Sodium amalgam sodium metal in mercury or the reverse. Sodium amalgams can be purchased from chemical supply houses. Since its introduction in the 1880s by students of Robert Bunsen, Julius Tafel and Hans Goldschmidt, sodium amalgam has also been used in organic chemistry as a powerful reducing agent, which is safer to handle than sodium itself. An example of its use is in the Emde degradation. A sodium amalgam is used in the design of the high pressure sodium lamp providing sodium to produce the proper color, and mercury to tailor the electrical characteristics of the lamp. Sodium amalgam is a by-product
Amalgam (dentistry) conservative preparation would be beneficial, composite is the recommended restorative material. These situations would include small occlusal restorations, in which amalgam would require the removal of more sound tooth structure, as well as in "enamel sites beyond the height of contour". For cosmetic purposes, composite is preferred when a restoration is required on an immediately visible portion of a tooth. Dental amalgam does not by itself bond to tooth structure. This was recognized as a shortcoming by early practitioners such as Baldwin. He recommended that the prepared cavity be coated with zinc phosphate cement just prior to filling with amalgam,