Dentists Weigh Fluoride Against New Hydroxyapatite Toothpastes

The U.S. Centers for Disease Control and Prevention reports that fluoride in drinking water reduces cavities by 25 percent, a statistic that anchors the standard of care for oral health. Yet a growing segment of the public is turning to a different active ingredient: hydroxyapatite.

Dentists across the country are seeing a spike in inquiries about fluoride-free options. Dr. Jin-Ho Phark, an associate professor of clinical dentistry at the University of Southern California, notes that patients frequently ask about these products. He attributes the surge in popularity to social media marketing, where influencers have pushed hydroxyapatite brands aggressively to consumers.

The mineral is chemically similar to tooth enamel. Hydroxyapatite consists of calcium and phosphate, the same components that form the hard outer layer of teeth. Unlike fluoride, which works by creating a shield that helps remineralize teeth after brushing, hydroxyapatite is thought to fill tiny crevices in the enamel. Manufacturers often use nano-hydroxyapatite, a form with smaller particles designed to penetrate tooth pores more easily.

Research comparing the two ingredients shows mixed results on long-term efficacy. A 2021 study published in Scientific Reports followed 177 children for nearly one year. The researchers found that both the hydroxyapatite and fluoride groups had similar outcomes regarding tooth decay. 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 in 2023 tracked 171 adults over 18 months. Similar to the earlier trial, both groups showed comparable results in preventing decay. However, the participants in that study were mostly healthy young adults with low risk for severe oral health problems. Dr. Livia Tenuta, an associate professor at the University of Michigan School of Dentistry, points out that most available studies recruit participants with low caries risk, leaving a gap in data for high-risk patients.

One 2019 study in the Journal of Investigative and Clinical Dentistry addressed that gap by including 133 people at higher risk for caries. After five months, the researchers found that the hydroxyapatite toothpaste performed similarly to the fluoride option. Despite these findings, Bennett Amaechi, a professor of dentistry at the University of Texas at San Antonio, says fluoride remains the standard due to the volume of long-term research available.

The shift toward hydroxyapatite has coincided with public debate over fluoride safety. Health Secretary Robert F. Kennedy Jr. has linked water fluoridation to various health issues, including bone fractures and neurodevelopmental disorders. While the CDC previously named water fluoridation a top public health achievement of the 20th century, some consumers remain hesitant to use fluoride products, especially for children.

Cost is another factor for households. Hydroxyapatite toothpastes typically cost more than their fluoride counterparts, with some brands charging over a dollar more per ounce. The American Dental Association acknowledges that some evidence supports hydroxyapatite's ability to contribute to remineralization. However, Dr. Ada Cooper, the ADA's consumer advisor, wrote that evidence regarding its clinical effectiveness remains limited and ambiguous.

For patients deciding between the two, dentists generally recommend consistency. Dr. Phark and his colleagues advise brushing twice daily for two minutes. While the new mineral offers a viable alternative for those avoiding fluoride, the depth of the scientific record still favors the traditional ingredient for maintaining long-term dental health.