Dentists weigh in on hydroxyapatite toothpaste surge

177 children participated in a 2021 study that compared two types of toothpaste, marking one of the few large-scale trials available on the fluoride-free alternative gaining popularity in dental offices. The study, published in Scientific Reports, tracked tooth decay in participants using hydroxyapatite and those using standard fluoride formulas for nearly a year. Researchers found that both groups experienced similar outcomes regarding cavity formation.

Dr. Jin-Ho Phark, an associate professor of clinical dentistry at the University of Southern California, says he is seeing a sharp rise in patient inquiries about these products. Many individuals arrive at appointments after seeing advertisements on social media, where influencers heavily promote the ingredient. Phark notes that the curiosity is not limited to patients, as dental students also frequently ask about the science behind the trend.

Hydroxyapatite is a calcium phosphate mineral that mimics the structure of natural tooth enamel. Unlike fluoride, which has been a staple in oral care since Procter & Gamble released Crest nationally in the late 1950s, hydroxyapatite works by filling tiny crevices in the enamel. Some products use nano-hydroxyapatite, which features smaller particles designed to penetrate tooth pores more easily. The goal is to remineralize the tooth surface without the use of fluoride.

The shift toward fluoride-free options has coincided with public hesitation regarding the mineral. Health Secretary Robert F. Kennedy Jr. has linked water fluoridation to various health issues, including arthritis, bone fractures, and neurodevelopmental disorders. While the Centers for Disease Control and Prevention state that fluoride reduces cavities by 25% and is a key public health achievement, some consumers remain wary. Bennett Amaechi, a professor of dentistry at the University of Texas at San Antonio, observes that many people are refusing fluoride entirely or expressing concern about its use in children.

A second study published in Frontiers in Public Health in 2023 followed 171 adults for 18 months. Similar to the pediatric trial, the researchers found that participants using hydroxyapatite toothpaste showed comparable results to those using fluoride. However, the participants in this study were mostly healthy young adults without severe oral health problems. A 2019 study in the Journal of Investigative and Clinical Dentistry included 133 individuals at higher risk for caries. After five months, the data showed that both toothpastes performed similarly.

Despite the positive initial findings, dental professionals advise caution. Dr. Livia Tenuta, an associate professor at the University of Michigan School of Dentistry, points out that there are very few studies involving participants with a high risk of tooth decay. She argues that long-term data is necessary to determine if the alternative is truly effective for all patients. Fluoride has been extensively studied for decades, providing a robust foundation for its recommendation in preventing decay.

Cost is another factor for consumers. Hydroxyapatite toothpastes generally cost more than their fluoride counterparts, with some brands charging over a dollar more per ounce. The American Dental Association acknowledged in an email that some evidence suggests hydroxyapatite can contribute to remineralization. However, Dr. Ada Cooper, the ADA's Consumer Advisor, noted that the research is new and the evidence regarding clinical effectiveness remains limited. The association continues to recommend brushing twice a day for two minutes with fluoride toothpaste, flossing daily, and visiting a dentist regularly.

Amaechi told NPR that for patients open to both options, he advises using fluoride because of the extensive body of evidence supporting its efficacy. He was an author on the 2021 study, which received funding from Dr. Wolff Group, a German company that owns two brands of hydroxyapatite toothpaste. The company also funded the 2023 adult study. Tenuta agrees with the recommendation, stating that sticking to fluoride is the best option given the current state of research.