In vitro biocompatibility and ageing of 3Y-TZP/CNTs composites

The intrinsic brittleness of Tetragonal Zirconia Polycrystalline (TZP) materials has been the major barrier for their use in biocompatible orthopedic implants. Purpose of the current paper was to demonstrate that the material׳s toughness/hardness could be significantly improved with addition of carbon nanotubes (CNTs) to monolithic TZP. To verify possible application of the composites as implants, biocompatible responses of 3Y-TZP/CNTs was clarified in comparison with 3Y-TZP. The vitality, mineralization, and attachment status of osteoblast cells were studied by performing in vitro tests such as MTT assay, ALP assay, and SEM, respectively. Low-temperature degradation through 20 h of heat treatment at 134 °C and 3 bar was studied to determine lifespan of the composites under humid atmosphere of human body conditions. Results showed suitable biocompatibility and negligible amount of low-temperature degradation. The synthesized TZP/CNTs composites, as a result, can be realized as adequate candidates for use in bone implants owing to their proper biocompatibility as well as a prolonged resistance against failure corroborating prominent mechanical properties compared to pure zirconia.