Abstract
Acrylic bone cement is self-curing cement comprising
of liquid and powder component of methyl
methacrylate (MMA). It has been used extensively
in orthopedics; however, adverse effects were
associated with its use. Hence we investigated in
this paper the possibility of new cement utilizing
methacrylates with lower toxicity than MMA.
LD50s of candidate monomers were determined
with administration to the medullary cavity of the
rat’s femur. 2-Ethylhexyl methacrylate (EHMA) and
trimethylolpropane trimethacrylate (TMP) demonstrated
greater LD50 values of 187 mg/kg and 380
mg/kg, respectively, than MMA (108 mg/kg); they
were selected as the liquid components of the
new cement. The copolymer of EHMA and cyclohexyl
methacrylate was then selected as the powder
component. With this combination, we developed
the new cement (EHMA cement). Temperature
rise during polymerization of EHMA cement was
9°C–13°C, which was signifi cantly lower than that
of conventional cement. The compression strength
of the polymerized EHMA cement was 57 MPa without
TMP, and 67 MPa with TMP (15 wt%). Thus we
concluded that new EHMA cement was slightly
inferior in the compression strength than the conventional
cement. However, it was characterized by
the low toxicity of utilized monomers and the low
temperature rise during polymerization.
