Dr. Michelle Jorgensen

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Is Hydroxyapatite Safe? Uncovering the Truth in 2024


There is a new player in the oral health care product area called hydroxyapatite. Nano hydroxyapatite and micro hydroxyapatite have been added to oral care products without a lot of explanation and have created controversy in the industry . . . and left many asking the question: Is Hydroxyapatite Safe?

Everyone wants cleaner, stronger, whiter teeth and healthy gums., but is hydroxyapatite the magic ingredient some claim to help deliver these results?  

Are there safety concerns we should be aware of?  

Scores of research articles have given us answers to these questions.

I’ll explain how…

  • The right kind of hydroxyapatite
  • Used in the correct amounts
  • And with the correct methods

…has incredible benefits for the mouth and the body over comparable products of the past. 

Let’s dive in and uncover the truth: is hydroxyapatite effective and safe to use in 2023?

Understanding Hydroxyapatite


Have you ever wondered what makes our teeth and bones so strong? 

Hydroxyapatite is a mineral form of calcium apatite (calcium phosphate), and is a key component of both teeth and bones.  

The exact composition can vary, but in general, hydroxyapatite crystals make up about 70% of the weight of our bones and 96% of the enamel on our teeth.  That same naturally occurring organic material is now being used in tooth products for remineralization and repair. 

Component %  Composition of Hydroxyapatite
Bones 70%
Enamel on Teeth 96%

Hydroxyapatite can come from natural sources, including…

  • Cow and other animal bones
  • Egg shells
  • Fish scales

…or it can be synthesized in a lab.  

Due to common concerns with animal products, as well as sterilization, purity, and processing challenges, most hydroxyapatite that is used in dental care products is synthesized.  

This process creates a very small, pure product that can be safely used in the mouth. There are two common sizes in mouth care…

…nano hydroxyapatite, and micro hydroxyapatite…

…and both have been used in dentistry.  

Nano hydroxyapatite refers to hydroxyapatite particles that range from 1 to 100 nanometers in size. 1 These particles are EXTREMELY small,  providing a higher surface area compared to larger particles.  

Micro hydroxyapatite, on the other hand, refers to hydroxyapatite particles that are larger, typically ranging from 100 nanometers (nm) to 10 micrometers (µm) in size. Micro hydroxyapatite particles are still small compared to many other particles, but they are significantly larger than nano-sized particles. 

Size Scale Measurement
Nano 1-100 nm
Micro 100 nm – 1 µm
Conversion 1000 nm = 1 µm

The Science Behind Hydroxyapatite

So, how exactly does hydroxyapatite work in dental health products? 

The science behind it is fascinating. When the enamel is exposed to acids (either produced by bacteria in the mouth or from acidic foods and drinks) minerals are pulled out of the tooth surface. 

This is called demineralization. 

This leaves the tooth susceptible to attack from bacteria . . . which leads to tooth decay or cavities. 

Remineralization is the process of putting minerals BACK INTO the enamel, repairing and strengthening it.  

When hydroxyapatite particles come into contact with the tooth enamel, they release calcium and phosphate ions.2 These ions interact with the minerals in the enamel and saliva, leading to the formation of a new layer of apatite crystals on the tooth surface. 

This new layer leads to some expected and some surprising results:

  • Remineralization (repairing and strengthening teeth): The mineral crystals help remineralize and repair demineralized or damaged enamel, and protect against future mineral loss and tooth decay.

  • Desensitization (surface protection and cavity prevention): The hydroxyapatite acts as a protective barrier on the tooth surface, rapidly desensitizing the tooth and preventing further demineralization.

  • Whitening and smoothing: The hydroxyapatite smooths the tooth surface by filling in microscopic pits and fissures, reducing surface roughness and making the tooth more resistant to bacteria and acid.  This also leads to whitening and brightening of the tooth.

