Dental amalgam controversy cause harm in patients." Also, in the FDA final regulation on dental amalgam in 2009, the FDA recommended the product labeling of dental amalgam. The suggested labeling included: a warning against the use of dental amalgam in patients with mercury allergy, a warning that dental professionals use appropriate ventilation when handling dental amalgam, and a statement discussion of scientific evidence on dental amalgam's risks and benefits in order to make informed decisions amongst patient and professional dentists. The use of mercury in dental fillings is considered safe and effective in all countries practicing modern dentistry (see below). There are currently
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