Hazardous Effects of Metallic Mercury

Over the past two or three decades, there has been an increasing awareness of the hazards inherent in the use of mercury in dentistry. All aspects of handling the mercury should be given attention. Many potential sources of mercury exposure exist in a dental office. Sources include: accidental spills, poor mercury hygiene, manual mulling to excess mercury from freshly mixed amalgam, mechanical amalgamators, ultrasonic amalgam condensors, failure to use high-vacuum suction while removing old amalgam restorations, and improper dry heat sterilization of amalgam contaminated instruments. Atmospheric mercury vapor resulting from a spill of free mercury is a major cause of contamination in the dental office environment. Occupational exposure to mercury is known to have toxic effects on a wide variety of systems. Inhalation of mercury is a major cause of mercury toxication and will cause severe pulmonary damage and renal injury, and central nervous system disturbances. Many nonspecific signs and symptoms also may occur, including weakness fatigue, anorexia, insomnia and gastrointestinal disturbances. Every dental clinic should follow the proper procedures for handling of mercury to reduce the hazard of contamination.