Tooth enamel hydroxyapatite and dentinal mineral matrix (HAp)

Tooth enamel hydroxyapatite and the dentinal mineral matrix represent the primary inorganic structural components of the human dentition. Enamel is the most highly mineralized tissue in the body, consisting of approximately 96% crystalline hydroxyapatite, while dentin is a complex composite of mineral crystals embedded in a collagenous organic framework (NIH, 2022). These structures serve as a critical protective barrier for the internal dental pulp and provide the mechanical strength required for mastication. In dental pharmacology, this matrix is the central target for preventive and therapeutic agents designed to combat dental caries and acid erosion. Therapeutic interventions, such as the application of fluoride, work by integrating into the mineral lattice to enhance its chemical stability against bacterial acids (StatPearls, 2023). Furthermore, the dentinal matrix is targeted by materials that occlude exposed tubules to treat dentin hypersensitivity (Journal of Dental Research, 2019). Understanding the physicochemical properties of this matrix is essential for the development of biomimetic materials that can effectively repair or replace natural tooth structure.

Other names

HydroxyapatiteCarbonated hydroxyapatiteDental mineralBioapatiteCalcium phosphate apatiteTooth mineral matrix

The primary mechanism involves the chemical substitution of hydroxyl ions in the hydroxyapatite lattice with fluoride ions to form fluorapatite, which is significantly more resistant to acid-induced dissolution (StatPearls, 2023). Additionally, remineralizing agents provide a supersaturated environment of calcium and phosphate ions, often stabilized by proteins like casein phosphopeptide, to drive the precipitation of new mineral into porous enamel or dentin (PubMed, 2021). For dentin hypersensitivity, agents target the matrix by physically or chemically occluding the dentinal tubules, thereby blocking the hydrodynamic fluid flow that triggers nerve endings (NIH, 2020).