Is Nano-Hydroxyapatite Toothpaste an Effective Fluoride Alternative? Dentists Weigh In

CNET

15-07-2025

Picking the best toothpaste can be a challenge, especially with newer ingredients being added to the market. Nano-hydroxyapatite is a timely example and the star ingredient for popular brands like Boka and Davids. Amidst health concerns around fluoride and Robert F. Kennedy Jr., US Secretary of Health and Human Services, proposing to remove it from public water, nano-hydroxyapatite has been promoted as an effective alternative to fluoride in toothpaste. Many claim that it can repair enamel, prevent cavities and even whiten teeth.
"As ingredient labels shift toward cleaner, fluoride-free formulas, one compound is taking center stage in modern oral care: nano-hydroxyapatite," Dr. Pia Lieb, DDS, cosmetic dentist and clinical assistant professor emerita at NYU College of Dentistry, explains. Marketed as a biomimetic, enamel-restoring alternative to fluoride, this ingredient has gained a loyal following, but does the science justify the hype?
To find out if nano-hydroxyapatite toothpaste is worth incorporating into your dental care routine, and if it's a viable replacement for fluoride toothpaste, we reached out to dentists for the potential benefits, side effects and their expert opinions.
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.
Potential nano-hydroxyapatite toothpaste benefits
"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, 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."
Since nano-hydroxyapatite toothpastes are fluoride free, Dr. Yenile Y. Pinto, DDS, functional and biomimetic dentist and founder of Deering Dental, adds, "It's also been shown to reduce sensitivity and strengthen the enamel surface without the risk of fluorosis." Fluorosis occurs when you get too much fluoride as a child, causing white or brown spots on the teeth. The CDC reports that fluorosis typically doesn't affect tooth function and isn't painful.
A 2020 systematic review of 32 studies concluded that "Nano-HA is a relatively novel material with outstanding physical, chemical, mechanical and biological properties that makes it suitable for multiple interventions. It outperformed most of the classic materials used in implantology and surgery, but it should be further investigated for bone engineering and caries prevention therapy."
HengleinA 2023 comprehensive review found that, while more long-term studies are needed to establish the safety of regular use, "Nanohydroxyapatite is a promising revolutionary material in the prevention of early carious lesion mainly due to a greater source of free calcium."
Ultimately, providing a 2021 review and 2022 scoping review, Cooper concludes, "Although there is some evidence that alternative ingredients, such as [nano] hydroxyapatite, prevent tooth decay by acting as a remineralizing or anti-cavity agent, the studies are preliminary. The only anti-cavity agent recognized by the Food and Drug Administration in its over-the-counter monograph is fluoride, a naturally occurring chemical."
Cooper adds that all toothpastes with the ADA Seal of Acceptance contain fluoride. The administration specifically recommends brushing your teeth twice a day with fluoride toothpaste and regularly visiting your dentist.
Potential nano-hydroxyapatite toothpaste side effects and EU restrictions
"According to a [2021] narrative review from Odontology, the official journal of the Society of the Nippon Dental University, so far, there have been no reports of adverse dental or systemic effects of HAP-containing toothpastes because HAP has an excellent biocompatibility," states Cooper.
According to Austin, the concern with nano-hydroxyapatite is that, because it's made of nanoparticles, some worry about how much might get absorbed into the body if regularly swallowed. "The European Commission's Scientific Committee raised concerns due to the lack of long-term safety data on ingestion, particularly in children," she says. This has led to temporary nano-hydroxyapatite restrictions (not a full-on banning) in Europe.
The European Scientific Committee deems nHA safe in toothpaste up to 29.5% and up to 10% in mouthwash, per Tolmie. However, he states, "Regulators still bar it from breath-spray products to avoid lung exposure, so stick to pastes and rinses."
Key concerns around nano-hydroxyapatite, according to Lieb, are:
Potential ingestion and systemic absorption, especially in nano form
Lack of long-term studies in humans on the cumulative effects
Unknown impact of inhalation from aerosol products (not toothpaste)
In terms of systemic absorption, Sachar specifies, "Because nano-hydroxyapatite particles are similar in composition to bone mineral, there has been some theoretical concern that if absorbed systemically, they could potentially contribute to unwanted calcifications in soft tissues (like blood vessels or kidneys)." However, she states that this is speculative and not supported by any current clinical evidence.Is nano-hydroxyapatite toothpaste only effective at 10%?
"Most clinical formulations of nHA range from 5%-15%, with 10% emerging as the benchmark concentration in several Japanese and European studies," answers Lieb. "This concentration has demonstrated reliable enamel restoration while maintaining product stability and usability."
However, she states that newer formulations are experimenting with lower concentrations and enhanced delivery systems (such as encapsulation or synergistic minerals), which may improve efficacy at reduced levels. "The effectiveness isn't just about percentage, it's also about particle quality and how it's delivered to the tooth surface," she explains.
Tolmie adds, "Effective repair starts as low as 5% and plateaus around 10-15%. Several studies show that 5% n-HAp can mend enamel dings, divots and dents in the teeth, with benefits leveling off somewhere between 10% and 15%. One review even noted that 5% sometimes beats 10% because fewer particles clump, making them easier to slip into enamel defects; hence, most US brands sit comfortably in the 5-10% sweet spot."
Should people replace fluoride toothpaste with nano-hydroxyapatite?
Eversgerd states that it all depends on each person's oral health needs. "Fluoride remains the gold standard for cavity prevention, supported by decades of large-scale, randomized controlled trials," she explains. "However, for patients seeking a fluoride alternative -- whether due to sensitivity, allergies, personal preferences or a desire for a biomimetic approach -- nano-hydroxyapatite provides a scientifically supported option."
