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
Amalgam (dentistry) conservative preparation would be beneficial, composite is the recommended restorative material. These situations would include small occlusal restorations, in which amalgam would require the removal of more sound tooth structure, as well as in "enamel sites beyond the height of contour". For cosmetic purposes, composite is preferred when a restoration is required on an immediately visible portion of a tooth. Dental amalgam does not by itself bond to tooth structure. This was recognized as a shortcoming by early practitioners such as Baldwin. He recommended that the prepared cavity be coated with zinc phosphate cement just prior to filling with amalgam,