<I>In Vitro</I> Bioactivity and Physical–Mechanical Properties of MnO<SUB>2</SUB> Substituted 45S5 Bioactive Glasses and Glass-Ceramics

Fe2O3 substituted 45S5 bioactive - glasses were prepared. Glass - derived Bioactive Glass - ceramics were obtained through controlled crystallization of bioactive glasses. Nucleation and crystallization regimes were determined by the parameters obtained from differential thermal analysis (DTA) of bioactive - glasses. The formed crystalline phases in bioactive glass - ceramics were identified using X - ray diffraction (XRD) analysis. Surfaces of bioactive glasses and glass - ceramics were investigated by fourier transform infrared (FTIR) reflectance spectrometry. The bioactivity of bioactive glasses and glass - ceramics was investigated through immersion studies in simulated body fluid (SBF) solution for different time periods by FTIR reflectance spectrometry with monitoring the pH changes and the concentration of silicon, sodium, calcium, phosphorus and iron ions in SBF solution. The density, micro hardness and flexural strength of bioactive glasses and glass - ceramics were measured. Experimental results show that a decrease in glass nucleation and crystallization temperature of 45S5 bioactive - glass by doping of Fe2O3 in it and the formation of crystalline phases of sodium calcium silicate, in bioactive glass - ceramics. The bioactivity nearly remains same by doping 1% of Fe2O3 by weight, but after that it decreases. Crystalliziation of bioactive glasses decreases the bioactivity. The density, micro hardness and flexural strength of bioactive glass - ceramics are higher than their respective bioactive glasses and also it increases with increasing Fe2O3 content.