[Dental materials--problem substances in allergologic diagnosis? II: Patch test diagnosis and relevance evaluation of selected dental material groups].

The problems in patch testing and relevance evaluation as well as the practical consequences are discussed for the most important groups of dental materials (DM). These include metal alloys: amalgam with a low allergy prevalence; palladium salts showing a high correlation with nickel allergy but a low one with metallic palladium or alloys; the widespread allergen nickel is most relevant when dealing with nickel containing DM-alloys that are not corrosionresistant; gold salts with widely differing test results and limited benefit to detect genuine gold intolerance. Among synthetic resins methylmethacrylate is the most important allergen because of the high frequency of exposition. With composite materials and other methacrylates, both cross reactions and active sensitization should be kept in mind. Relevant reactions due to additives are rare; positive benzoylperoxide tests should be interpreted very critically. A number of DM may contain allergens of the etheric oils-colophonium - Perubalsam group. DM should be tested with standardized methods only. As the dental consequences may be expensive, interpretation of such test results demands utmost care and special experience.