Dental amalgam controversy Dental amalgam controversy This discussion of the dental amalgam controversy outlines the debate over whether dental amalgam (the mercury alloy in dental fillings) should be used. Supporters claim that it is safe, effective and long-lasting while critics argue that claims have been made since the 1840s that amalgam is unsafe because it may cause mercury poisoning and other toxicity. Supporters of amalgam fillings point out that it is safe, durable, relatively inexpensive, and easy to use. On average, amalgam lasts twice as long as resin composites, takes less time to place, is tolerant of saliva or blood contamination during placement
Actinide chemistry Actinide chemistry Actinide chemistry (or actinoid chemistry) is one of the main branches of nuclear chemistry that investigates the processes and molecular systems of the actinides. The actinides derive their name from the group 3 element actinium. The informal chemical symbol An is used in general discussions of actinide chemistry to refer to any actinide. All but one of the actinides are f-block elements, corresponding to the filling of the 5f electron shell; lawrencium, a d-block element, is also generally considered an actinide. In comparison with the lanthanides, also mostly f-block elements, the actinides show much more variable valence. The