Improvement of the mechanical properties of acrylic bone cements by substitution of the radio-opaque agent

Acrylic bone cements become radio-opaque by the addition of an inorganic co mpound, commonly BaSO4 or ZrO2. However, the use of these additives has som e negative effects such as loss of mechanical properties, risk of release a nd bone resorption. The use of the monomer 2,5-diiodo-8-quinolyl methacryla te (IHQM), which shows adequate polymerization and radio-opacity properties , is proposed as a new X-ray opaque, methacrylate iodine-containing agent. The aim of this study is to determine the effect of this new radio-opaque a gent on the mechanical properties of acrylic bone cements. The addition of the iodine-containing methacrylate provides a statistically significant inc rease in the tensile strength, fracture toughness and ductility, with respe ct to the barium sulphate-containing cement. This effect can be attributed to the fact that the use of a radio-opaque monomer eliminates the porosity associated with the barium sulfate particles, which show no adhesion to the matrix. However, some reinforcing effect must also be attributed to the io dine-containing monomer, since the tensile and fracture toughness values re ached are even higher than those shown by the radiolucent cement. (C) 1999 Kluwer Academic Publishers.