EFFECTS OF MgO WT.% ON THE STRUCTURE, MECHANICAL, AND BIOLOGICAL PROPERTIES OF BIOACTIVE GLASS-CERAMICS IN THE SiO2, Na2O, CaO, P2O5, MgO SYSTEM

Bioactive glass-ceramics used as a replacement material for bone tissues because of its bioactivity, compatibility, and abilities to form a crystallized hydroxyapatite (HA) bonding layer which has a similarity in composition and structure to the inorganic component of bones mineral phase. The major objectives of this research is estimating the effects of using MgO as an additive on the property of bioactive glass ceramic in 45SiO2, 24.5 Na2O, 6 P2O5, (24.5-x)CaO, X MgO where X= 0,1,3 and 5 wt.%. Bioactive glass ceramic was made by traditional glasses melting techniques at 1200°C for 2hr. Compressed sample sintered at (850)°C, the X-ray diffraction test confirmed the formations of (Na2CaSi3O8) and (Na2Ca2Si3O9) phases in the structure of pure bioglass-ceramic and with (1wt.%) MgO, while (Na2CaSiO4) and CaMg(SiO3)2 phases were present in the structure of bioglass-ceramic with (3wt.%)MgO, and CaMg(SiO3)2 phase in the structure of bioglass-ceramic with (5wt.%) MgO. Results of mechanical and physical studies showed that increasing (MgO wt.%) in glass structure led to improving the bending strength, compressive strength, microhardness, and density associating with decreasing in porosity. FTIR confirmed the formations of the Si-O-Mg bond. The biological test was done by immersion the sample in (SBF) simulated body fluid for (21 days). XRD, SEM and pH tests revealed that appetite layers made on the samples surface, giving an evidence of their bioactivity. As general the results of the present study demonstrate that partial replacements of CaO by MgO in 45S5 glass ceramic improve the mechanical properties without altering the bioactivity suggesting that glass ceramic was suitable for the biomedical applications