Is nitinol biocompatible?
Nickel-titanium (Ni-Ti) alloys generally have good biocompatibility.
The surface of Ni-Ti alloys can form a passive oxide layer, primarily titanium dioxide (TiO 2), which helps prevent the release of potentially harmful nickel ions. This oxide layer reduces the risk of adverse reactions in the biological environment. In many medical applications, such as stents and orthodontic wires, Ni-Ti alloys interact well with biological tissues, showing that they can coexist with the body's physiological environment without causing a serious immune response or toxicity most of the time. However, in some cases, concerns about nickel ion release and potential allergic reactions remain, especially in patients allergic to nickel.