Surface modifications of a glass and a glass-ceramic of the MgO-3CaO.P2O5-SiO2 system in a simulated body fluid.
A glass of nominal composition (wt%) 17.25 MgO-52.75 3CaO.P2O5-30 SiO2 and a glass-ceramic obtained from it showed surface modifications when immersed in an acellular medium having a composition similar to that of human blood plasma. A (Ca, P)-rich layer, with an approximate Ca/P atomic ratio of 1.7, identified as hydroxyapatite, developed on both samples. The precipitated film on the glassy sample was weakly bonded, whereas that formed on the glass-ceramic was strongly adherent. The apatite precipitated during the in vitro tests on both samples grew as a needle-like structure with crystals about 150-200 nm long and 50-70 nm thick, as measured on specimens soaked for 1 month in the simulated body fluid (SBF). The presence of calcium and phosphate ions in the SBF contributed to the precipitation of the (Ca, P)-rich layers on both specimens.
Department of Ceramics and Glass Engineering, University of Avelro, Portugal.
J M
JM
Oliveira
R N
RN
Correia
M H
MH
Fernandes
D001665:Binding Sites; D001672:Biocompatible Materials / Q000737:chemistry*; D001769:Blood / Q000378:metabolism; D017610:Calcium Compounds / Q000737:chemistry; D002516:Ceramics / Q000737:chemistry*; D005898:Glass / Q000737:chemistry*; D066298:In Vitro Techniques; D008277:Magnesium Oxide / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D008956:Models, Chemical; D010087:Oxides / Q000737:chemistry; D010758:Phosphorus / Q000737:chemistry; D017553:Phosphorus Compounds; D012822:Silicon Dioxide / Q000737:chemistry; D013499:Surface Properties
D001672:Biocompatible Materials; D017610:Calcium Compounds; D010087:Oxides; D017553:Phosphorus Compounds; D010758:Phosphorus; D008277:Magnesium Oxide; C012500:phosphorus pentoxide; D012822:Silicon Dioxide; C023506:Glass ceramics; C016538:lime