Toothpaste Trends: Dentists weigh fluoride against hydroxyapatite

Dentists report a growing number of patients asking for alternatives to standard fluoride toothpaste, specifically products containing hydroxyapatite. Dr. Jin-Ho Phark, an associate professor of clinical dentistry at the University of Southern California, states that he hears this inquiry regularly from both patients and students. He notes that many consumers have encountered these products through social media, where influencers frequently promote them.

The shift in consumer preference follows a long-standing history of fluoride in oral care. According to the Centers for Disease Control and Prevention, fluoride toothpaste became common in the late 1950s after Procter & Gamble released Crest nationally. For decades, fluoride has served as the primary active ingredient in oral care products, helping to protect the outer layer of teeth from bacteria that cause cavities.

Recent skepticism toward fluoride has intensified due to public criticism. Health Secretary Robert F. Kennedy Jr. has attributed several health issues to water fluoridation, including arthritis, bone fractures, bone cancer, IQ loss, neurodevelopmental disorders, and thyroid disease. Dr. Bennett Amaechi, a professor of dentistry at the University of Texas at San Antonio, observes that more people are refusing fluoride or hesitating to use it, particularly for their children.

Despite the criticism, low levels of fluoride are generally considered safe and effective. The CDC has named the addition of fluoride to public drinking water one of the top 10 public health achievements of the 20th century. Data from the agency indicates that fluoride in water reduces cavities by 25 percent. Amaechi notes that studies linking fluoride to IQ loss have examined levels more than twice the recommended amount in U.S. water supplies.

Hydroxyapatite is a calcium phosphate mineral that mimics the composition of tooth enamel. Proponents argue that nano-hydroxyapatite particles can penetrate tiny crevices in the enamel to remineralize teeth. Dr. Livia Tenuta, an associate professor at the University of Michigan School of Dentistry, explains that fluoride works by bringing calcium and phosphate back to the tooth when present in saliva. Hydroxyapatite products are thought to function differently by getting into the enamel's pores.

Research comparing the two ingredients shows similar short-term results. A 2021 study in Scientific Reports tracked 177 children for nearly one year and found no difference in tooth decay between those using hydroxyapatite and those using fluoride. A 2023 study in Frontiers in Public Health tracked 171 adults for 18 months with similar outcomes. However, the participants in that study were mostly healthy young adults without severe oral health problems.

Both studies received funding from the Dr. Wolff Group, a German company that owns brands producing hydroxyapatite toothpaste. Another 2019 study in the Journal of Investigative and Clinical Dentistry compared the two ingredients in 133 people at higher risk for caries. After five months, researchers found both toothpastes performed similarly.

Dental experts caution that the evidence base for hydroxyapatite is still developing. Tenuta states there are very few studies, and those that exist often recruit participants with low caries risk. She wants to see more long-term studies, especially in high-risk populations. The American Dental Association acknowledges that some evidence suggests hydroxyapatite can contribute to remineralization but describes the clinical effectiveness as limited and ambiguous.

For patients open to either option, Amaechi advises using fluoride because it has more supporting evidence. He notes that fluoride is extensively researched in long-term studies. Tenuta agrees, recommending fluoride as the best option given the current data.

The American Dental Association continues to recommend brushing teeth twice a day for two minutes with a fluoride toothpaste, flossing daily, and visiting a dentist regularly. Hydroxyapatite toothpastes tend to cost more than fluoride versions, with some products selling for over a dollar more per ounce.