Enamel hydroxyapatite surface (HAP)

Enamel hydroxyapatite is the primary inorganic constituent of human tooth enamel, comprising approximately 96% of its weight and providing the extreme hardness required for mastication (StatPearls, 2023). It consists of a crystalline lattice of calcium and phosphate ions, specifically Ca10(PO4)6(OH)2, which exists in a dynamic equilibrium of demineralization and remineralization within the oral environment (NIH, 2022). This mineral surface is a critical therapeutic target in preventive dentistry; for example, fluoride ions interact with the surface to replace hydroxyl groups, forming fluorapatite which is significantly more resistant to acid dissolution by cariogenic bacteria (Journal of Dentistry, 2019). Beyond caries prevention, the hydroxyapatite surface is targeted by remineralizing agents like nano-hydroxyapatite and CPP-ACP to repair early-stage 'white spot' lesions and restore mineral density (Nature, 2019). Additionally, therapeutic agents target this surface to treat dentin hypersensitivity by occluding exposed tubules and reducing fluid movement (Scientific Reports, 2020). Understanding the physicochemical properties of this surface is essential for developing treatments that combat dental erosion and maintain oral health.

Other names

HydroxyapatiteDental hydroxyapatiteCrystalline calcium phosphateCarbonated hydroxyapatiteTooth mineral

Promotion of remineralization through ion deposition, substitution of hydroxyl groups with fluoride to form acid-resistant fluorapatite, and physical occlusion of dentinal tubules to block external stimuli.