Optimisation of the bioactivity of different bioactive glass and glass ceramics for biomedical applications

Abstract

Bone regeneration is required in many clinical issues as addressed by orthopaedic and dental medicine. The autogeneous bone graft is the gold standard, but host tissue is often scarce and can hardly be modeled to the shape required for successful reconstruction. In the present work, a series of phosphate based bioactive glasses and glass-ceramics were prepared by melt quenching technique and optimised for biomedical applications. From this work, we optimised the compositions of the prepared glasses and glass-ceramics with higher mechanical strength and bioactivity. The following characterization studies are focused on the examination of physical, chemical and mechanical properties of materials and thus, provide the necessary information to judge their suitability for clinical use in the human body. Artificial materials considered to be suitable for applications as implant materials were commonly tested by in vitro methods in laboratory in the simulating body fluid (SBF) media. XRD, SEM and FTIR analysis were used to confirm the formation of HAp layer on the surface of the prepared glasses and glass-ceramics during in vitro analysis and hence, used to optimise the composition of bioactive glasses for implant applications. The results indicate that the added metal oxides restructure the bonding in phosphate glasses results an increased cross link density and thus, results in higher network stability. The amount of metal oxides plays a major role in phosphate glass network and thus it decides the chemical durability and mechanical properties. In general, from the observed results that the higher amount of metal oxides inhibits the formation of hydroxyapatite/Ca-P formation during in vitro analysis. The presence of higher calcium phosphates and residual glassy phases in the glass-ceramics induces the formation of apatite layer. The chemical durability and mechanical properties of glass-ceramics were increased when compared with its corresponding glasses. newline