While the debate around fluoride continues, many are considering switching their fluoride toothpastes to alternatives that include the popular ingredient nano-hydroxyapatite. “As ingredient labels shift toward cleaner, fluoride-free formulas, one compound is taking center stage in modern oral care: nano-hydroxyapatite,” explains Dr. Pia Lieb, DDS, cosmetic dentist and clinical assistant professor emerita at NYU College of Dentistry.
If you’re thinking about trying a nano-hydroxyapatite toothpaste but aren’t sure if it’s right for you, we spoke to dentists to break down the benefits, potential risks and whether this ingredient actually works.
What is nano-hydroxyapatite?
“Nano-hydroxyapatite is a synthetic calcium phosphate compound that’s used in some oral care products, including toothpastes,” explains Dr. Ada Cooper, consumer advisor and spokesperson for the American Dental Association, says. “[It] has a structure that is similar to hydroxyapatite found in enamel, and nHAP gets incorporated into the tooth structure preferentially in demineralized areas.”
Nano-hydroxyapatite is also abbreviated as n-HA and n-HAp.
Dr. Royce Lai of King Village Dental adds that this is technically a two-part question, since “hydroxyapatite has been around for decades and has been studied for at least 20 years.” Newer and less studied, nano-hydroxyapatite is a version of hydroxyapatite with small, rod-shaped particles.
“Hydroxyapatite is natural. It is a type of calcium that makes up bones and teeth,” says Lai. “Nano-hydroxyapatite relates to the particle size. These are between 20 and 80 nanometers and are much smaller than the hydroxyapatite tubules that are a part of your teeth.”
According to Dr. Daniela Eversgerd, a cosmetic dentist and the founder of Allure Dental, nano-hydroxyapatite was developed by NASA in the 1970s for astronauts dealing with bone and enamel loss during long periods of space travel. Since the early 1990s, it has been approved for oral care products in Japan.
Nano-hydroxyapatite benefits in toothpaste
“Nano-hydroxyapatite doesn’t just protect your teeth — it helps rebuild them,” says Dr. Catrise Austin, a cosmetic dentist, author of Gum Health Made Simple and host of the Let’s Talk Smiles podcast. She lists the following as potential nano-hydroxyapatite benefits:
- Enamel remineralization
- Tooth sensitivity relief
- Reduced bacterial adhesion
- Whitening and gloss enhancement
“n-HA can actually fill microscopic cracks and help reverse or arrest early cavities,” adds dentist Dr. Sandip Sachar.
Austin cites a 2019 study that found a 10% hydroxyapatite toothpaste is equivalent or non-inferior to fluoride toothpaste for preventing and remineralizing dental cavities (or caries) in children.
When it comes to teeth sensitivity, Lai cites a 2014 study concluding that 15% nano-hydroxyapatite helped sensitive teeth. “The particle size could get into space and work better than larger particles in micro-hydroxyapatite or fluoride,” he explains. “The conclusion was that nano-hydroxyapatite could significantly reduce tooth sensitivity to hot and cold in two to four weeks of use.”
Referencing an 18-month 2023 clinical trial finding that a 10% n-HAp toothpaste protected adult teeth from new cavities as well as a standard 1,450-ppm fluoride paste, Dr. Christopher Tolmie, DDS, MBA, of PDS Health, states, “By patching enamel and calming swollen gums, nano-hydroxyapatite may cut off a hidden spark of chronic inflammation linked to heart disease and diabetes.”