Bioactivity and mechanical properties of SiO2-CaO-P205 glass-ceramics

• Published in: Journal of materials chemistry 2005-04, Vol.15 (13), p.1353-1359
• Main Authors: Vallet-Regi, M, Roman, J, Padilla, S, Doadrio, J C, Gil, F J
• Format: Article
• Language: English
• ISSN: 0959-9428; 1364-5501
• DOI: 10.1039/b415134h

Glass-ceramics in the system SiO,-Ca0-P-,05, with 55 mol% of silicon content, with and without phosphorus, were obtained by thermal treatment of sol -gel glasses as the precursors. The influence of the composition of the precursor glass on the crystallisation, bioactive behaviour and mechanical properties of these glass-ceramics was investigated. An interesting result is that when phosphorus was not present in the precursor glass, the biaxial flexural strength of the glass-ceramics increased by one order of magnitude. The crystalline phases obtained were similar in both glass-ceramics, although when phosphorus was present the crystallisation of tricalcium phosphate and the stabilisation of the Wollastonite phase at high temperature in the glass-ceramic took place Both glass-ceramics, without and with phosphorus, showed a fast in vitro bioactive response; a new apatite-like layer fully covered the surface of both materials after soaking in simulated body fluid for a short time. The rate of the apatite layer formation mainly depended on the sintering process, which took place at lower temperatures in the glass-ceramics without phosphorus. The glass-ceramics containing phosphorus showed a decrease in the values of the Weibull coefficient, an increase of porosity and pore size, and a heterogeneous microstructure, worsening their mechanical properties.