Hydroxyapatite Works Deeper Than Just the Enamel

Hydroxyapatite can also work deep into the tooth.  Underneath the enamel is the dentin layer which contains thousands of tiny tubes called dentinal tubules.  These tubes extend from the pulp (innermost layer) of the tooth to the outer enamel surface. 


The openings to these tubules are usually covered with enamel, but that enamel can be worn away from things like…


  • Tooth wear 
  • Gum recession
  • Dental procedures

…all which lead to sensitivity and deeper tooth decay. 

Studies have shown that hydroxyapatite particles have the potential to get into these dentinal tubules 3blocking access to other substances and making the dentin layer harder, less sensitive, and more resistant to decay. 

This is when particle size is important.

The hydroxyapatite particles have to be smaller than the openings of the tubules for these deeper benefits. 

Dentinal tubules are 1.7 µm at the DEJ 4 . Hydroxyapatite particles that are 500 nm or smaller will fit well inside the tubules, but larger hydroxyapatite particles will most likely only remineralize the enamel surface of the tooth.  

You will want hydroxyapatite products that contain 100 nm-500 nm size particles (considered micro hydroxyapatite) for the most benefit.

Research About Hydroxyapatite

First used in toothpaste in Japan in the 80s and 90s, hydroxyapatite toothpaste has only recently gained international attention. Some products with hydroxyapatite are FDA approved for use…

…but as with any new product, there are questions about whether they live up to the claims. 

Do hydroxyapatite toothpaste products really work? 

Are they safe for long-term use and are there any potential risks with these tiny particles? 

The use of hydroxyapatite in dental products has sparked a debate among dental professionals and consumers alike . . . raising questions about its effectiveness and safety.  

Below I’ll break down the published research on the topic and show you what has been discovered.

Hydroxyapatite Remineralizes Teeth

Enamel is the hardest mineralized structure of the human body, and is made of crystals. Water and mineral ions pass right through the enamel crystals, leading to minerals being lost and added (demineralization and remineralization), throughout the life of the tooth.  

Does hydroxyapatite add these minerals back to the tooth?

Decades of research have shown definitively that yes, hydroxyapatite is effective in remineralizing teeth, strengthening, protecting and even repairing teeth. 2,5,6,7

In fact, in a 2022 study, hydroxyapatite, as well as combinations of fluoride and calcium phosphate were shown to all remineralize the teeth, but the “hydroxyapatite showed the highest remineralization potential”.6

Hydroxyapatite Desensitizes Teeth

A recent study investigated the desensitizing activity of nano hydroxyapatite toothpaste.  The conclusion was that “The hydroxyapatite toothpaste tested caused a reduction of hypersensitivity/pain values higher than conventional fluoride toothpaste.”8,9

And the great news for sensitive tooth sufferers is that research shows that hydroxyapatite not only “effectively reduced dentin hypersensitivity, but the effect was instant and long-lasting.”  10

Hydroxyapatite Whitens Teeth

One of the surprising benefits of hydroxyapatite is its ability to whiten and brighten teeth!

Participants in a study that were trying one of these new products reported “their tooth surface as smoother, tooth color as whiter, and reported a stronger feeling of freshness after toothbrushing.” 11

Another study concluded that “hydroxyapatite is a promising whitening agent for oral care formulations and represents a biomimetic alternative to other whitening agents for daily dental care.”12

This is particularly promising, as other whitening products can have undesired side effects, and the side effects of hydroxyapatite are desired, including less sensitive and more cavity-resistant teeth. 13

Hydroxyapatite Helps With Gum Health

Better gum health is another surprising and welcome side effect of hydroxyapatite!  

The gold standard for treating gum disease in dentistry is chlorhexidine.  Used in a rinse, it can stain teeth, tastes bad, and can be toxic to cells. 14,15,16   

The great news is that hydroxyapatite, alone (and in combination with small particles or silver in a rinse), is even more effective than the old gold standard…

…and brings all the other benefits we have already discussed!  