According to the Academy of Biomimetic Dentistry, a biomimetic approach is one in which damaged teeth are restored using materials mimicking natural teeth in function, strength and appearance.
For high-risk patients, Eversgerd recommends fluoride, while she may recommend n-Ha to low-risk or fluoride-averse individuals.
Austin seconds this, but adds that she also recommends fluoride toothpaste to children with poor brushing habits or communities with limited dental access. "nHA is a great option, but it's not a one-size-fits-all replacement for fluoride -- yet," Austin says.
Lieb explains that nHA may also be a compelling alternative for patients with aesthetic concerns, such as whitening-induced sensitivity, and individuals in preventive care regimens post-restorative treatment.
Pinto agrees that it depends on the person, stating, "For most of my patients, especially those with low to moderate cavity risk, nano-hydroxyapatite is an excellent option; gentler on the mouth, less drying and effective at rebuilding early damage. For people with high cavity risk, fluoride might still be the best choice, at least short term. For my high-risk patients, I often recommend a combo toothpaste that includes both ingredients when appropriate." Ultimately, if a patient isn't high risk and has health or safety concerns about fluoride, she thinks hydroxyapatite is a great option.
When asked if there's a reason people should choose n-HAp over other anti-cavity toothpastes, Tolmie answers, "No, as long as patients are brushing their teeth with an anti-cavity toothpaste. There are differences in the way an n-HAp toothpaste and a fluoride toothpaste work to prevent decay, and some n-HAp toothpastes may feel smoother on the teeth. But anti-cavity toothpastes as a whole accomplish the same task. Do I wash a car with tap water or bottled water? We know that both of them get the job done."
What's most important, according to Tolmie, is that patients ensure they're not swallowing toothpaste.
What does the American Dental Association think? Cooper states that the ADA recommends brushing teeth twice daily for two minutes with fluoride toothpaste, as the naturally occurring mineral has been proven to remineralize weakened enamel and reverse early signs of tooth decay.
"Additionally, the fluoride you take in from drinking water and other beverages continues to provide a topical benefit because it becomes part of your saliva, constantly bathing the teeth and helping to rebuild weakened tooth enamel," Cooper further explains. "The best scientific evidence has shown that adding fluoride to community water supplies is safe and effective. This is backed by decades of research and recognized by more than 100 health organizations."
GoodboyDoes nano-hydroxyapatite toothpaste work?
All of the dentists we consulted agree that nano-hydroxyapatite toothpaste works, but in the right context and with the right product. It's also not a miracle cure and should not replace your entire oral care routine, dentist's recommendations or regular appointments. Plus, Eversgerd adds that more long-term, large-scale trials are needed to fully validate whether it's equal to fluoride in preventing cavities.
When asked if it's effective, Austin says, "Yes -- particularly for enamel remineralization and sensitivity. In my practice, I've seen patients who switched to nHA toothpaste experience noticeable improvements in comfort, plaque control and surface smoothness. But like any product, it works best when paired with consistent brushing, flossing and professional cleanings."
Pinto agrees and has also seen the results firsthand. "It helps remineralize enamel, soothe sensitivity and support a healthier oral microbiome, especially when paired with a good routine (good home hygiene, healthy diet, hydration and nasal breathing)," she explains, noting that it's not a miracle cure, but does offer many benefits.
On behalf of the ADA, Cooper echoes Eversgerd's earlier statement: "The use of nano-hydroxyapatite (nHAP) in over-the-counter products is growing and some evidence shows that nHAP may contribute to remineralization, but the evidence is fairly new and often ambiguous, especially regarding clinical indications. "
Do experts recommend nano-hydroxyapatite toothpaste?
All of the experts we consulted do recommend nano-hydroxyapatite toothpaste, but only for certain patients. After all, according to Austin, "Nearly half of US adults over 30 have some form of gum disease, and you can't out-toothpaste a bad hygiene routine." Brushing your teeth regularly, flossing and regularly visiting your dentist are still essential, no matter what toothpaste you use.
Though Lieb recommends nHA toothpaste for adult patients experiencing post-whitening sensitivity or early enamel erosion, low-caries risk individuals seeking natural alternatives and adults undergoing cosmetic dental work who want to protect their investment with gentle, remineralizing care, she doesn't recommend nano-hydroxyapatite for children with deciduous dentition.
"In my professional opinion, fluoride remains the safest and most effective option for all patients under 14," says Lieb. "Its protective effect during the development of permanent dentition is unmatched, and its caries-prevention record is well established."
Sachar states that she often recommends it for "patients seeking fluoride-free options, those with mild tooth sensitivity and for children at risk of swallowing fluoride toothpaste." However, she advises that patients with moderate to high cavity risk not fully abandon fluoride.
Again, it's important to note that the "ADA recommends that adults brush their teeth twice daily with fluoride toothpaste for at least two minutes each time, or as directed by a licensed dentist," according to Cooper. This is because the proposed benefits of nHAP are fairly new and ambiguous.
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The bottom line
Though more research is needed, the dentists we consulted explained that nano-hydroxyapatite toothpaste can be an effective alternative to fluoride -- but only in the right context. The ADA doesn't recommend it. It's also not a miracle cure or a replacement for brushing regularly, flossing and professional dental appointments.
If you're considering nano-hydroxyapatite toothpaste, consult your dentist first before making the switch. They know your teeth best and will be able to help you find the best toothpaste for your smile.