Mechanical and thermal properties of polymethylmethacrylate bone cement composites incorporated with hydroxyapatite and glass-ceramic fillers

A new bioactive glass-ceramic based on the Na ₂O-CaO-SiO ₂-P ₂O ₅ glass system was used as bioactive filler in commercial polymethylmethacrylate (PMMA) bone cement; (PALACOS ^® LV). The results of this newly fabricated glass-ceramic were compared with those of hydroxyapatite (HA) filler. PMMA bone cement containing 0, 4, 8, 12, or 16 wt % glass-ceramic and HA were prepared. The effects of bioactive fillers and different filler loadings on mechanical and thermal properties were evaluated. Results show that flexural strength decreased, while flexural modulus increased as filler loading was amplified. Fracture toughness was also observed. Results of thermogravimetric analysis indicate that the thermal stability of the cement composites increased with increasing glass-ceramic and HA contents. Dynamic mechanical analysis shows that the addition of glass-ceramic fillers resulted in an increase in storage modulus and T _g. Apatite morphology was observed on the surface of the glass-ceramic, GCBC4, and GCBC8 after a bioactivity test.