Fluoride and apatite formation in vivo and in vitro

Abstract

In recent years, the biomineralization process has attracted much interest from academics and industries for potential technological application. The rule in biomineralization is to have a variety of interfaces and surfaces which can act as nucleators. The ultimate step in any biomineralization process, i.e. the deposition of mineral, must conform to the driving forces operating on the system. A new paradigm in the assessment of the driving force for biomineralization is that a variety of ions existing in the mineralizing milieu are not a bystander, but are instead an active player that directly regulates the precipitation process and nature of biogenic apatites. Thus, the most putative stoichiometric model of a biomineral is (Ca)(5-x)(Mg)q(Na)u(HPO4)v(CO3)w(PO4)(3-y)(OH,F)(1-z). Fluoride participates in many aspects of calcium phosphate formation in vivo and has enormous effects on its process and on the nature and properties of the final products. In the development of biogenic apatites, fluoride ion in the mineralizing media is supposed to accelerate the hydrolysis of acidic precursor(s) and increase the growth rates by augmenting the driving force for precipitation. Inhibitory activities of ions and molecules are related to their adsorption onto the apatite surfaces. From theoretical and practical points of view, it is of paramount importance to elucidate and predict the effect and outcome of fluoride (accelerator) and inhibitors of biological relevance, because of their use in combination for healthcare in dentistry and medicine, e.g. prevention of dental caries and calculus deposition and in the formulation of antiosteoporosis treatments.

Synthetic tooth enamel: SEM characterization of a fluoride hydroxyapatite coating for dentistry applications

“…Fluoride ions are incorporated into the apatite lattice through precipitation and growth reactions. This substitution brings about a reduction in the volume of the unit cell, so that the chemical stability of the apatite lattice is greatly enhanced by the electrostatic bond between fluoride and the adjacent ions 10 . Associated with the biomimetic process, crystal growth can be used for dentistry applications on the enamel.…”

Calcite-packed columns for the removal of fluoride in industrial wastewater

“…As shown in Fig. Intermediate calcium phosphate solid phases were reported to uptake fluoride ions to form fluorapatite or a solid solution of hydroxyapatite and fluorapatite [13][14][15][16]. The reduction of phosphate concentrations would be attributed to the formation of calcium phosphate phases such as hydroxyapatite since the effluent calcium concentration increased proportionally until the breakthrough of phosphate occurred.…”

“…Under this condition, further removal of fluoride can be expected since calcium phosphate solids were reported to uptake fluoride ions to form fluorapatite [Ca 5 (PO 4 ) 3 F] or solid solution of hydroxyapatite and fluorapatite [13][14][15][16]. Under this condition, further removal of fluoride can be expected since calcium phosphate solids were reported to uptake fluoride ions to form fluorapatite [Ca 5 (PO 4 ) 3 F] or solid solution of hydroxyapatite and fluorapatite [13][14][15][16].…”

Adsorption of Serum Albumin onto Octacalcium Phosphate in Supersaturated Solutions Regarding Calcium Phosphate Phases

“…From the perspective of mineral crystal-matrix protein interactions, bone mineralization processes are typically accompanied by interactions between mineral crystals and proteins, including matrix proteins that are secreted by tissue-specific cells such as osteoblasts, in addition to circulating serum proteins [17] that together promote the formation of organized mineral/protein complexes in bone tissue [18]. Therefore, increased knowledge of how the surrounding tissue environment, in which materials are subjected to osteoclastic cellular phagocytosis and osteoblastic cellular mineralization, accompanying additional de novo calcium phosphate crystal deposition, regulates the mineral crystal-protein interaction.…”