Hydroxyapatite toothpaste: New mineral alternative faces cost and evidence hurdles

Dr. Jin-Ho Phark, an associate professor of clinical dentistry at the University of Southern California, reports a steady increase in patients asking about fluoride-free toothpaste options. He notes that the interest is driven by social media influencers who are aggressively promoting a calcium phosphate mineral called hydroxyapatite. Many consumers have encountered these products online, leading to frequent inquiries in dental offices.

The shift toward hydroxyapatite products coincides with growing hesitation among some consumers regarding fluoride. Dr. Bennett Amaechi, a professor of dentistry at the University of Texas at San Antonio, observes that a growing number of people are refusing fluoride entirely or expressing doubt about using it for their children. This skepticism has been amplified by public health commentary, including claims by Health Secretary Robert F. Kennedy Jr. that water fluoridation contributes to health issues such as bone cancer, thyroid disease, and neurodevelopmental disorders.

Despite the public debate, health authorities maintain that low levels of fluoride are safe and effective. The Centers for Disease Control and Prevention states that adding fluoride to public drinking water reduces cavities by 25 percent. The agency previously listed water fluoridation among the top ten public health achievements of the 20th century. Researchers have found associations between fluoride and IQ loss, but those studies typically involved fluoride levels more than double the recommended amount in U.S. water supplies.

Hydroxyapatite is gaining traction because its chemical structure resembles tooth enamel. Dr. Livia Tenuta, a professor at the University of Michigan School of Dentistry, explains that fluoride protects teeth by remineralizing the enamel with calcium and phosphate. She describes fluoride as forming a shield for the outer layer of the tooth. Hydroxyapatite products, particularly those using nano-hydroxyapatite, are designed to penetrate tiny pores in the enamel with smaller particles, though the research data on this mechanism remains limited.

Early clinical trials suggest hydroxyapatite performs comparably to fluoride. Amaechi co-authored a 2021 study in Scientific Reports that tracked 177 children for nearly one year. The research compared tooth decay rates between groups using hydroxyapatite toothpaste and those using fluoride toothpaste, finding similar outcomes in both groups. That study received funding from Dr. Wolff Group, a German company that owns two hydroxyapatite toothpaste brands.

A second study, published in Frontiers in Public Health two years later, tracked 171 adults for 18 months. The researchers also found that both groups showed similar results regarding tooth decay. However, the participants in that study were mostly healthy young adults without severe oral health problems, which limits the generalizability of the findings.

Dr. Tenuta notes that there are very few long-term studies on hydroxyapatite, and those that exist often recruit participants with a low risk of caries. A 2019 study in the Journal of Investigative and Clinical Dentistry did examine 133 people at higher risk of caries. After just over five months, the researchers found that both hydroxyapatite and fluoride toothpastes performed similarly.

Cost remains a factor for consumers choosing between the two options. Hydroxyapatite toothpastes are generally more expensive, with some brands charging over a dollar more per ounce than their fluoride counterparts. For patients who are open to both choices, Amaechi advises using fluoride because it has a more extensive body of evidence supporting its efficacy.

The American Dental Association acknowledged in an email that more people are using hydroxyapatite products. Dr. Ada Cooper, a Consumer Advisor for the ADA, stated that while some evidence suggests these products contribute to remineralization, the research is new. She described the evidence regarding clinical effectiveness as limited and ambiguous, particularly regarding specific clinical indications. The ADA continues to recommend brushing twice daily for two minutes with a fluoride toothpaste, flossing daily, and visiting a dentist regularly.