Effect of nickel and chromium on gingival tissues during orthodontic treatment: a longitudinal study.

AIM: To determine the influence of chromium and nickel concentrations in saliva and their effects on gingival tissues during orthodontic treatment. METHODS: Twenty orthodontic patients (10 males and 10 females), 17 to 20 years of age, were treated with fixed orthodontic appliances in the maxillary arch. Using atomic absorption spectrophotometer, the concentration of both metals was recorded during pretreatment, at 3 and 12 months into treatment, and 1 month after debonding. The depth of gingival crevice was recorded as well. RESULTS: After 3 months, 20% of females and 10% of males in this study showed allergic reaction in a form of gingivitis. This had disappeared by 1 month after appliance removal. CONCLUSION: While allergy to either nickel or chromium is not a serious medical problem, oral hygiene measures in at-risk patients should be optimal, with use of fluoride-free toothpaste and mouthrinse.