RESUMO
PURPOSE: The objective of this study was to compare the bonding strength between cement and an implant according to the cementing time. MATERIALS AND METHODS: The two types of cement used were CMW(R) 1 and 3 (Depuy Ltd., Blackpool, UK). Plastic molds containing CMW(R) 1 were pressed onto metal blocks at 2, 4, 5 or 6 minutes after mixing the cement, while molds containing CMW(R) 3 were pressed onto blocks at 3, 5, 6 or 7 minutes after mixing the cement. Tensile strength was tested with using an Instron Model 8874 (Instron Corp., Canton, MA, USA). Tensile strengths were compared using the Kruskal-Wallis test and the Mann-Whitney U test. RESULTS: The strongest bonding strengths for the tensile load were at 2 minutes post-mixing for CMW(R) 1, and at 3 minutes post-mixing for CMW(R) 3. The strength rapidly decreased after 5 minutes for CMW(R) 1 and after 6 minutes for CMW(R) 3. CONCLUSION: This study suggests that the risk of loosening between cement and an implant is likely to be minimized by the surgical technique that considers the bonding strength according to time.