Dissolution, leaching, and Al2O3 enrichment at the surface of bioactive glasses studied by solution analysis

✍ Scribed by Andersson, Ö. H. ;Rosenqvist, J. ;Karlsson, K. H.

• Publisher: John Wiley and Sons
• Year: 1993
• Tongue: English
• Weight: 585 KB
• Volume: 27
• Category: Article
• ISSN: 0021-9304
• DOI: 10.1002/jbm.820270713

✦ Synopsis

Five glass compositions in or near the bioactive region in the system SiOz -Naz 0 -CaO -Pz05 -A12 O3 -Bz O3 were studied in vitro by immersion in Tris buffer. The Si concentration can be taken as a measure of the amount of dissolved glass, whereas the Na concentration can be used to estimate the thickness of the Si-rich (Si gel) layer. Upon immersing a bioactive glass into Tris buffer, a surface layer of a few micrometer thickness is dissolved during the first 8 h. During the first few hours of immersion, the rate of dissolution of the glass network is equal to or exceeds that of the growth of the Si-rich layer. If the glass contains A1203, most of the aluminum that would be released due to dissolution of the silica network is enriched in the Si-rich surface layer that forms due to leaching. Al2O3 is not only bonded by the Si gel but also interferes with formation of calcium phosphate.