Research findings: Hydroxyapatite Study Database
Studies on the active ingredient hydroxyapatite are published on an ongoing basis. Those with an interest in the science can, for example, gain a comprehensive overview via the international research database PubMed.
Hydroxyapatite: Hydroxyapatite improves dental health
Numerous scientific publications confirm the effectiveness of hydroxyapatite in dental care. This active ingredient protects against acids, forms a protective layer on the teeth, reduces sensitivity and improves gum health.
In collaboration with the Max Planck Institute, research was conducted to investigate whether hydroxyapatite particles can form a protective layer on the teeth. The analysis showed that a protective layer was formed at all the hydroxyapatite concentrations tested.
Hydroxyapatite particles, such as those used in Bioniq® dental care products, adhere to the teeth after just a short period of exposure. This adhesion occurs through polar interactions and acts as a protective layer against potential acid attacks.
Source:
Fabritius-Vilpoux, K., Enax, J., Herbig, M. (2018) Quantitative affinity parameters of synthetic hydroxyapatite and enamel surfaces in vitro, Bioinsp Biomim Nanobiomater, 8(2): 141–153.
The in vitro study shows that hydroxyapatite counteracts cariogenic acids in plaque biofilms by raising the pH level.
Furthermore, hydroxyapatite particles release calcium when neutralising acid. Calcium is important because it reduces the rate at which hydroxyapatite dissolves in tooth enamel and can promote remineralisation.
This study shows that hydroxyapatite from dental care products can effectively buffer various cariogenic and erosive acids and is a versatile ingredient that enables rapid acid neutralisation.
Source:
Cieplik, F., Rupp, C. M., Hirsch, S. et al. (2020): Ca²⁺ release and buffering effects of synthetic hydroxyapatite following bacterial acid challenge. BMC Oral Health 20:85.
Many foods and drinks contain acids that cause permanent damage to teeth. The reason is that when acids come into contact with teeth, they dissolve key components of the tooth mineral hydroxyapatite. This makes the enamel thinner and more vulnerable.
A protective layer of biomimetic hydroxyapatite on the tooth surface can prevent exactly that: it acts as a protective shield and stops the acids from attacking the enamel.
An in vitrostudy confirms that hydroxyapatite can neutralise up to 99.3% of the acid contained in cola and serves as protection against erosion and a source of calcium.
Source:
Fandrich, P., Stammler, F. J., Enax, J. et al. (2026): In vitro study on the neutralisation potential of particulate hydroxyapatite in erosive acids. BDJ Open 12:25.
Hydroxyapatite – the stuff our teeth are made of
Tooth enamel consists of around 97% hydroxyapatite.
Dentine consists of around 70% hydroxyapatite.
Repairs tooth enamel
Micro-fine active ingredient repairs defects and forms a protective layer on the tooth with every brush, helping protect against acid attacks.
Smoother teeth with daily use.
Whiter teeth
Hydroxyapatite adheres to the tooth, making it appear brighter. New stains find it difficult to adhere to the smooth tooth surface.
Helps protect against common dental problems
The microcrystalline structure of hydroxyapatite adheres directly to the surface of the enamel whilst brushing, smoothing the tooth surface. This makes it much harder for bacteria to adhere to the tooth.
It helps protect against enamel wear and gum problems.
Reduces tooth sensitivity
Targeted repair and restoration of the tooth enamel protect the sensitive tooth necks. Exposed dentinal tubules are sealed, helping to reduce tooth sensitivity. Helps reduce sensitivity to hot and cold food.
Enjoy hot and cold foods with greater comfort!
Repair: Hydroxyapatite remineralises and repairs tooth enamel
Our tooth enamel consists largely of the mineral hydroxyapatite, the hardest substance in the human body. However, tooth enamel wears away over time and cannot be regenerated by the body. The biomimetic active ingredient hydroxyapatite is therefore used in dental care, amongst other applications.
This study was the first to precisely measure how biomimetic hydroxyapatite adheres to real tooth surfaces.
Key findings:
- Biomimetic hydroxyapatite is so similar in structure to natural hydroxyapatite that it is considered a genuine biomimetic active ingredient.
- With a hydroxyapatite content of 10%, more than 30% of the tooth surface was coated with an even, single-layer protective film.
