People are exposed to mercury through mercury-contaminated food and drinking water, through inhalation of air containing mercury and through their amalgam fillings. As the exposure to mercury through the fillings is chronic, it can be significant over a longer period. The amount of mercury released from the fillings varies from person to person and depends on, among other things, the number and age of the fillings. Mechanical pressure, such as chewing and brushing teeth, and the consumption of acidic and hot drinks promote the release of mercury from the fillings.
With the mercury in saliva test the mercury exposure is measured via the amalgam fillings. To prevent the results from being affected by mercury from food or by additional mercury released when drinking hot or sour drinks or brushing teeth, the two hours prior to collecting the saliva samples should not be eaten or drunk and no teeth be polished. It is not recommended to do the test within 2 months after a visit to the dentist. The treatment may temporarily raise the mercury level.
Because more mercury is released from the amalgam fillings during chewing than during 'rest', two samples must be collected during the test: one in 'rest' and one during chewing. Assuming that on average 1 hour is chewed per day and 23 hours is not chewed, this can be done by using. the values found then the daily mercury exposure via the fillings are calculated.