Estimation of elastic modulus, fracture toughness and strength of 47.5B-derived bioactive glass-ceramics for bone scaffold applications: a nanoindentation study

The knowledge of the mechanical properties of glass-ceramic materials used in bone scaffolds is the key to the optimal design of tissue engineering devices. In this paper, the elastic properties and fracture toughness of silicate bioactive glass-ceramics based on the 47.5B parent composition were quantified for the first time through nanoindentation. Specifically, the effect of sintering temperature was investigated by testing samples sintered at six different temperatures. The samples sintered at higher temperatures exhibited elastic modulus and fracture toughness higher than those of the lower temperature samples. Both properties are comparable with those shown by similar bioactive glasses available in literature, supporting the mechanical suitability of the materials for bone applications. An estimation of tensile strength as a function of flaw size is also provided by means of fracture mechanics approaches.