title: Compositional and microstructural changes of engineered plasma-sprayed hydroxyapatite coatings on Ti6Al4V substrates during incubation in protein-free simulated body fluid.
abstract: Hydroxyapatite (HAp) coatings engineered for maximum surface roughness (coating type I), porosity (coating type II), and tensile adhesion strength (coating type III) were deposited by atmospheric plasma spraying (APS) onto Ti6Al4V substrates and characterized for their microstructure, phase composition, and design properties. The composition of the as-sprayed coatings changed during treatment with protein-free simulated body fluid (Hank's Balanced Salt Solution, HBSS) for up to 12 weeks by preferential dissolution of thermal decomposition products, and amorphous calcium phosphate (ACP). From solutions supersaturated with respect to calcium and phosphorus ions, a thin, very porous layer precipitated onto the leached surfaces of coating type II samples after an incubation time of 8 weeks, consisting of spherical agglomerates of a poorly crystallized bone-like Ca-deficient defect hydroxyapatite that is thought to accelerate in vivo bone apposition rates and, hence, may induce favorable osseoconductive conditions.
authors.affiliation: Technical Mineralogy, Department of Mineralogy, Freiberg University of Mining and Technology, D-09596 Freiberg, Germany.
authors.forename: O
authors.initials: O
authors.lastname: Grassmann
authors.forename: R B
authors.initials: RB
authors.lastname: Heimann
mesh_terms: D000268:Adhesiveness; D000497:Alloys / Q000737:chemistry; D001826:Body Fluids / Q000737:chemistry; D002130:Calcium Phosphates; D020099:Coated Materials, Biocompatible / Q000737:chemistry; D003460:Crystallization; D017886:Durapatite / Q000737:chemistry; D004573:Electrolytes; D006801:Humans; D008855:Microscopy, Electron, Scanning; D016062:Porosity; D013059:Spectrum Analysis, Raman; D013499:Surface Properties; D013718:Tensile Strength; D014025:Titanium / Q000737:chemistry
chemical_list: D000497:Alloys; D002130:Calcium Phosphates; D020099:Coated Materials, Biocompatible; D004573:Electrolytes; C519480:amorphous calcium phosphate; C031462:titanium alloy (TiAl6V4); D017886:Durapatite; D014025:Titanium