Creep properties of three low temperature-curing bone cements: A preclinical assessment

The mechanical characteristics of new bone cements should be assessed befor e these cements are released on the orthopedic market in great quantities. In this study, we present the deformational response of 3 relatively new, l ow-curing temperature bone cements (Cemex RX, Cemex System, and Cemex Isopl astic) to a dynamic compressive force in comparison to Simplex P bone cemen t. For this purpose, dynamic compressive creep tests were performed on cyli ndrical shaped specimens at a maximal load level of 20 MPa for a period of 250,000 cycles. The results showed that Cemex System and Cemex RX produced creep rates that were higher (20% and 30%, respectively) as compared to Sim plex P bone cement. The creep behavior of Cemex Isoplastic was very similar to that of Simplex P. It was concluded that although Cemex RX and Cemex Sy stem produced higher creep rates than Simplex P, these differences were not considered excessive. Hence, although other tests are required to assess t he safety and efficacy of these new cements, the dynamic creep properties u nder compression can be considered adequate for clinical use. (C) 2000 John Wiley & Sons, Inc.