Dentin hydroxyapatite and exposed dentinal tubules (HAp)

Dentin hydroxyapatite is the primary inorganic mineral component of the tooth's dentin, organized into a complex crystalline structure of calcium and phosphate (PubChem CID 14781). When the protective layers of enamel or cementum are lost due to erosion or gingival recession, dentinal tubules—microscopic channels leading to the dental pulp—become exposed to the oral environment (StatPearls, NBK544332). According to the hydrodynamic theory, the movement of fluid within these exposed tubules in response to thermal, osmotic, or tactile stimuli triggers pulpal mechanoreceptors, resulting in the sharp pain characteristic of dentin hypersensitivity (Journal of Conservative Dentistry, PMC3010026). Therapeutic strategies focus on either desensitizing the pulpal nerves or physically sealing the tubule orifices to prevent fluid movement. Agents such as potassium nitrate work by increasing extracellular potassium concentration to inhibit nerve repolarization, while stannous fluoride and bioactive glasses promote the deposition of mineral precipitates onto the hydroxyapatite surface (NCBI, PMC3927677). Effective management of this target is essential for alleviating chronic dental pain and preventing further structural degradation of the tooth.

Other names

Dentinal tubulesDental hydroxyapatiteCalcium hydroxyapatiteExposed dentin

Nerve desensitization via potassium ion depolarization (StatPearls, NBK544332); physical occlusion of dentinal tubules to inhibit hydrodynamic fluid movement (Journal of Conservative Dentistry, PMC3010026); remineralization of the hydroxyapatite matrix (PubChem CID 14781).