Investigation of mechanical and tribological properties of bone cement by nano-indentation and nano-scratch experiments

The mechanical and tribological properties of PMMA-based bone cement (CEMEX RX, TECRES Company, Italy) were measured using nano-indentation and nano-scratch tests. The polymer samples were prepared using two different mixing methods i.e., hand mixing and vacuum mixing. Cubic CEMEX RX specimens were produced and the nano-indentation and nano-scratch tests were performed on both the hand-mixed and the vacuum-mixed specimens by a nano-indenter setup and atomic force microscopy (AFM) observation. The values of Young's modulus, hardness and wear resistance obtained on the hand-mixed and the vacuum-mixed cements were compared. The results indicate that the vacuum-mixed cement has better mechanical and tribological properties compared with the hand-mixed one. Since the nano-indentation and the nano-scratch test methods need less sample material, decrease costs and obtain reliable results, they can be considered as suitable techniques for determination of the mechanical and tribological properties of bone cements.