Tooth mineral hydroxyapatite and dentinal tubules (HAP)

Tooth mineral hydroxyapatite is a crystalline calcium phosphate (Ca10(PO4)6(OH)2) that constitutes the primary inorganic component of dental enamel and dentin, providing the hardness necessary for mastication (PubChem CID 14781). Dentinal tubules are microscopic, fluid-filled channels that traverse the dentin, connecting the dental pulp to the enamel-dentin junction and serving as a conduit for sensory signals (StatPearls: Physiology, Enamel). In conditions such as dentin hypersensitivity, the exposure of these tubules allows external stimuli to trigger fluid movement, which activates pulpal nerves according to the hydrodynamic theory (Journal of Conservative Dentistry, 2014). Therapeutic agents target these structures to either strengthen the mineral matrix or physically block the tubule orifices. Fluoride ions interact with hydroxyapatite to form fluorapatite, a more acid-resistant mineral that prevents dental caries (American Dental Association). Meanwhile, desensitizing agents like stannous fluoride, bioactive glass, and arginine-calcium carbonate complexes work by occluding the tubules to prevent the transmission of painful stimuli (British Dental Journal, 2013). Together, these components represent the primary physical and chemical targets for preventive and restorative dentistry.

Other names

Calcium hydroxyapatiteDentin tubulesDental mineral matrixCrystalline calcium phosphateMicrotubules of dentin

Remineralization of the hydroxyapatite matrix to form acid-resistant fluorapatite and physical occlusion of dentinal tubules to inhibit hydrodynamic fluid movement and subsequent nerve activation.