Improvement of Mechanical Properties of Oligomer-modified Acrylic Bone Cement with Glass-fibers

Some mechanical properties of oligomer-modified acrylic bone cement with glass-fibers were studied. Under wet environments, oligomer-filler forms a porous structure in the acrylic bone cement. Test specimens were manufactured using commercial bone cement (Palacos® R) with different quantities of an experimental oligomer-filler (0–20 wt%), and included continuous unidirectional E-glass fibers (l=65 mm) or chopped E-glass fibers (l=2 mm). The specimens were either tested dry, or after being immersed under wet environments for one week. The three-point bending test was used to measure the flexural strength and modulus of the acrylic bone cement composites (analysis with ANOVA). A scanning electron microscope (SEM) was used to examine the surface structure of the acrylic bone cement composites. Using continuous glass-fiber reinforcement, the dry flexural strength was 145 MPa and modulus was 4.6 GPa for the plain bone cement. For the test specimens with 20 wt% of oligomer-filler and continuous unidirectional glass-fibers, the dry flexural strength was 118 MPa and modulus was 4.2 GPa, whereas the wet flexural strength was 66 MPa and modulus was 3.0 GPa. The results suggest that the reduced flexural properties caused by the porosity of oligomer-modified bone cement can be compensated with glass-fiber reinforcement.