R-curve characterizes the resistance to fracture of a propagating crack on a brittle material. Ceramic filler material can be added to the PMMA bone cement to improve its resistance to fracture of a propagating crack. The motivation of this study was to improve the fracture resistance of the composite bone cement by incorporating bioactive ceramic nanoparticles with the bone cement. The hypothesis of this study was that extrinsic toughening characteristics of composite cement affect bone-composite fracture toughness. Two specific objectives were achieved during the study: (1) the fracture properties of composite cements were evaluated using in-situ field emission scanning electron microscope (FESEM), (2) R-curve affects on the fracture toughness of composite cements were examined using in-situ FESEM based R-curve measurement techniques. ASTM standard bow tie single edge notch tension specimen was fabricated using commercial PolyMethylMethAcrylate (PMMA) bone cement, bone cement with MgO micro and nanoparticles. The in-situ FESEM SENT fracture tests were conducted on cement specimens at a speed of 1.1 (mu)m/sec. using Evex SEM tensile test stage. This study found that the initiation stress intensity factor of the CBC specimen was higher compared to MgO additives incorporated CBC specimen. Higher energy is required for CBC specimen compared to the composite CBC specimens to propagate crack up to failure. MgO particles contribute to the origin of voids in the cement structure which affect the structural integrity MgO incorporated PMMA bone cement.
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