Hydroxyapatite (Enamel) (HAP)

Enamel apatite, primarily composed of carbonated hydroxyapatite [Ca10(PO4)6(OH)2], is the hardest substance in the human body and forms the outer protective layer of the teeth (StatPearls, 2023). Its highly organized crystalline structure provides the mechanical strength necessary for mastication while acting as a physical barrier for the underlying dentin and pulp tissues (PubMed, PMID: 32731344). In the oral environment, this mineral undergoes constant dynamic cycles of demineralization and remineralization influenced by pH levels and microbial activity (NIH, 2022). Therapeutic interventions specifically target the enamel apatite lattice to enhance its resistance to acid-producing cariogenic bacteria. Fluoride-based treatments work by substituting hydroxyl groups in the apatite crystal to form fluorapatite, which has a lower solubility product and higher acid resistance (PubChem, CID 64155). Furthermore, biomimetic agents like nano-hydroxyapatite are utilized in modern dentistry to directly repair surface defects and reduce tooth sensitivity by occluding exposed dentinal tubules (Journal of Dentistry, 2019).

Other names

Carbonated hydroxyapatiteCalcium hydroxyapatiteDental apatiteBio-apatiteEnamel mineral

Promotion of remineralization through the formation of fluorapatite, which is more resistant to acid dissolution, or the direct deposition of synthetic hydroxyapatite to restore mineral density and occlude exposed dentinal tubules.