Hydroxyapatite in a rinse with silver can:

  • Stop bacteria from sticking to the teeth.17,18

  • Kill bacteria that lead to tooth decay and gum disease.17,19,20,21

  • Maintain healthy bacteria while improving gum and tooth health.22,23,24

This table summarizes the dental health benefits found in the current research:

Dental Health Benefits of Hydroxyapatite
Hydroxyapatite Remineralizes Teeth
– Effective in remineralizing, strengthening, and cleaning teeth
– Shown to have the highest remineralization potential in a study
Hydroxyapatite Desensitizes Teeth
– Caused a reduction in hypersensitivity/pain values more than fluoride toothpaste
– Instant and long-lasting effect on dentin hypersensitivity
Hydroxyapatite Whitens Teeth
– Participants reported whiter teeth and fresher feeling after use
– Promising whitening agent for daily dental care
Hydroxyapatite Helps with Gum Health
– More effective than chlorhexidine in treating gum disease
– Stops bacteria from sticking to teeth
– Kills bacteria that cause tooth decay and gum disease
– Improves gum and tooth health while maintaining healthy bacteria

Hydroxyapatite vs. Fluoride

When it comes to protecting our teeth from decay and strengthening our enamel . . .  there is no debate that both hydroxyapatite and fluoride toothpaste help. 

Fluoride and hydroxyapatite have shown similar efficacy for… 

  • Remineralizing tooth enamel
  • Reducing the size of cavities
  • And stopping progressing decay.

However, hydroxyapatite has benefits fluoride doesn’t share. 

Studies have shown that hydroxyapatite toothpaste is a safer alternative to fluoride toothpaste. 

Fluoride is incorporated into teeth and bones . . .  and changes the crystal structure. 

Too much fluoride leads to a condition called fluorosis where the teeth are spotted or “mottled” with white and brown pits and holes in the enamel. 

fluorosis of the enamel
Fluorosis of the teeth, caused by ingestion of excess amounts of fluoride

A big concern is that there is fluoride in water, foods, and canned beverages and products.  It’s difficult to know or control the dosage, and fluoride poisoning may occur with repeated use. 25,26

This is particularly concerning in young children using fluoride-containing oral care products. 

There is a limit to fluoride dose allowed in oral care products to avoid the risk of fluorosis in children 26,28,29 and toxicity in all ages 30.

The fluoride dose recommended for toddlers and children is even lower than the 1000–1500 ppm fluoride concentration in non-prescription toothpaste sold in the stores.  These products are not safe for children. 

Thankfully there is research showing the effectiveness of hydroxyapatite as a fluoride replacement for children and adults. In a 2019 study, 10% hydroxyapatite achieved comparable remineralization and prevention as fluoride.

The study concluded, “Thus the Hydroxyapatite toothpaste is confirmed to be equal to the fluoride toothpaste in this study.” 31,32 Numerous other studies have shown hydroxyapatite to be as effective as fluoride in remineralizing and preventing tooth decay. 33,34,35 

In addition, hydroxyapatite tooth products can be a great tool for teaching children about oral hygiene. Its non-toxic nature means that parents can worry less about their children accidentally swallowing toothpaste during brushing. 

However, as with any oral care product, it’s important to supervise children during brushing and teach them to spit out toothpaste after use.

Dental Benefits Comparison: Hydroxyapatite vs. Fluoride
Dental BenefitsHydroxyapatite ToothpasteFluoride Toothpaste
Remineralizing enamelYesYes
Reducing cavitiesYesYes
Stopping decay progressYesYes
SafetySafer alternativeConcerns with excess fluoride
Fluorosis riskNoneHigh
Toxicity riskNoneHigh
Recommended for childrenYesCaution advised
Effectiveness in childrenComparable to fluorideComparable to fluoride

Is Hydroxyapatite Safe?

