STP1196: Structural Changes of Plasma Sprayed Hydroxyapatite Coatings During In-Vitro Testing

    Gross, KA
    Graduate student and professor, The Thermal Spray LaboratoryState University of New York, Stony Brook, NY

    Berndt, CC
    Graduate student and professor, The Thermal Spray LaboratoryState University of New York, Stony Brook, NY

    Pages: 16    Published: Jan 1994


    Abstract

    The in-vitro behavior of hydroxyapatite (HAp) coatings depends on the thermal history of the coating after thermal spraying. As-sprayed amorphous coatings degrade in Ringer's solution. Heat treatment at 800 °C for 2 hours produces a crystalline coating which upon immersion in physiological solution displays a greater stability. Coatings are characterized for surface morphology, composition, crystallinity, roughness, and weight loss. The as-sprayed coating shows changes in the coating morphology with immersion time. Individual lamellae crack and separate from the coating. Those lamellae still intact show evidence of dissolution. After a period of 8 weeks small HAp spheres cover the surface of the as-sprayed and heat treated coatings. These morphological changes are expected to influence the rate of bone bonding. Therefore post-treatment of HAp coatings is seen as a technique to alter or control implant-tissue interactions.

    Keywords:

    hydroxyapatite, amorphous, crystalline, Ringer's solution, degradation mechanisms, microstructure, structure


    Paper ID: STP25188S

    Committee/Subcommittee: F04.19

    DOI: 10.1520/STP25188S


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