Dental enamel (main biological tissue) and Hydroxyapatite (main mineral component) (Enamel (no universal abbreviation; Hydroxyapatite often abbreviated as HAp or HA))

Dental enamel is the outermost, highly mineralized layer of teeth, consisting predominantly (95-98%) of hydroxyapatite crystals arranged in rods that provide exceptional hardness and resistance to mechanical wear[3][5][6]. Hydroxyapatite, with the formula Ca₁₀(PO₄)₆(OH)₂, is the principal mineral phase making up enamel, dentin, and bone, conferring both structural rigidity and chemical stability[1][4]. The organization and interaction of hydroxyapatite nanocrystals within the enamel matrix give teeth their durable barrier function yet make them vulnerable to demineralization by acids, underlying the pathogenesis of dental caries and erosion[3][6]. While not themselves molecular drug targets, enamel and hydroxyapatite surfaces are the focus of therapeutic interventions aimed at remineralization and protection, such as fluoride and bioactive mineral compounds[1][4].

Other names

EnamelHApHAHydroxylapatiteApatite

Fluoride ions replace hydroxyl groups in hydroxyapatite, forming fluorapatite which resists acid dissolution. Remineralization of enamel by deposition of calcium and phosphate, restoring lost mineral content. Nano-hydroxyapatite particles fill enamel defects and promote repair/regrowth of surface mineral.