Hydroxyapatite (HAp) is a type of calcium that makes up 97 percent of your tooth enamel7 and 70 percent of the dentin of your teeth. The rest of your tooth enamel consists of collagen, water, and other proteins.
The chemical formula for hydroxyapatite is Ca5(PO4)3(OH). Hydroxyapatite is also the primary component of bones, making up 60 percent of them. In addition to toothpaste, hydroxyapatite is used in osteopathic research to help strengthen bone material. It is also used for restorative restorations and preventative materials.
The high hydroxyapatite concentration in tooth enamel is the reason it is so strong and robust. This main feature is the reason tooth decay can be prevented as our teeth are usually under constant acid-attacks.
As you eat, drink, and live your life, your teeth are consistently going through demineralization and dentine remineralization.
Tooth demineralization occurs when your teeth lose minerals. The bacteria in your mouth thrive off the sugars in the foods and drinks that you consume. They produce acids that wear away at your teeth.
Dentine remineralization is the repair process. Imagine it as re-hardening teeth that have become softened by those acids. Your body works to repair the enamel on the tooth surface and prevents mineral loss.
One way that your enamel repairs itself is when your saliva helps fill in the small cracks that have been left behind. This is done before they can grow bigger and let bacteria slip through, leading to cavities. Toothpastes or mouthwashes with fluoride or hydroxyapatite can help with the dentine remineralization process.
Toothpastes containing hydroxyapatite can create a barrier on your tooth surfaces. This barrier protects teeth against the sugars and acids that wear away at your teeth.
To use hydroxyapatite toothpastes, squeeze a pea-sized amount onto your toothbrush and brush your teeth for at least two minutes as you would with any other toothpaste. For the best results, do not rinse with water after you brush your teeth. This leaves the hydroxyapatite on your teeth for a strong remineralizing effect.
Depending on your toothpaste brand, hydroxyapatite toothpaste may taste like almost anything. For example, RiseWell’s kids' toothpaste has a vanilla birthday cake flavor.
However, Boka uses the traditional mint flavor you may be used to in toothpaste. These flavors are affected by other ingredients, including beneficial essential oils, xylitol or other sweeteners, and other flavors.
Yes, hydroxyapatite toothpaste does work for remineralizing teeth.
Your teeth consist of several layers. On the top, you have the hard outer layer known as enamel. The hard tissue underneath that is called dentin. When you reach down below the gum line, another hard substance called cementum covers and defends the roots.
These hard tissues consist of a blend of inorganic and organic substances and a small amount of water. The inorganic component consists of phosphate and calcium ions that produce strong hydroxyapatite crystals. When you eat, the crystals enable your teeth to withstand the forces of chewing, crunching, and grinding.
Yes, hydroxyapatite toothpaste is safe and beneficial for enamel.
A 2013 study demonstrated that your dental enamel is perhaps the hardest substance in your body.2 However, it is not invulnerable.
The following can chip away at enamel:
Once enamel is gone, you cannot get it back. However, you can increase the mineral content of the remaining enamel with remineralization. This strengthens the enamel.
Using toothpaste with hydroxyapatite helps remineralize your teeth. Your teeth absorb the hydroxyapatite and rebuild enamel with it.
A 2019 lab study discovered that hydroxyapatite toothpaste was as effective as toothpaste containing fluoride at stopping tooth demineralization and remineralizing the early signs of cavities.3
The randomized study suggested that hydroxyapatite toothpaste could be a helpful ingredient in dental products for people at significant risk of developing cavities. This is because it can trigger remineralization without adding extra fluoride. It also removes the worry about the toxicity that comes with higher quantities of fluoride.
The hydroxyapatite in toothpaste is a synthetic form of the same substance.
Using hydroxyapatite toothpaste has several advantages:
Like with any toothpaste, hydroxyapatite toothpaste allows you to physically sweep away the residue of food and bacteria lingering in your mouth.
Bacteria in the mouth can lead to tooth decay. They stop acid from breaking down the traces of foods and drinks that linger in your mouth when you do not brush your teeth after a meal. As a result, the acid can start dissolving tooth enamel, making them susceptible to cavities.
A 2017 in vitro study demonstrated that hydroxyapatite toothpaste could create a shield against bacteria to protect your teeth, making them more resistant to dental plaque. Plus, the toothpaste helps fill in those small cracks or fissures that occur in your teeth during tooth demineralization, so the bacteria cannot move down into your teeth.
