Nickel is one of the most common causes of
allergic contact dermatitis and produces more
allergic reactions than all other metals combined. Currently, several brands of
orthodontic wires are made of
nickel titanium alloy and potentially have a high enough
nickel content to provoke manifestations of
allergic reactions in the oral cavity. The objectives of this study were (1) to determine if standard orthodontic
therapy can sensitize patients to
nickel, and (2) to assess gingival response to
nickel-containing
orthodontic appliances in patients who are
nickel sensitive before treatment.
Nickel sensitivity patch tests were conducted to confirm
hypersensitivity to
nickel. Twenty-nine patients from the Division of
Orthodontics, Albert Einstein/Montefiore Medical Center were tested, ranging in age from 12 to 48 years. Of the 29 patients, there were 18 female and 11 males. Five of the patients had a positive
nickel patch test, a rate of 18.5%. The five patients that tested positive were all female, meaning that the overall rate for females was 27.7% (5:18). The five female patients sensitive to
nickel were followed monthly by intraoral photos and gingival and plaque index scores. The remaining patients began routine orthodontic
therapy and were retested 3 months into treatment to see whether sensitization occurred. Two patients converted from an initial negative patch test to a positive test. There may be a risk of sensitizing patients to
nickel with long-term exposure to
nickel-containing appliances as occurs in routine orthodontic
therapy.