five months, researchers found that both toothpastes worked similarly.
The essentials
Toothpastes with hydroxyapatite tend to be more expensive than those with fluoride – some more than a dollar per ounce.
For patients open to both options, “I would advise them to use fluoride because there is more evidence that it works,” Amaechi says.
Tenuta agrees.
“I would recommend as a better option to stick with a fluoride toothpaste, because that’s what we have a lot of evidence for,” she says.
The American Dental Association, a professional group for dentists, said in an email to NPR that it recognizes that more people are using products containing forms of hydroxyapatite and that some evidence suggests these products may help with remineralization.
However, research on the ingredient is new, “and evidence regarding its clinical effectiveness remains limited and ambiguous, particularly with respect to clinical indications,” wrote ADA Consumer Advisor spokesperson Dr. Ada Cooper.
Instead, the ADA recommends brushing your teeth twice a day for two minutes with fluoride toothpaste, flossing daily, and seeing a dentist regularly.
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