Liquid phase sintering of hydroxyapatite by phosphate and silicate glass additions: structure and properties of the composites

Autor: Fernando J. Monteiro, G.W. Hastings, José D. Santos, Rui L. Reis, Jonathan C. Knowles
Rok vydání: 1995
Předmět:
Zdroj: Journal of Materials Science: Materials in Medicine. 6:348-352
ISSN: 1573-4838
0957-4530
DOI: 10.1007/bf00120303
Popis: Phosphate- and silicate-based glasses were added to hydroxyapatite in order to improve its mechanical properties and to fabricate composites with different degrees of bioactivity. A strong chemical bonding was obtained between hydroxyapatite and the phosphate-based glasses leading to samples approaching theoretical density, according to density measurements and scanning electron microscopy. Bioglass® additions led to the formation of a complex calcium phosphate silicate which hampered the reinforcement process. The fracture toughness of the hydroxyapatite-glass composites was shown to be within the 1.1–1.2 MPam1/2 range, which is double that determined for sintered hydroxyapatite. A 2 μm thick apatite layer was observed on the surface of the hydroxyapatite-glass composites after 48 h immersion in a simulated human blood plasma, whereas only a few apatite crystals were detected on sintered hydroxyapatite after 7 days immersion. From the results obtained we anticipate that the composites might show a higher rate of bone bonding, leading to enhanced bioactivity.
Databáze: OpenAIRE
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