AREPALLI SAMPATH KUMAR
Articles written in Bulletin of Materials Science
Volume 38 Issue 4 August 2015 pp 957-964
Bioactive glasses are materials capable of bonding implants to tissues. 45S5 Bio-glass® is one such material capable of bonding strongly to bone within 6 weeks. It develops a hydroxy-carbonate apatite layer on the implant that is chemically and crystallographically equivalent to the mineral phase of bone. However, it suffers from a mechanical weakness and low fracture toughness due to an amorphous glass network and is not suitable for load-bearing applications. In order to improve its mechanical strength and bioactivity, the present work explores the effects of cobalt oxide additions. Bioactivity of the glass samples was assessed through their hydroxyapatite formation ability by immersing them in the simulated body fluid for different soaking periods. The formation of hydroxyapatite was confirmed by Fourier transform infrared spectrometry, pH measurement and microstructure evaluation through scanning electron microscopy. Densities and mechanical properties of the samples were found to increase considerably with an increase in the concentration of cobalt oxide.
Volume 39 Issue 2 April 2016 pp 365-376
The aim of the present investigation was to study the role of Al$_2$O$_3$ in the Li$_2$O–CaO–P$_2$O$_5$–SiO$_2$ bioactive glass for improving the bioactivity and other physico-mechanical properties of glass. A comparative studyon structural and physico-mechanical properties and bioactivity of glasses were reported. The structural properties of glasses were investigated by X-ray diffraction, Fourier transform infrared spectrometry, scanning electronmicroscopy and the bioactivity of the glasses was evaluated by in vitro test in simulated body fluid (SBF). Density, compressive strength, Vickers hardness and ultrasonic wave velocity of glass samples were measured to investigatephysical and mechanical properties. Results indicated that partial molar replacement of Li$_2$O by Al$_2$O$_3$ resulted in a significant increase in mechanical properties of glasses. In vitro studies of samples in SBF had shown that the pH of the solution increased after immersion of samples during the initial stage and then after reaching maxima it decreased with the increase in the immersion time. In vitro test in SBF indicated that the addition of Al$_2$O$_3$ up to 1.5 mol% resulted in an increase in bioactivity where as further addition of Al$_2$O$_3$ caused a decrease in bioactivity of the samples. The biocompatibility of these bioactive glass samples was studied using human osteoblast (MG-63) cell lines. The results obtained suggested that Li$_2$O–CaO–Al$_2$O$_3$–P$_2$O$_5$–SiO$_2$-based bioactive glasses containing alumina would be potential materials for biomedical applications.
Volume 42 | Issue 6
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