With all of the benefits, there is concern that these particles may have safety concerns. There is also concern about:

  1. The shape of the particle
  2. The percentage of nano hydroxyapatite particles in the product. 

Let’s tackle these concerns one at a time…

Hydroxyapatite is safe when used orally

One advantage of oral use of hydroxyapatite is that when hydroxyapatite particles are swallowed, they enter the stomach and completely dissolve.36  

A study reported, “There is no risk from an oral uptake of calcium phosphate(hydroxyapatite) nanoparticles due to their rapid dissolution in the stomach.37

The particles can also enter the body through the gum tissue, but the SCCS in Europe found that hydroxyapatite particles in numerous studies did not get into the body through intact gum tissue.1  

These studies show systemic health problems are not a risk for oral use of hydroxyapatite.

Hydroxyapatite does not lead to cell damage

The SCCS in its 2021 opinion paper also claimed possible cytotoxicity and genotoxicity, so researchers have been working hard to prove or disprove these concerns. 

A later 2021 study on nano hydroxyapatite particles showed safety for cells and DNA, stating “excellent cytocompatibility and absence of genotoxicity are clearly demonstrated, rendering it suitable for commercial use.38  

The shape and size of hydroxyapatite don’t lead to safety concerns

A lot of concern has been raised about the shape and size of the hydroxyapatite particles and their safety.  

  • Bone hydroxyapatite is 40-60 nm in size and needle and plate-shaped. 
  • The hydroxyapatite in enamel is in hexagonal rods and is much larger, 40-1000 nm in size.39  

A recent study showed that “there is no indication for a significant influence of the calcium phosphate phase or the particle shape (e.g. spherical or rod-like) on the biological response. In summary, the risk associated with an exposition to nanoparticulate calcium phosphate in doses that are usually applied in biomedicine, health care products, and cosmetics is very low and most likely not present at all.40  

What this means is that the shape and the size is less important than the dosage of the hydroxyapatite.

What percent of hydroxyapatite is a safe and effective dosage?

What percentage of hydroxyapatite is safe while delivering all of these benefits to the teeth and the mouth?  

A 2019 study on toothpaste efficacy showed, “10% hydroxyapatite achieved comparable efficacy with 500 ppm F− in remineralizing initial caries and preventing demineralization. Thus the hydroxyapatite toothpaste is confirmed to be equal to the fluoride toothpaste in this study.”9 

Dental Care Products That Deliver all the Benefits of Hydroxyapatite Safely and Effectively

When I first started researching nano hydroxyapatite, micro hydroxyapatite, and nano hydroxyapatite toothpastes, I made a list of the characteristics that the perfect product would have.  

This is the list I came up with:

  1. Hydroxyapatite should be a size small enough to get into dentinal tubules (less than 500 nm)

  2. Hydroxyapatite should be in a dosage of 10-15% of the product

  3. Hydroxyapatite should be synthesized for purity and safety

  4. Hydroxyapatite should be in a needle or rod-shaped to be biocompatible

  5. Hydroxyapatite should be combined with silver particles for added gum health

Failing to find an all-in-one solution with these advantages, I opted to create my own hydroxyapatite toothpowder and mouth rinse that fulfilled my desired oral health benefits.

Hydroxyapatite Toothpowder from Living Well with Dr. Michelle

My Remineralizing Tooth Powder is designed to help with remineralize teeth, rebuild enamel, and eliminating tooth sensitivity

It combines the powerful effects of hydroxyapatite with bentonite clay and healing essential oils. The remineralizing hydroxyapatite toothpowder contains:

  • Calcium Carbonate

  • Xylitol

  • Bentonite

  • Hydroxyapatite

  • Mentha Viridis (Spearmint) Leaf Oil

  • Gaultheria Procumbens (Wintergreen) Leaf Oil

  • Plantain (Plantago Major) Leaf Extract

The hydroxyapatite in all of my toothpowders is synthesized in a carefully selected lab to be 200 nm in size and needle-shaped.  It is 15% of the total formula.  

This makes it easy for the hydroxyapatite particles to get into the enamel and remineralize, protect against decay and whiten, and into the dentin to desensitize and strengthen the tooth.  

