Mercury free dentistry Many people have metal fillings in their mouths, called dental amalgam fillings, which contain 50% mercury. According to The World Health Organisation in 1991 the major exposure to mercury is from dental amalgam in the form of mercury vapour. The mercury transfer to human tissues accumulates with time and presents a health threat. The amount of mercury vapour released is increased when other metals are present in the mouth next to the amalgam fillings. When dissimilar metals are placed in the oral cavity they exert a battery-like effect because of the electroconductivity of the saliva. The electrical current causes metal ions to go into a solution at a much higher rate, thereby increasing the exposure to mercury vapour and mercury ions many fold. The Department of Health in 1998 advised that exposure to mercury vapour is greatest during placement or renewal of amalgam.		Once the drill touches the filling the temperature increases immediately vapourising the mercury component of the alloy. Although we are all at risk during these procedures the Department only advised pregnant women to avoid such procedures because of the possibility of mercury vapour crossing the placenta. At Integrated Dentalcare we take great care to protect all our patients from additional exposure to mercury. As a result we do not use any mercury-based materials.