[Studies on the allergenic potential of palladium alloys]

Epicutaneous tests with test solutions of the European standard series and palladium chloride (1%) were performed in 486 patients of the University Hospital for Dermatology in Aachen. 17.9% of the patients exhibited Ni, 8.6% Co, 7.4% Pd and 4.1% Cr allergy. In 18 of 36 patients with a positive patch test reaction a further epicutaneous and epimucosal testing with metallic plates of pure palladium and a palladium alloy was performed. In 34 cases a positive skin reaction to palladium chloride was combined with a positive skin reaction to nickel sulphate. Only in one case was it possible to demonstrate an allergic reaction to a palladium metallic plate, which was tested additionally in artificial saliva. The results show that a dental alloy envisaged for use should be tested in an epicutaneous test, if the patient shows a positive reaction to the metallic salt solution. In case of positive patch tests to nickel sulphate, dental palladium alloys should not be used as an alternative unless sensitivity to palladium has been tested.