Modified acrylic bone cement with high amounts of ethoxytriethyleneglycol methacrylate

One cause of arthroplasty failure is the brittle mechanical behavior of bon e cements. However, the improvement of cement formulations must also be acc ompanied by the maintenance of a wide variety of characteristics. New bone cements were obtained by the substitution of high percentages, up to 60% (v /v), of methyl methacrylate (MMA) by a higher molecular weight and more hyd rophilic monomer, ethoxytriethyleneglycol methacrylate (TEG). The essential advantages of these materials were the decrease of maximum temperature tog ether with a decrease in the residual monomer content with respect to conve ntional cement formulations. The water absorption process obeyed diffusion laws and the equilibrium water content increased by the introduction of hig her percentages of the hydrophilic component. This characteristic had an ap preciable effect on the viscoelastic behavior analyzed by DMTA. These modif ied bone cements had reduced polymerization shrinkage and similar levels of porosity. Tensile test revealed that the introduction of TEGMA gave rise t o an important modification of the mechanical behavior, with a noticeable i ncrease in the fracture strain. This fact was also confirmed by means of th e analysis of the fracture surfaces by SEM. (C) 1999 Elsevier Science Ltd. All rights reserved.