Low Monomer Content, High Strength Composite Bone Cements

Abstract

The study aim was development of composite bone cements with lower monomer content, viscosity and modulus but a higher conversion and strength than the commercial composite Urethane dimethacrylate (UDMA), Triethylene glycol-dimethacrylate (TEGDMA) and Hydroxyethyl methacrylate (HEMA) were combined with 0.5 or 1 wt% initiator / activator. This monomer was subsequently combined with 70-80 wt% glass filler. FTIR was used to assess reaction inhibition time and half-life in addition to final monomer conversion at 26 and 37 °C. Biaxial flexural strength and modulus were measured after 24 hours in water or simulated body fluid at 37 °C and compared with that of Cortoss (Commercial Composite bone cement). Results showed that even with 1/3 rd less monomer content, the experimental composites could be mixed through a finer syringe tip than Cortoss. Cure rate and final conversion were increased by raising temperature, initiator and activator concentration. Strength and modulus were raised by increasing initiator concentration. All experimental formulations had greater monomer conversion and strength than Cortoss and those with low initiators also had lower modulus. The experimental materials show promise as an alternative bone cements.