- Mineral bridges form between the biomimetic enamel and the natural enamel. The artificial enamel therefore bonds with the tooth at a mineral level, rather than simply sitting loosely on the surface.
The study provides scientific evidence of how artificial tooth enamel can be used effectively in dental care products to protect and repair teeth.
Source:
Fabritius-Vilpoux K. et al. (2019) Quantitative affinity parameters of synthetic hydroxyapatite and enamel surfaces in vitro, Bioinspired, Biomimetic and Nanobiomaterials 8 (2): 141–153.
A clinical trial compared the effectiveness of a toothpaste containing 10% hydroxyapatite and a fluoride toothpaste in preventing tooth decay and repairing damaged tooth structure.
The result: both toothpastes were shown to repair damaged tooth structure and prevent further damage to healthy enamel. There was no measurable difference in effectiveness between the two toothpastes. Artificial enamel is therefore on a par with fluoride.
An important difference in how they work: hydroxyapatite penetrates deep into the damaged tooth structure and repairs the enamel evenly from the inside out.
Source:
Amaechi, BT., AbdulAzees, PA., Alshareif, DO., Shehata, MA., Lima PPCS., Abdollahi, A., Kalkhorani, PS., Evans, V. (2019) Comparative efficacy of a hydroxyapatite and a fluoride toothpaste for the prevention and remineralisation of dental caries in children. BDJ Open. 9 Dec;5:18.
The microcrystalline structure of hydroxyapatite adheres directly to the surface of the enamel whilst brushing. This allows even the tiniest cracks and porous areas in the enamel to be repaired.
Gum protection: Hydroxyapatite improves periodontal health
If you do not remove plaque consistently, you risk not only tooth decay but, above all, serious gum problems. Plaque forms anew every day – particularly along the gum line. Bacteria living there can irritate and inflame the gums. What starts out as gingivitis can, over time, develop into periodontitis – a disease of the periodontium which, in the worst-case scenario, leads to tooth loss.
Dental care products containing hydroxyapatite can provide effective support here: this biomimetic active ingredient forms a smooth protective layer on the tooth enamel, making it much harder for bacteria and plaque to adhere. This reduces the strain on the gums, as less plaque accumulates at the gum line. Studies show that hydroxyapatite is just as effective as active ingredients previously considered particularly effective – whilst also having a proven positive effect on gum health.
In a clinical trial, patients with periodontitis were assessed for gum health. The use of a toothpaste containing hydroxyapatite proved just as effective at improving gum health as the products previously regarded as the gold standard. The plaque index (PCR, Plaque Control Record) and the level of gum inflammation were significantly reduced.
Source:
Harks I., Jockel-Schneider Y., Schlagenhauf U., et al. (2016) Impact of the Daily Use of a Microcrystalline Hydroxyapatite Toothpaste on De Novo Plaque Formation and Clinical/Microbiological Parameters of Periodontal Health. A Randomised Trial, PLOS ONE, 12; 11(2):50.
This study examined a mouthwash containing only hydroxyapatite particles. The hydroxyapatite particles adhered to the tooth surface and to bacteria in the saliva, thereby preventing bacteria from attaching to the teeth. Overall, significantly fewer bacteria adhered to the tooth surface compared to a mouthwash without hydroxyapatite.
Source:
Kensche, A., C. et al. (2017) Efficacy of a mouthwash based on hydroxyapatite in reducing initial bacterial colonisation in situ. Arch Oral Biol 80, 18–26.
Periodontitis often begins without anyone noticing. By taking early action to reduce plaque build-up along the gum line, you can effectively prevent the inflammation from progressing. This is precisely where hydroxyapatite comes in: as a preventive agent that lays the foundation for a healthy oral flora.
Joachim Enax
Senior Scientist, Oral Care
Relief for Sensitive Teeth: Hydroxyapatite helps reduce tooth sensitivity
Sensitive teeth often develop when the gums recede and the dentine – the layer beneath the enamel – is exposed. The dentine contains tiny tubules that are directly connected to the tooth’s nerve. Stimuli such as cold or sweet foods trigger fluid movements within these tubules, which can trigger sensations of sensitivity.
This is exactly where hydroxyapatite comes in: the fine particles settle on the exposed dentine, sealing the tubules and forming a protective mineral layer. At the same time, they release calcium and phosphate, which strengthen the dentine from the inside out. Fewer open dentine tubules can help reduce tooth sensitivity.
