Nickel containing alloys have been widely used in the provision of various forms of dental care. Furthermore, these alloys are commonly used in orthodontic applications, such as brackets, arch wires, bands, springs and ligature wires. Nickel containing alloys are almost along with the whole process of orthodontic treatment. As materials used for human body, biosafety of dental material is now a fundamental requirement of successful clinical behavior in oral cavity. Nowadays, corrosion and the potential toxicity of nickel containing alloys has been taken seriously with the developing of health awareness. This article reviewed recent studies of the biosafety of nickel containing alloys, the variables included the release of nickel ion from alloys, the sensitization, cytotoxicity, the carcinogenecity and the adverse reactions to other organs of nickel containing alloys.
