[Contact allergy caused by new dental impression materials].

In 1965 a new group of polymeric materials has been introduced into dentistry which is used for temporary crowns, bridges and impression materials. In handling it contact may occur with all components of these impression materials (Scutan, Impregum). Contact over a long period may lead to allergic contact dermatitis. Epicutaneous tests in three dentists and a technical assistant revealed that the catalysts of the impression materials are responsible for contact allergy. In experiments with guinea pigs the strong sensitization capacity of the catalysts could be demonstrated. Methyl-dichlorbenzolsulfonat (catalyst of Impregum) showed a stronger effect than methyl-p-toluolsulfonat (catalyst of Scutan). Besides their allergenic properties these substances also act as primary irritants. As these materials are widespread in dentistry more attention should be payed at the risk of hand eczemas in dentists and dental personnel caused by the catalysts of Impregum and Scutan.