Nickel and cobalt hypersensitivity reaction before and after orthodontic therapy in children.

Nickel and cobalt are major components of alloys used in orthodontics. The objectives of this cross-sectional study was to determine the prevalence of a nickel hypersensitivity reaction before and after orthodontic treatment with conventional stainless steel brackets and wires. The total sample consisted of 82 patients (55 females, and 27 males) from the Orthodontic Department at the Faculty of Dentistry, Süleyman Demirel University. A patch test and a questionnaire were used to evaluate hypersensitivity to these metals. The statistical analysis was carried out using Fisher's exact X(2) (2 x 2) test. The prevalence of nickel allergy was found to be higher in females than males (14.55% in females, 0% in males), and the prevalence of cobalt allergy was found to be 9.76% (7.27% in females, 14.81% in males). Orthodontic treatment with conventional stainless steel alloys does not appear to have an allergenic effect on the gingival and oral health of the patient. A family history of an allergy to these metals or the use of metallic objects in contact with the skin do not characterize nickel and cobalt hypersensitivity. This suggests orthodontic therapy with conventional stainless steel appliances does not initiate or aggravate a nickel hypersensitivity reaction. There was no association between the before treatment and after treatment to a nickel and cobalt hypersensitivity reaction.