If you experience tooth sensitivity, hydroxyapatite toothpaste may help your teeth feel less sensitive as it is strengthening your enamel.
One of the biggest cons of fluoride toothpastes is that fluoride, in high doses, is a neurotoxicant. This means it is a toxin that affects the brain. Fluoride is also a controversial topic for many people.
However, hydroxyapatite toothpaste is biocompatible, and your body recognizes it as a substance that belongs there.
The CDC discovered that most kids use more toothpaste than they should.5 This is a significant issue regarding toothpaste with hundreds of times the amount of fluoride than is found in water.
One of the benefits of using hydroxyapatite toothpaste is an increased whitening effect.
While HAp does not adjust the polishing activity of the toothpaste, it incorporates a whitening element not otherwise found in standard toothpaste.6
Using hydroxyapatite toothpaste helps defend your teeth from acid attacks by bacteria without adversely affecting your oral microbiome.
On the other hand, fluoride is bactericidal, which means it kills bacteria in the mouth. Many oral care brands think that by removing bacteria, they are improving the health of the mouth.
However, the oral microbiome requires a decent balance of bacteria to function well and keep your mouth healthy. Agents like chlorhexidine, triclosan, or alcohol may temporarily reduce bacterial overgrowth issues, but they can lead to other health problems over time.
Not only does hydroxyapatite toothpaste prevent acid attacks, but it will not destroy your oral microbiome.
The pH of the mouth should always be slightly alkaline to prevent inflammation and oral disease. Hydroxyapatite toothpaste helps teeth become more resistant to acidic pH in the mouth, which would otherwise break down enamel faster.
Using HAp toothpaste may help improve and strengthen gum and dental health in patients with gum disease. Improvements include dental plaque control, pocket depth, and bleeding gums.
There may be rare circumstances of someone experiencing an allergic reaction to hydroxyapatite toothpaste. However, there is no evidence to suggest a likelihood of experiencing any side effects from hydroxyapatite toothpaste.
A 2019 study demonstrated that toothpaste with hydroxyapatite is unlikely to irritate your teeth and mouth. It does not seem to introduce any safety concerns.4
Toothpaste with synthetic hydroxyapatite became popular in Japan following approval for use as a treatment against cavities around the early 1990s. A type using smaller particles, called nano hydroxyapatite toothpaste was introduced later.
Your dentist can provide you with prescription-strength hydroxyapatite with a more significant concentration of hydroxyapatite. But unless your teeth are at high risk, you may consider an over-the-counter (OTC) option.
Some types of hydroxyapatite contain the nanocrystal form. They are usually advertised as ‘nanohydroxyapatite remineralizing toothpastes.’ Others may include a formula that is blended with zinc.
There are even options that feature extra-mild aromas for young children.
Here are some effective HAp toothpaste brands to choose from:
Ebadifar, Asghar et al. “Effect of nano-hydroxyapatite toothpaste on microhardness of artificial carious lesions created on extracted teeth.” Journal of dental research, dental clinics, dental prospects vol. 11,1 (2017): 14-17
Nath, Subrata. (2013). Addition of Hydroxyapatite to Toothpaste and Its Effect to Dentin Remineralization. Korean Journal of Material Research. 23. 168-176.
Amaechi, B.T., AbdulAzees, P.A., Alshareif, D.O. et al. Comparative efficacy of a hydroxyapatite and a fluoride toothpaste for prevention and remineralization of dental caries in children. BDJ Open 5, 18 (2019)
Coelho, C.C., Grenho, L., Gomes, P.S. et al. Nano-hydroxyapatite in oral care cosmetics: characterization and cytotoxicity assessment. Sci Rep 9, 11050 (2019)
Thornton-Evans, Gina et al. “Use of Toothpaste and Toothbrushing Patterns Among Children and Adolescents - United States, 2013-2016.” MMWR. Morbidity and mortality weekly report vol. 68,4 87-90. 1 Feb. 2019
Niwa, M et al. “Polishing and whitening properties of toothpaste containing hydroxyapatite.” Journal of materials science. Materials in medicine vol. 12,3 (2001): 277-81
Meyer, Frederic et al. “Overview of Calcium Phosphates used in Biomimetic Oral Care.” The open dentistry journal vol. 12 406-423. 31 May. 2018