It is designed to maximize the remineralizing capabilities of hydroxyapatite in the safest form possible.

Four Types of Hydroxyapatite Tooth Powder Available

I created four different varieties of tooth powder.  All four varieties contain hydroxyapatite, but each one also has some other characteristics to choose from. 

All four varieties of tooth powder are ideal for healing and remineralizing teeth.  In order to also provide a solution for gum health, I created a hydroxyapatite rinse that is designed to help both the teeth AND gums.

Hydroxyapatite Mouth Rinse from Living Well with Dr. Michelle

This mouth rinse incorporates the oral health benefits of hydroxyapatite and combined them with silver and other healing herbs.

My hydroxyapatite mouth rinse has the following ingredients:


  • 10 ppm Silver Soltuion

  • Hydroxyapatite

  • Xylitol

  • Plantain Extract

  • Calendula Extract

  • Marshmallow Extract

  • Lavender Oil

  • Peppermint Oil

The mouth rinse combines 200 nm hydroxyapatite with silver particles in solution.  This creates a protective layer that prevents bacteria from sticking to the tooth, preserves healthy bacteria in the mouth, and freshens breath. 

The mouth rinse also contains healing herbs to combat dry mouth, inflammation, and gum irritation.

After using, the mouth feels fresh, the teeth feel smooth and the gums are healthier.

Tw Types of Hydroxyapatite Mouth Rinse Available

Both mouth rinse formulas offer comparable remineralization benefits, with the mint version containing mint essential oils and the citrus version flavored with orange peel.

In conclusion…

Research confirms the safety of hydroxyapatite, endorsing its use in oral health products. 

As a promising fluoride toothpaste alternative, hydroxyapatite dental products boast a myriad of benefits, including:

  • Enamel remineralization
  • Tooth sensitivity alleviation
  • Teeth whitening
  • Gum health improvement

…and cavity prevention.

Hydroxyapatite proves to be a powerful tool for oral care.

I hope this article has shed light on hydroxyapatite’s significance in dental health products.

Explore my hydroxyapatite tooth powder and mouth rinse to experience the remarkable health advantages firsthand today!

Picture of Dr. Michelle Jorgensen DDS

Dr. Michelle Jorgensen DDS

Dr. Michelle Jorgensen is an author, speaker, teacher, biologic/holistic dentist, and health and wellness, provider. After practicing traditional dentistry for 10 years, Dr. Jorgensen became very sick. Through her own journey to return to health, she discovered she had mercury poisoning from drilling out mercury fillings for her patients. She was concerned that there may be other health-threatening materials or procedures in dentistry and this led her to the Biologic/Holistic Dentistry field.

For the last 15 years, she has been paving the way in Biologic/Holistic dentistry, learning from pioneers all over the world. She has created the Total Care Dental Way, a patient CARE centric, health-focused method for treating dental and overall health. Patients from around the world seek out her care and come to Total Care Dental to have their health restored.


Frequently Asked Questions

Do dentists recommend hydroxyapatite?

Yes, dentists have started recommending hydroxyapatite dental products for stronger cavity-resistant teeth as an alternative to fluoride toothpaste due to its non-toxic properties. 

Is hydroxyapatite safe to consume?

Hydroxyapatite is non-toxic and biocompatible, making it safe for consumption. Plus, since it’s naturally occurring in our bodies, you don’t have to worry about you or your child swallowing it.

Is hydroxyapatite toothpaste approved by the FDA?

Yes, some types of hydroxyapatite toothpaste have been approved by the FDA for their ability to repair enamel. This is great news for those who are looking for a way to restore their enamel and protect their teeth from further damage.

What are the effects of hydroxyapatite?

Hydroxyapatite is a naturally occurring calcium and phosphate compound found in our teeth and bones.  In dentistry and oral care products, it is used for remineralization, it helps to reduce tooth sensitivity, prevents tooth loss, helps with plaque control, and whitens teeth.


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