title: Sensitization to palladium and nickel in Europe and the relationship with oral disease and dental alloys.
abstract: BACKGROUND
  The role of palladium and nickel sensitization in oral disease and dermatitis is not fully understood.
  
  
  OBJECTIVE
  To investigate whether sensitization to these metals was associated with exposure to dental alloys and oral and skin complaints/symptoms in a European multicentre study.
  
  
  METHODS
  In six dermatology clinics, patch tests with palladium (3% Na2 PdCl4 ; Pd = 102.0 µmol/g) and nickel (5% NiSO4 .6H2 O; Ni = 190.2 µmol/g) were performed in consecutive patients, and patients' characteristics were collected with a questionnaire and a clinical investigation.
  
  
  RESULTS
  In total, 906 patients were included, of whom 24.3% reacted to palladium and 25.2% to nickel. The rate of monosensitization was 6-7% for both metals. Palladium sensitization (as opposed to no sensitization to both metals) was associated with exposure to dental crowns [odds ratio (OR) 2.0], skin reactivity to metals (OR 2.8), oral lichenoid lesions (OR 4.7), xerostomia (OR 7.3), and metal taste (OR 20.7), but not with eczema, stomatitis, or oral burning sensation. Additionally, xerostomia (OR 8.7) and metal taste (OR 4.6) were associated with sensitization to both metals.
  
  
  CONCLUSIONS
  Clinically, it is important for palladium-sensitized patients to undergo an oral examination, with particular attention to the presence of/exposure to dental crowns. In the case of metal contact allergy, exposure to dental crowns could play a role.
authors.affiliation: Department of Dental Materials Science, Academic Centre for Dentistry Amsterdam, University of Amsterdam and VU University Amsterdam, Gustav Mahlerlaan 3004, 1081 LA, Amsterdam, The Netherlands.
authors.forename: Joris
authors.initials: J
authors.lastname: Muris
authors.forename: An
authors.initials: A
authors.lastname: Goossens
authors.forename: Margarida
authors.initials: M
authors.lastname: Gonçalo
authors.forename: Andreas J
authors.initials: AJ
authors.lastname: Bircher
authors.forename: Ana
authors.initials: A
authors.lastname: Giménez-Arnau
authors.forename: Caterina
authors.initials: C
authors.lastname: Foti
authors.forename: Thomas
authors.initials: T
authors.lastname: Rustemeyer
authors.forename: Albert J
authors.initials: AJ
authors.lastname: Feilzer
authors.forename: Cornelis J
authors.initials: CJ
authors.lastname: Kleverlaan
mesh_terms: D003430:Cross-Sectional Studies; D003442:Crowns / Q000009:adverse effects*; D003722:Dental Alloys / Q000009:adverse effects*; D017449:Dermatitis, Allergic Contact / Q000175:diagnosis / Q000453:epidemiology* / Q000209:etiology; D005060:Europe; D005260:Female; D006801:Humans; D017676:Lichen Planus, Oral / Q000453:epidemiology; D008297:Male; D018777:Multiple Chemical Sensitivity / Q000453:epidemiology; D009532:Nickel / Q000009:adverse effects*; D010165:Palladium / Q000009:adverse effects*; D010328:Patch Tests; D015995:Prevalence; D011795:Surveys and Questionnaires; D013651:Taste Disorders / Q000453:epidemiology; D014987:Xerostomia / Q000453:epidemiology
chemical_list: D003722:Dental Alloys; D010165:Palladium; D009532:Nickel
keywords: allergic contact dermatitis; cross-reactivity; dental alloys; epidemiology; metals; nickel; oral disease; oral lichenoid lesion (OLL); palladium