Is Nano Hydroxyapatite Safe? A Dentist’s POV [2025]

By Gerry Curatola | Jul 04, 2025

Nanohydroxyapatite (HAp) has been touted as the new, safe fluoride. It is not.

Supporters may argue that hydroxyapatite in toothpastes and mouthwashes is safer than fluoride. That’s like comparing a hammer to the chest and a hammer to the face:

  • Fluoride is very dangerous to your short-term and long-term health. Countless studies have shown the side effects of fluoride use on our holistic health and our young children.

  • Hydroxyapatite is also dangerous. Though less thoroughly studied, researchers have already found HAp is not very effective, and it is found all over your body where it doesn’t belong. HAp can even penetrate your cells and lead to cellular damage.

Keep reading to learn the truth about nanohydroxyapatite, as well as safer alternatives to dental remineralization and oral health.

When properly supported, your oral microbiome can naturally remineralize teeth and support dental health. That’s why we created a toothpaste that supports your oral biome without impacting your whole-body health. Try Revitin today.

What Is Nano Hydroxyapatite? [Origins, Regulations & Different Forms]

Nanohydroxyapatite refers to nano-sized particles of the mineral hydroxyapatite, which is a toothpaste ingredient gaining recent popularity as a fluoride alternative and natural oral health ingredient. It’s said to remineralize teeth and prevent dental caries.

Developed by NASA in the 1970s, the ultra-fine nano HAp embeds itself into natural bone and dental structures to supports astronauts’ healthy teeth and bones. In the 1980s, a Japanese company, Sangi Co., obtained the patent from NASA and sold nano-HAp toothpaste on a small scale. In the early 2000s, Sangi Co. started making the nanoparticles considerably smaller.

Nanoparticles are extremely small, measuring less than 100 nanometers. (For comparison, a human hair is 80,000-100,000 nanometers thick.) They are able to penetrate microscopic pits and fissures in eroded enamel surfaces, which is great and dangerous at the same time.

When European companies started to sell HAp toothpastes, the European Union considered banning HAp in 2016. Though banned in cosmetic products, it is allowed in toothpastes and mouthwashes. There are no regulations on HAp in cosmetic products; however, HAp isn’t FDA-approved for cavity prevention.

Nano HAp particles are typically rod-shaped or needle-shaped. The needle-shaped HAp is more heavily regulated.

In 2023, the European Commission’s (EC) Scientific Committee on Consumer Safety (SCCS) considered “hydroxyapatite (nano) safe when used at concentrations up to 10% in toothpaste, and up to 0.465% in mouthwash.”

In an unsurprisingly confusing turn of events, the word “hydroxyapatite” may actually mean multiple things:

  • The naturally-occurring mineral that is a form of calcium apatite, which is a calcium phosphate

  • Microparticles of hydroxyapatite (greater than 100 nanometers)

  • Nanoparticles of hydroxyapatite (less than 100 nanometers)

What about micro-hydroxyapatite? Hydroxyapatite nanoparticles are more dangerous to your whole-body health than microparticles, but micro-hydroxyapatite is ineffective at remineralization.

Is Hydroxyapatite Toothpaste Safe?

Nanohydroxyapatite is not safe, so toothpastes that contain nano-HAp are also unsafe. Not only are they less effective at remineralization than naturally supporting your oral microbiome, their tiny particle size can cause cell damage and cause toxicity in organs throughout your body.

The use of hydroxyapatite in wellness-focused oral care formulations and products for children is either misguided or willfully harmful. Instead of biomimetic (mimicking biology) dental care like HAp, dentistry professionals should support natural biology, especially the oral microbiome.

Potential Benefits

Before we dive into the dangers, let’s talk about the positive effects of n-HAp.

Nanohydroxyapatite could potentially benefit your oral health in the following ways:

  • Remineralization: Though the safety of nano-hydroxyapatite is dubious, HAp can remineralize teeth. I argue that this enamel remineralization is damaging to your oral microbiome and whole-body health. Still, it’s true that hydroxyapatite works for remineralizing enamel by embedding in dental divots, releasing calcium ions, and preventing tooth decay.

  • Reduced tooth sensitivity: By blocking up exposed dentinal tubules, nanohydroxyapatite can strengthen tooth enamel against dentin hypersensitivity to cold and pressure.

