Effect of crystallization on apatite-layer formation of bioactive glass 45S5.
The bioactive glass 45S5 was crystallized to 8-100 vol % of crystals by thermal treatments from 550-680 degrees C. The micro-structure of the glass-ceramics had a very uniform crystal size, ranging from 8 to 20 microns. Fourier-transform infrared (FTIR) spectroscopy was used to determine the rate of hydroxycarbonate apatite (HCA) formation that occurs on bioactive glass and glass-ceramic implants when exposed to simulated body fluid (SBF) solutions. Crystallization did not inhibit development of a crystalline HCA layer, but the onset time of crystallization increased from 10 h for the parent glass to 22 h for 100% crystallized glass-ceramic. The rate of surface reactions was slower when the percentage of crystallization was > or = 60%.
Peitl Filho
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São Carlos Federal University, São Paulo, Brazil.
LaTorre
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GP
Hench
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LL
D001031:Apatites; D002254:Carbonates; D003460:Crystallization; D018360:Crystallography, X-Ray; D005898:Glass; D007700:Kinetics; D017550:Spectroscopy, Fourier Transform Infrared; D013499:Surface Properties
D001031:Apatites; D002254:Carbonates