Effect of Ti and Mg dopants on the mechanical properties, solubility, and bioactivity in vitro of a Sr-containing phosphate based glass

Resorbable materials are desirable components for applications such as temporary implants, as they degrade in a controlled manner until completion of the osseointegration of the bone, eliminating the need of a second surgery to remove them. Phosphate based glasses (PBG) have properties that allow them to be used as hard tissue substitutes with the advantage of being resorbable. Incorporation of strontium into PBG has been widely studied because it is considered a bone formation stimulator. Although strontium phosphate glasses have better cellular response, their degradation rate is higher. Some studies show that the addition of TiO2 and MgO significantly reduces the degradation rate of soluble phosphate glasses. Furthermore, these oxides interfere with the chemical structure of the glass, and consequently improve their mechanical properties. Therefore, our aim was to evaluate the effect of dopants (TiO2 and MgO) on a phosphate based glass and, consequently, on its degradation behavior, hardness, elastic modulus and fracture toughness. Our results showed that the glass structure was modified by the dopants, becoming more rigid, and as a result, decreasing the glass degradation, and increasing the hardness, elastic modulus, and fracture toughness.