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Abstract: 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. [Copyright &y& Elsevier]

Abstract: The response to metal dusting of Cr/Cr2O3 thin films deposited on 304L stainless steel substrates by reactive magnetron sputtering (RMS) under various deposition conditions was investigated. Selected coated samples and bare substrates were exposed to an atmosphere of CH4 +H2 +residual oxygen at 800°C for up to 20h via thermogravimetric analysis (TGA). The results indicate that the presence of the Cr/Cr oxide film resulted in a clear improvement in resistance against metal dusting of the 304L steel. The protective behavior of the Cr/Cr oxide coatings arises from several effects: decrease of catalytic deposition of carbon on the Cr oxide surface (and expected prevention of inward diffusion of carbon through the Cr oxide), and hindrance of outward Cr and Fe diffusion which were identified as important events in the metal dusting of the bare 304L steel. The structural differences among the various Cr/Cr oxide films prepared in the present conditions played a lesser role in their protective behavior than the presence of the outer Cr oxide layer. [Copyright &y& Elsevier]