Ca₁₀(PO₄)₆(OH)₂

Hydroxyapatite (chemical formula: Ca₁₀(PO₄)₆(OH)₂ ) is a natural mineral that makes up about 97% of tooth enamel and 70% of bone structure. This means that it is biocompatible with the human body — the body "recognizes" it as its own material.

Most commonly used nano-hydroxyapatite (nHAp) – particles of such a size that they can penetrate microscopic enamel defects .

This an alternative to fluoride , which has been widely used in Japan (since 1970) and is now rapidly gaining popularity in Europe.

Especially suitable for people with sensitive teeth , after bleaching , after orthodontic treatment , or for those who are intolerant to fluoride .

How does hydroxyapatite work in dental care?

Remineralizes enamel

When acids (from food or bacteria) damage enamel, microscopic holes and cracks form. Hydroxyapatite nanoparticles fill these damaged areas, the mineral structure is restored , and the surface becomes smooth and strong. Unlike fluorine, it directly restores the mineral composition of enamel , not just protects against decay.

Reduces tooth sensitivity

When the enamel layer is damaged, dentinal tubules open, through which irritants (heat, cold, acids) reach the nerve. Hydroxyapatite closes these tubules , so sensitivity gradually decreases.

Gives the surface smoothness and shine

As the enamel microsurface is restored, the teeth become smoother , less plaque accumulates, and the surface becomes natural shine .

Whitens gently and without abrasives

Does not bleach chemically, but optical effect – smooth enamel reflects light better, making teeth appear brighter and healthier .

Prevents bacteria from attaching

Hydroxyapatite particles binds to the cell walls of bacteria , reducing their ability to attach to enamel and form plaque.

Main sources

1. Tschoppe, P.; Zandim, DL; Martus, P.; Kielbassa, AM (2011).
   "Enamel and dentine remineralization by nano-hydroxyapatite toothpastes." Journal of Dentistry , 39(6) , 430–437.
   DOI: 10.1016/j.jdent.2011.03.008 ScienceDirect +2 The Open Dentistry Journal +2

   • This in vitro study demonstrates that nano-HAp toothpastes can remineralize enamel and dentin and is compared to amino fluoride toothpaste. The Open Dentistry Journal +3 ResearchGate +3 SciSpace +3

2. Comparative efficacy of a hydroxyapatite and a fluoride toothpaste (Nature / Scientific Reports, 2019).
   "10% hydroxyapatite achieved comparable efficacy with 500 ppm F⁻ in remineralizing initial caries and preventing demineralization." Nature

   • Shows that a certain concentration of hydroxyapatite can be similar in effectiveness to a conventional fluoride product. Nature

3. "The use of hydroxyapatite toothpaste to prevent dental caries" (2021).
   The authors review the use of micro-/nanocrystalline HAP as an alternative to fluoride. DOI/journal: Odontology (or Archives of Oral Biology / Archives of Biology themed journal) – you should check the publication for accuracy, but the article is available via pmc. SpringerLink

   • Theoretical and clinical data on the effect of HAP on enamel restoration and inhibition of demineralization are presented. PMC +1

4. "Nanohydroxyapatite in dentistry: A comprehensive review" (PMC) [review].
   A wide range of studies are reviewed, including desensitization, remineralization, and clinical aspects. PMC

   • Indicates that pastes with 10–15% nHAp can effectively cover dentinal tubules. PMC

5. Jnanobiotechnology (2019).
   "Enamel remineralization and repair results of Biomimetic Hydroxyapatite"
   This work investigated a fluoride-free, biomimetic HAP formulation, its enamel-restoring ability, and its antibiofilm effects. BioMed Central

6. Clinical evidence of caries prevention by hydroxyapatite: An updated systematic review and meta-analysis
   A recently published meta-analysis, which includes clinical and in situ studies, evaluates the effectiveness of HAP in caries prevention. ResearchGate

   • Conclusion: HAP can reduce the risk of caries without fluoride.