Amalgam (dentistry) and the American Society of Dental Surgeons (ASDS), the only US dental association at the time, forced all of its members to sign a pledge to abstain from using the mercury fillings. This was the beginning of what is known as the first dental amalgam war. The dispute ended in 1856 with the disbanding of the old association. The American Dental Association (ADA) was founded in its place in 1859, which has since then strongly defended dental amalgam from allegations of being too risky from the health standpoint. Amalgam has been used for many years for restorations, commonly known as
Inorganic chemistry based on their properties. Partly the classification focuses on the position in the periodic table of the heaviest element (the element with the highest atomic weight) in the compound, partly by grouping compounds by their structural similarities. When studying inorganic compounds, one often encounters parts of the different classes of inorganic chemistry (an organometallic compound is characterized by its coordination chemistry, and may show interesting solid state properties). Different classifications are: Classical coordination compounds feature metals bound to "lone pairs" of electrons residing on the main group atoms of ligands such as HO, NH, Cl, and CN. In modern coordination