  • Possible whitening agent: Nanohydroxyapatite may whiten teeth by filling in microscopic pits and fissures that can make the tooth surface appear rough and less white.

  • Improved dry mouth: Proponents argue that replacing alcohol-based mouthwash with hydroxyapatite mouthwash can reduce your risk of xerostomia (dry mouth).

Read Next: Heal Cavities With Food Instead of Harmful Toothpastes

Dangers of HAp Nanoparticles

Below are the major adverse effects and safety concerns when using hydroxyapatite nanoparticles:

  • Cytotoxicity: Nanoparticles in toothpaste are so small that they can penetrate cell membranes and damage mitochondria.

  • Ineffective remineralizer: Nanoparticles used to remineralize teeth are weak and subject to acid erosion. Nano HAp does not effectively prevent long-term demineralization.

  • Presence all over the body: Nanoparticles from hydroxyapatite toothpaste have been found in the lungs, the kidneys, and the bloodstream, impacting your holistic health. HAp is naturally occurring, but nanoparticles raise biocompatibility concerns.

  • Microbe killer: Proponents see HAp nanoparticles as a benefit because they seem to weaken bacteria biofilms, making it easier to kill bacteria. The problem? This antibacterial effect applies to both bad bacteria and beneficial bacteria, impacting your microbiome.

  •  Though rare, some people may have an allergic reaction to HAp nanoparticles.

Don’t fret. Just because hydroxyapatite isn’t right for your oral hygiene routine, there are plenty of ways to take care of your oral health, including flossing, a soft-bristled sonic toothbrush, oral probiotics, a healthy diet, and stress reduction.

Is Hydroxyapatite Better Than Fluoride?

Nano-hydroxyapatite toothpaste may be marginally safer than fluoride toothpaste, but I would not recommend either. Both of these are trying to force remineralizing agents onto/into your teeth, instead of supporting a healthy oral microbiome that naturally remineralizes your teeth.

While fluoride may cause a lot of major whole-body health problems beyond just fluorosis, nanoparticles of hydroxyapatite are 1) less effective than natural remineralization and 2) dangerous to your holistic health (though the current evidence indicates fluoride is worse).

But to be fair, we’ve been studying the dangers of fluoride for decades, even if various organizations have been gaslighting us about fluoride for just as long.

Other Dangerous Toothpaste Ingredients

Fluoride-free toothpaste does not mean safe toothpaste. Here are toothpaste ingredients that should avoided due to various safety concerns:

Related Reading: Good Toothpaste Ingredients

Natural Ways to Remineralize Teeth

Fortunately, there are natural ways to remineralize your teeth that don’t lead to whole-body health problems:

  • Support your microbiome: The good bacteria in your oral microbiome are essential to your oral and whole-body health. Many of the following tips are about supporting your oral microbiome’s natural ability to remineralize teeth.

  • Use oral probiotics: Daily oral probiotics, designed to increase the disease-preventing bacteria in your mouth, help support a healthy oral microbiome and remineralization.

  • Eat a pro-microbiome diet: A healthy diet should contain alkalizing, anti-inflammatory, antioxidant, and prebiotic foods. Eat crunchy foods that promote saliva production. Drink more water. Avoid excess sugar and starchy carbs.

  • Floss daily: Regular flossing can prevent interdental plaque from causing tooth decay and demineralization.

  • Regularly exercise: High-intensity exercise increases blood circulation, which is critical to your overall health, but particularly your oral health and dental mineralization.

  • Reduce stress levels: Stress may lead to teeth grinding and saliva reduction, contributing to demineralization. Consider meditation, going outside, cutting caffeine within 6 hours of bedtime, and reducing blue light exposure at night.

  • https://pmc.ncbi.nlm.nih.gov/articles/PMC10767493/You should stop using harsh, microbe-killing ingredients like detergent-based toothpastes and mouthwashes. It kills the good bacteria in your mouth and may slow your mouth’s natural remineralization process.

Most conventional and “natural” toothpastes are meant to kill bad bacteria, but antibacterial ingredients also kill the more-important beneficial bacteria in your mouth.

The best natural toothpaste is Revitin, which contains zero harmful ingredients and supports your oral microbiome’s natural ability to remineralize teeth. Check out Revitin online today!

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