Dental amalgam controversy emissions. The WHO also points out that amalgam separators, installed in the waste water lines of many dental offices, dramatically decrease the release of mercury into the public sewer system. In the United States, most dental practices are prohibited from disposing amalgam waste down the drain. Critics also point to cremation of dental fillings as an additional source of air pollution, contributing about 1% of total global emissions. It is the position of the FDI World Dental Federation as well as numerous dental associations and dental public health agencies worldwide that amalgam restorations are safe and effective. Numerous other organizations
Real element formula_1, Every involution is strongly real. Furthermore, every element that is the product of two involutions is strongly real. Conversely, every strongly real element is the product of two involutions. If and formula_1 is real in formula_2 and formula_30 is odd, then formula_1 is strongly real in formula_2. The extended centralizer of an element formula_1 of a group formula_2 is defined as making the extended centralizer of an element formula_1 equal to the normalizer of the set The extended centralizer of an element of a group formula_2 is always a subgroup of formula_2. For involutions or non-real elements, centralizer and