In vitro behavior of bioactive phosphate glass-ceramics from the system P2O5-Na2O-CaO containing titania

Soda lime phosphate bioglass-ceramics with incorporation of small additions of TiO2 were prepared in the metaphosphate and pyrophosphate region, using an appropriate two-step heat treatment of controlled crystallization defined by differential thermal analysis results. Identification and quantification of crystalline phases precipitated from the soda lime phosphate glasses were performed using X-ray diffraction analysis. Calcium pyrophosphate (beta-Ca2P2O7), sodium metaphosphate (NaPO3), calcium metaphosphate(beta-Ca(PO3)(2)), sodium pyrophosphate (Na4P2O7), sodium calcium phosphate (Na4Ca(PO3)(6)) and sodium titanium phosphate (Na5Ti(PO4)(3)) phases were detected in the prepared glass-ceramics. The degradation of the prepared glass-ceramics was carried out for different periods of time in simulated body fluid at 37 degrees C using granules in the range 0.300-0.600 mm. The released ions were estimated by atomic absorption spectroscopy and the surface textures were measured by scanning electron microscopy. Investigation of in vitro bioactivity of the prepared glass-ceramics was done by the measurement of the infrared reflection spectra for the samples after immersion in the simulated body fluid for different periods at 37 degrees C. The result showed that no apatite layer was formed on the surface of the samples and the dominant phase remained on the surface was beta-Ca2P2O7, which is known for its bioactivity. (C) 2008 Elsevier Ltd and Techna Group S.r.l. All rights reserved.