The supposed dangers of dental amalgam have been much in the news recently - amalgam has been blamed for mercury poisoning and other systemic disease. Dental materials contain several toxic components, including carcinogenic and teratogenic components and allergens, and, although they are manufactured to be inert and biologically inactive, clearly they may release some elements into the mouth. Despite these potential problems decades of worldwide clinical experience and research show that side effects to dental material are rare.

Side effects are estimated to occur at a frequency of between 1 in 1000 to 1 in 10 000 treatments involving restorative materials.1 Most reactions are mild, but severe allergic reactions occur rarely. The typical allergic response to dental materials is a delayed contact hypersensitivity reaction (type IV), which can be initiated by minute amounts of the allergen in sensitised individuals. Toxic reactions, on the other hand, are dose dependent. Minute amounts are released from dental materials. Therefore, allergic reactions are by far the most common.

Fluorides used to prevent dental caries can, like most drugs, be …