Role and control of mercury exposure in dental settings

ABSTRACT

Mercury is a metal with toxic and bio-accumulative characteristics. It has biogenic and anthropogenic origins. A neurotoxin and nephro-toxin, mercury exposure is mainly via inhalation, ingestion, and dermal absorption. The degree of toxicity hinges upon exposure route, frequency, dose level, nutritional status, individual susceptibility, and genetic predispositions. Mercury as an environmental hazard operates on a global scale with an end result of bio-concentration of methyl mercury in fish that is used for human consumption. As an industry, dentistry is one of the largest end-users of mercury. Dental amalgams have been used as filling material for over 150 years. However the risk of mercury exposure as an occupational risk is considered higher for dentists and dental workers than for patients with amalgam fillings. Although, Scandinavian countries are in the process of phasing out use of amalgam filling material, the WHO, American Dental Association [ADA] and the US Center for Disease Control, [CDC] support the use of dental amalgam to fill cavities. Specific risk control strategies for amalgam related occupational safety and environmental protection have been outlined and their implementation enforced through legislative measures in the developed nations. Amalgam waste management protocols are completely lacking in developing nations. The UN Environment Mercury Program, based on the fact that mercury exposure is a global problem, has recommended that the precautionary principle should be evoked to initiate international action in terms of policies that should be enforced through a variable mechanism, unique to each country