Protein carbonylation associated with nickel liberation in orthodontic gingival overgrowth.

Objective: To determine nickel levels and their impact on protein carbonylation in gum samples from patients with gingival overgrowth by orthodontic treatment.

Design: A retrospective observational study with 33 patients divided into three groups. Group 1 patients with gingival overgrowth by orthodontic appliances; group 2 patients without gingival overgrowth but with a history of orthodontic treatment; group 3 patients without overgrowth and history of orthodontic appliances.