Sodium amalgam Sodium amalgam Sodium amalgam, commonly denoted Na(Hg), is an alloy of mercury and sodium. The term amalgam is used for alloys, intermetallic compounds, and solutions (both solid solutions and liquid solutions) involving mercury as a major component. Sodium amalgam is often used in reactions as strong reducing agents with better handling properties compared to solid sodium. They are less dangerously reactive toward water and in fact are often used as an aqueous suspension. No particular formula is assigned to "sodium amalgam". NaHg and NaHg are well defined compounds. In sodium amalgams, the Hg-Hg distances are expanded to around 5 Å
Dental amalgam controversy condoned the use of dental amalgam. In 1855, Dr. J. Foster Flagg, a professor of dental pathology in Philadelphia, experimented with new mixtures of amalgam. In 1861, he presented his findings to the Pennsylvania Association of Dental Surgeons and, in 1881, he published his book, Plastic and Plastic Fillings (Figure 4). (Amalgam fillings were often called "plastic fillings" at the time.) The inevitable result of this affair was that silver amalgam was proven to be, "an excellent filling material," and expanded dentistry's, "ability to save teeth." Around the same time, John and Charles Tomes in England conducted research on the