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
Chemical element or an electrophile; similarly "Nu" denotes a nucleophile. "L" is used to represent a general ligand in inorganic and organometallic chemistry. "M" is also often used in place of a general metal. At least two additional, two-letter generic chemical symbols are also in informal usage, "Ln" for any lanthanide element and "An" for any actinide element. "Rg" was formerly used for any rare gas element, but the group of rare gases has now been renamed noble gases and the symbol "Rg" has now been assigned to the element roentgenium. Isotopes are distinguished by the atomic mass number (total protons and