Corrosion of orthodontic devices.

A brief overview of the theory of corrosion and the formation of galvanic couples is presented, followed by a discussion of the metals and alloys used in the fabrication of orthodontic appliances and devices. Attention is paid to the factors that contribute to establishment of corrosion cells in the mouth. Although oral corrosion generally does not cause significant destruction of metal, it can elicit in patients adverse physiological responses such as local irritation and metal hypersensitivity. There are indications that orthodontic treatment may lower the incidence of nickel hypersensitivity. Destructive attack on orthodontic appliances does occur, however, when certain types of denture cleanser are used to clean appliances that contain soldered joints.