Due to its outstanding properties such as biocompatibility, bioactivity, osteoconductivity and non toxicity and non inflammatory nature, nano-hydroxyapatite bioceramic has got a variety of applications in medical and oral care areas. Hydroxyapatite (HAp) is a calcium phosphate similar to the human hard tissues in morphology and composition. Weights of atoms and isotopes are from NIST article. The surface structure of hydroxyapatite (HAP) is crucial for its bioactivity. Sodium Fluoride is added to drinking water. 3.1.3 Molecular weight Molecular weight: 502.31 g/mol 3.1.4 Purity, composition and substance codes Company A and C (material 1): Hydroxyapatite as the main component; Potassium chloride (KCl) as preservative and water as excipient. Hydroxyapatite, also called hydroxylapatite (HA), is a naturally occurring mineral form of calcium apatite with the formula Ca 5 (PO 4) 3 (OH), but it is usually written Ca 10 (PO 4) 6 (OH) 2 to denote that the crystal unit cell comprises two entities. All the samples were cut into 2-mm-thick disks with a diameter of 15mm. hydroxyapatite: Ca10(PO4)6(OH)2 fluoroapatite: Ca10(PO4)6F2 Molecular mass (molecular weight) is the mass of one molecule of a substance and is expressed in the unified atomic mass units (u). 2014 Jun;14(6):872-80. doi: 10.1002/mabi.201300415. (1 u is equal to 1/12 the mass of one atom of carbon-12) Molar mass (molar weight) is the mass of one mole of a substance and is expressed in g/mol. Company B (material 2): “Artificially synthesized, amorphous, nano-disperse calcium % silica as dopant, synthetic, 574791 Hydroxyapatite, synthetic, 99.8% trace metals basis (excludes Mg), Using a molecular dynamics simulated annealing method, we studied the structure and its variation with annealing temperature of the HAP (100) surface. The molar mass of hydroxyapatite is 502 g/mol. Ultra-high molecular weight poly-ethylene (UHMWPE; Roechling, Munich, Germany) with a molecular weight of two million served as the control. We have used molecular dynamics simulations to investigate the early processes in the nucleation of hydroxyapatite at a collagen template, by immersing a triple-helical collagen molecule in a stoichiometric solution of Ca2+, PO43–, and OH– ions, where we have observed the formation of calcium phosphate clusters at the collagen template. The idea is to convert hydroxyapatite into more stable fluorapatite. Effects of physical and chemical treatments on the molecular weight and degradation of alginate-hydroxyapatite composites Macromol Biosci. Epub 2014 Jan 17. Hydroxyapatite, nanopowder, <200 nm particle size (BET), contains 5 wt. and molding process.