The relation between electrochemical tests and in vitro evaluation of titanium alloy biocompatibility

In this paper, the electrochemical behaviour of the titanium and Ti‐6Al‐7Nb alloy in artificial saliva (Tani&Zucchi and Carter–Brugirard), ion release tests and in vitro biocompatibility of human osteoblasts (HOB) were studied. Titanium and its implant Ti‐6Al‐7Nb alloy present self‐passivation and very stable passive films in Tani&Zucchi artificial saliva of pH = 2.5; 5; 6.7; 9; the total quantity of ions released in the artificial saliva and corrosion rates are very low, proving a very good corrosion resistance and very low toxicity. In undoped and doped Carter–Brugirard saliva, the open circuit potentials have highly electropositive values, denoting passive state and good stability; the open circuit potential gradients, simulating the non‐uniformity of the saliva composition, show very low values, no danger for the implant integrity. The in vitro cytotoxicity of Ti‐6Al‐7Nb alloy was evaluated on the basis of cell morphology and cell viability. The results obtained revealed a high biocompatibility between HOB and Ti‐6Al‐7Nb alloy.