Initial cytotoxicity of novel titanium alloys

We assessed the biological response to several novel titanium alloys that have promising physical properties for biomedical applications. Four commercial titanium alloys [Super‐TIX® 800, Super‐TIX® 51AF, TIMETAL® 21SRx, and Ti‐6Al‐4V (ASTM grade 5)] and three experimental titanium alloys [Ti‐13Cr‐3Cu, Ti‐1.5Si and Ti‐1.5Si‐5Cu] were tested. Specimens (n = 6; 5.0 × 5.0 × 3.0 mm3) were cast in a centrifugal casting machine using a MgO‐based investment and polished to 600 grit, removing 250 μm from each surface. Commercially pure titanium (CP Ti: ASTM grade 2) and Teflon® (polytetrafluoroethylene) were used as positive controls. The specimens were cleaned and disinfected, and then each cleaned specimen was placed in direct contact with Balb/c 3T3 fibroblasts for 72 h. The cytotoxicity [succinic dehydrogenase (SDH) activity] of the extracts was assessed using the MTT method. Cytotoxicity of the metals tested was not statistically different compared to the CP Ti and Teflon® controls (p > 0.05). These novel titanium alloys pose cytotoxic risks no greater than many other commonly used alloys, including commercially pure titanium. The promising short‐term biocompatibility of these Ti alloys is probably due to their excellent corrosion resistance under static conditions, even in biological environments. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2007