Bioatividade de vidros e vitrocerâmicas do sistema 2Na2O.1CaO.3SiO2 com adições de P2O5, K2O E SrO

Abstract

The increase in life expectancy has led to the search for materials that can improve the quality of life. Among the materials that are most used to treat problems in bone tissue, bioactive glasses are those that have the greatest bioactive response. The 2Na2O.CaO.3SiO2 (2N1C3S) composition is one of the few glass systems which exhibits homogeneous crystallization in the volume and also its composition is very close to Bioglass® 45S5 glass, one of the most bioactive materials. In this work, we studied the bioactivity of 2N1C3S glass with additions of P2O5, K2O and SrO by investigating the time to formation of the hydroxycarbonate apatite (HCA) by immersion in simulated body fluid (SBF). Thermal treatments were carried out to evaluate the bioactivity of the glass-ceramics. The heat treatment temperatures were obtained by differential scanning calorimetry, in which the glass transition and crystallization onset temperatures were determined. The presence of HCA was investigated by Fourier transform infrared spectroscopy as a function of immersion time in SBH solution. X-ray diffraction were used for the identification of the crystalline phases present in the glass-ceramics. The glass-ceramics with the lowest time for growth of the hydroxycarbonate apatite layer in SBF solution were 2Na2O.CaO.3SiO2+6% in weight of P2O5 and 10% in weight of SrO heat treated for 620°C/16h and 2Na2O.1CaO.3SiO2+6% in weight of P2O5 and 10% in weight of K2O heat treated at 550°C/8h. The HCS layer was observed after 15 days of immersion for both glass-ceramics.