Dental amalgam controversy interviews with people claiming that their health problems were caused by amalgam fillings, and who have regained their health after replacing their amalgam fillings with a different material. Some scientific studies also reported that patients have been restored to health after having had their amalgam fillings replaced. However, these studies were heavily disputed at the time and the Norwegian Board of Health still maintain there is no scientifically proven connection between dental amalgam and health problems. In 1991, organized through the ministry of the environment, Norway began phasing out the use of most mercury-containing products (not limited to amalgam fillings
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