The systematic review and meta-analysis shows that hydroxyapatite toothpaste reduces sensitivity by an average of around 40 per cent compared with a placebo. is a more effective active ingredient for treating dentine hypersensitivity than fluoride.
Source:
Limeback, H., Enax, J., Meyer, F. (2023): Clinical Evidence of Biomimetic Hydroxyapatite in Oral Care Products for Reducing Dentin Hypersensitivity: An Updated Systematic Review and Meta-Analysis. Biomimetics 8(1), 23.
In addition to studies with standardised protocols, it is also important to conduct studies that take into account the individual behaviour of the participants. To this end, a study provided participants with toothpaste containing hydroxyapatite and toothpaste without it, without the participants knowing which of the two toothpastes they had been given. After a defined period of use, the participants were questioned about typical symptoms of pain sensitivity.
After just four weeks of daily use of a toothpaste containing hydroxyapatite, study participants reported significantly less toothache caused by sensitive teeth. They were noticeably better able to tolerate stimuli such as cold, sweet or sour foods.
What makes hydroxyapatite particularly special is its versatility: a single active ingredient reduces tooth sensitivity, repairs enamel and improves the appearance of the teeth.
Source:
Steinert, S. et al. Daily Application of a Toothpaste with Biomimetic Hydroxyapatite and Its Subjective Impact on Dentin Hypersensitivity, Tooth Smoothness, Tooth Whitening, Gum Bleeding, and Feeling of Freshness. Biomimetics 5(2):17, 1–11 (2020).
Causes of sensitive teeth
There are a number of possible causes of sensitive teeth. These can be divided into four categories:
Protection against tooth decay: Hydroxyapatite is effective in helping protect against tooth decay
Tooth decay is not just a problem for children – adults are affected too. Tooth enamel becomes thinner, the necks of the teeth are more frequently exposed and become more susceptible to acid attacks. As tooth enamel cannot regenerate itself, consistent prevention is crucial.
Dental care products containing hydroxyapatite target the very areas where tooth decay develops. The active ingredient remineralises the enamel, seals micro-cracks and forms a smooth protective layer on the tooth surface. This makes it harder for bacteria to adhere to the tooth. Furthermore, hydroxyapatite releases calcium when exposed to acid, actively protecting the tooth from mineral loss.
Clinical studies show that hydroxyapatite is just as effective in helping protect against tooth decay as traditional fluoride toothpastes.
Fluoride has been recognised as the proven active ingredient for protecting against tooth decay. The hydroxyapatite toothpaste performed just as well as the fluoride toothpaste tested.
Hydroxyapatite is therefore an effective and safe alternative to fluoride – particularly for people who wish to avoid fluoride or need to do so.
Source:
Paszynska, E., Pawinska, M., Enax, J. (2023): Caries-preventing effect of a hydroxyapatite toothpaste in adults: a 18-month double-blind randomised clinical trial. Front. Public Health 11:1199728.
This meta-analysis provides compelling evidence that hydroxyapatite in toothpastes and mouthwashes can effectively prevent tooth decay, without the need for fluoride.
The active ingredient strengthens and remineralises the tooth enamel, protects it from mineral loss and makes it harder for bacteria to adhere to the teeth – thereby also reducing the build-up of plaque.
Hydroxyapatite is well tolerated: none of the studies reviewed reported any side effects or allergic reactions. For people who wish to avoid fluoride, hydroxyapatite is therefore a safe and effective alternative – without compromising on protection against tooth decay.
Evidence regarding the effectiveness of hydroxyapatite-containing dental care products in reducing tooth decay has grown in recent years as a result of clinical trials. An increasing number of studies are demonstrating the effectiveness of hydroxyapatite as an anti-caries agent.
Source:
Pawinska, M., Paszynska, E., Amaechi, B.T. (2024): Clinical evidence of caries prevention by hydroxyapatite: An updated systematic review and meta-analysis. Journal of Dentistry 151:105429.
Dental Care by Dr Wolff: Bioniq®: Research at the cutting edge
Our commitment to research and innovation in dental care
Bioniq® is different because Dr Wolff is different. And so is our research. We don’t just sell dental care products with clinically proven efficacy; we actively work to advance research in dental health.