Abstract
Palladium is a metal that is used as alloying metal for dental crowns and bridges. This thesis focusses on the possible impact of oral exposure to this metal on the immune system, and allergy in particular.
An alternative skin test allergen for diagnosing palladium allergy is introduced: (di)sodium tetrachloropalladate (Na2PdCl4). This test allergen was found to be more sensitive than the commonly used palladium(di)chloride (PdCl2). Using the new test allergen the prevalence of palladium sensitization increased considerably, and reached levels comparable to those of nickel (European multicentre study [n=1651]). Thus, usage of only PdCl2 in skin tests is advised against, since palladium sensitization/allergy will be underestimated due to false negative test results.
Also laboratory in vitro tests, based either on Pd-induced proliferation or cytokine production, performed better with the new test allergen Na2PdCl4¬. Here, clinical allergy was best reflected by type-2 cytokine (IL-5, IL-13) production. Whereas skin testing provides the most sensitive parameter, in vitro tests can provide useful complementary data in the diagnostic work-up process.
Further attention was paid to individual patient complaints in relation to sensitization and exposure to (distinct) dental restorative alloys. Mutual strong associations were found between (i) exposure to (palladium-based) dental crowns, (ii) sensitization to both palladium and nickel, and (iii) presence of oral disease and a history of metal allergic contact dermatitis. Local symptoms, like non-plaque related gingivitis, were not always reflected by true allergy, but could also be due to innate immune mechanisms. Therefore, the use of nickel- and palladium-based alloys in dental restorations should be minimized.
An alternative skin test allergen for diagnosing palladium allergy is introduced: (di)sodium tetrachloropalladate (Na2PdCl4). This test allergen was found to be more sensitive than the commonly used palladium(di)chloride (PdCl2). Using the new test allergen the prevalence of palladium sensitization increased considerably, and reached levels comparable to those of nickel (European multicentre study [n=1651]). Thus, usage of only PdCl2 in skin tests is advised against, since palladium sensitization/allergy will be underestimated due to false negative test results.
Also laboratory in vitro tests, based either on Pd-induced proliferation or cytokine production, performed better with the new test allergen Na2PdCl4¬. Here, clinical allergy was best reflected by type-2 cytokine (IL-5, IL-13) production. Whereas skin testing provides the most sensitive parameter, in vitro tests can provide useful complementary data in the diagnostic work-up process.
Further attention was paid to individual patient complaints in relation to sensitization and exposure to (distinct) dental restorative alloys. Mutual strong associations were found between (i) exposure to (palladium-based) dental crowns, (ii) sensitization to both palladium and nickel, and (iii) presence of oral disease and a history of metal allergic contact dermatitis. Local symptoms, like non-plaque related gingivitis, were not always reflected by true allergy, but could also be due to innate immune mechanisms. Therefore, the use of nickel- and palladium-based alloys in dental restorations should be minimized.
| Original language | English |
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| Qualification | PhD |
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| Award date | 23 Jan 2015 |
| Publication status | Published - 2015 |