An acrylic radiopaque bone cement for orthopedic use comprises a solid
phase composed of a mixture of at least one poly(methyl acrylate)-based
polymer, one free-radical polymerization initiator and one or more
substances opaque to X-rays, and a liquid phase substantially composed of
a mixture of at least one monomer, one accelerator and one stabilizer.
The radiopaque substances comprise metallic tungsten and tantalum
particles, compounds or mixtures thereof, covered with a polymer coating
compatible with said bone cement. The coating layer of the particles of
radiopaque substances is an acrylic polymer based on poly(methyl
methacrylate). The amount of radiopacifying element is between 1% and 20%
by weight, relative to the solid phase, preferably between 2% and 5% by
weight, relative to the solid phase. The solid phase may additionally
comprise one or more pharmacologically active substances. The method for
its preparation consists in preparing the radiopacifying material by
coating the metal particles with a layer of a polymer which is compatible
with the matrix and exhibits oxygen barrier properties such that said
layer does not dissolve completely in the liquid phase so as to keep its
oxygen barrier properties at least partly unchanged.