Delayed and immediate hypersensitivity reactions associated with the use of amalgam

Hypersensitivity to the constituents of dental amalgam is uncommon. When it occurs it typically manifests itself as a lichenoid reaction involving a d elayed, type IV, cell-mediated hypersensitivity response. Rarely, a more ac ute and generalised response can occur involving both the oral mucosa and s kin. We describe two cases that illustrate the presentation and management of these two types of reaction.