Toxicity of Metal Ions Selectively Leached From TiNi Shape Memory Alloys Determined by Escherichia Coli DH5á

This study investigated the toxicity of the metal ions selectively leached from TiNi shape memory wires in Ringer's solution determined by Escherichia coli DH5α. Some TiNi wires were heat treated at 500^oC for different time intervals to obtain the effect of surface modification on the selectively leaching process. The concentrations and the toxicity of Ti and Ni ions were determined by atomic absorption spectroscopy and Probit dose-response model, respectively. Experimental results revealed that, after selectively leached in Ringer's solution for 30 days, the concentration of Ni ion was determined as 0.57 ppm for TiNi wires heated at 500^oC for 12 h. On the other hand, the concentration of Ni ion was extremely low for TiNi wires without heat treatment. Ti ion selectively leached from TiNi wires with or without heat treatment was almost undetectable in this study. Both the Ni and Ti ions selectively leached from TiNi wires in Ringer's solution for 30 days did not cause toxicity or inhibit effect on the growth of Escherichia coli DH5α.