title: Nickel: periodontal status and blood parameters in allergic orthodontic patients.
abstract: BACKGROUND
  The aims of this study were to compare blood parameters and periodontal characteristics of orthodontic patients allergic to nickel with those of nonallergic patients and to determine the correlation between blood components and periodontal abnormalities.
  
  
  METHODS
  Ninety-six randomly selected patients participated in the study. After determining the prevalence of those allergic to nickel, 2 groups were formed: 16 allergic patients and 16 nonallergic patients. Allergies to nickel were diagnosed by using the patch test, periodontal conditions were determined by using the gingival index, and humoral characteristics were determined through a complete blood test, including the quantification of nickel in the blood and the immunoglobulin E level. Feces examinations were performed to control for parasitic infections. Periodontal evaluations were performed blindly. Statistical analysis included the unpaired t test, the Mann-Whitney test, and the Pearson and Spearman correlations (P ≤0.05).
  
  
  RESULTS
  Statistically significant differences between groups were found for bands (P = 0.001). There was no correlation between the concentration of nickel and immunoglobulin E level (P = 0.674, experimental group; P = 0.605, control group). However, there was a positive correlation between the gingival index and the number of bands (P = 0.05).
  
  
  CONCLUSIONS
  Nickel can have an influence over the periodontal status of allergic orthodontic patients, causing an increase in band quantification that was correlated to gingival index.
authors.affiliation: Deparment of Orthodontics, Vale do Rio Verde University, Três Corações, Brazil.
authors.forename: Camila Alessandra
authors.initials: CA
authors.lastname: Pazzini
authors.forename: Luciano José
authors.initials: LJ
authors.lastname: Pereira
authors.forename: Rodrigo Generoso
authors.initials: RG
authors.lastname: Carlos
authors.forename: Gustavo Eustáquio Brito Alvim
authors.initials: GE
authors.lastname: de Melo
authors.forename: Maria Aparecida
authors.initials: MA
authors.lastname: Zampini
authors.forename: Leandro Silva
authors.initials: LS
authors.lastname: Marques
mesh_terms: D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D002648:Child; D002858:Chromium Alloys / Q000009:adverse effects; D004804:Eosinophils / Q000473:pathology; D005243:Feces / Q000469:parasitology; D005260:Female; D005881:Gingiva / Q000473:pathology; D005884:Gingival Hemorrhage / Q000209:etiology; D006801:Humans; D006967:Hypersensitivity / Q000097:blood / Q000150:complications*; D056724:Immunity, Humoral / Q000276:immunology; D007073:Immunoglobulin E / Q000097:blood; D007958:Leukocyte Count; D018655:Lymphocyte Count; D008297:Male; D009000:Monocytes / Q000473:pathology; D009504:Neutrophils / Q000473:pathology; D009532:Nickel / Q000009:adverse effects* / Q000097:blood; D009967:Orthodontic Appliances / Q000009:adverse effects; D016910:Orthodontic Brackets / Q000009:adverse effects; D009971:Orthodontics, Corrective; D010328:Patch Tests; D010512:Periodontal Index; D055815:Young Adult
chemical_list: D002858:Chromium Alloys; D007073:Immunoglobulin E; D009532:Nickel