Nickel concentration in the saliva of patients with nickel-titanium orthodontic appliances.

Introduction: The purpose of this study was to examine whether nickel-titanium (Ni-Ti) archwires cause an increase of nickel concentration in the saliva of 18 orthodontic patients to estimate the possible risk of these archwires in patients who have nickel hypersensitivity.

Methods: Saliva samples were collected before orthodontic treatment, after placement of the bands and brackets, 2 weeks later and before placing the Ni-Ti archwires, immediately after placing the Ni-Ti archwires, 4 weeks after placing the wires, and 8 weeks after placing the wires.

Results: By using mass spectrometry, no statistically significant differences were found in the nickel concentrations in the samples taken without appliances, in those obtained 2 weeks after placement of the bands and brackets, and 4 and 8 weeks after placement of the archwires.