[Amalgam and the toxicological risks of mercury. A review of the argument].

The employment of dental amalgam in the area of conservative dentistry, in spite of representing an excellent therapeutic solution, is today undergoing criticism more frequently than before because of the potential toxicity of mercury regarding hyman health and environmental salubrity. Mercury is a metal having the tendency to evaporate at ambient temperature and it is just the inhalation of its vapor the most common form of exposure to mercury for man. The absorption may also may also occur through food ingestion or accidental swallowing of metal particles coming from dental amalgam fillings. Mercury poisoning usually turns out to be a chronic process which causes its major toxic effects at the expense of digestive, excretory and neurocentral apparatuses. Several authors have studied mercury exposure on the working places, including in their investigation persons operating in the dentistry departments: they found high levels of mercury existing both in tissues and in biological fluids in people affected by exposure, frequently accompanied by symptoms of chronic intoxication. More recent studies, however, do not fully confirm such conclusions and exclude that coming into contact with mercury vapor on the working place may be in connection with an increase of mortality. Exposure to mercury from amalgam for the most part occurs through ingestion of amalgam particles abraded from restored surfaces, inhalation of vapors generated during dental restorative procedures and deglutition of saliva into which corrosion products have dissolved.(ABSTRACT TRUNCATED AT 250 WORDS)