Barregard L, Sallsten G & Jarvholm B. People with high mercury uptake from their own dental amalgam fillings. Occup Environ Med 52:124-128 (1995)

"Objectives - To describe people with high mercury (Hg) uptake from their amalgam fillings, and to estimate the possible fraction of the occupationally unexposed Swedish population with high excretion of urinary Hg. Methods - Three case reports are presented. The distribution of excretion of urinary Hg in the general population was examined in pooled data from several sources. Results - The three cases excreted 23-60 ug of Hg/day (25-54 ug/g creatinine), indicating daily uptake of Hg as high as 100 ug. Blood Hg was 12-23 ug/l, which is five to 10 times the average in the general population. No other sources of exposure were found, and removal of the ammalgam fillings resulted in normal Hg concentrations. Chewing gum and bruxism were the probable reasons for the increased Hg uptake. Extrapolations from data on urinary Hg in the general population indicate that the number of people with urinary excretion of ,,50 ug/g creatinine could in fact be larger than the number of workers with equivalent exposure from occupational sources. Conclusion - Although the average daily Hg uptake from dental amalgam fillings is low, there is a considerable variation between people; certain people have a high mercury uptake from their amalgam fillings."

Begerow J, Zander D, Freier I & Dunemann L. Long-term mercury excretion in urine after removal of amalgam fillings. Int Arch Occup Health 66:209-212 (1994)

Abstract: "The long-term urinary mercury excretion was determined in 17 28- to 55-year-old persons before and at varying times (up to 14 months) after removal of all (4-24) dental amalgam fillings. Before removal the urinary mercury excretion correlated with the number of amalgam fillings. In the immediate post-removal phase (up to 6 days after removal) a mean increase of 30% was observed. Within 12 months the geometric mean of the mercury excretion was reduced by a factor of 5 from 1.44 ug/g (range: 0.57-4.38 ug/g) to 0.36 ug/g (range: 0.13-0.88 ug/g). After cessation of exposure to dental amalgam the mean half-life was 95 days. These results show that the release of mercury from dental amalgam contributes predominantly to the mercury exposure of non-occupationally exposed persons. The exposure from amalgam fillings thus exceeds the exposure from food, air and beverages. Within 12 months after removal of all amalgam fillings the participants showed substantially lower urinary mercury levels which were comparable to those found in subjects who have never had dental amalgam fillings. A relationship between the urinary mercury excretion and adverse effects was not found. Differences in the frequency of effects between pre- and the post-removal phase were not observed."

Berglund A. Estimation by a 24-hour Study of the Daily Dose of Intra-oral Mercury Vapor Inhale after Release from Dental Amalgam. J Dent Res 69(10):1646-1651 (1990)

Abstract: "The difficulties associated with estimations of daily doses of inhaled mercury vapor released from dental amalgam are considerable. Existing data are often unreliable, especially if they are based on a single or a small series of samples of intra-oral concentrations of mercury vapor before, during, and after chewing stimulation. In the present paper, the aim was to obtain a more representative estimation of the daily dose of mercury vapor inhaled from amalgam fillings by measurements of amounts of mercury vapor released in the oral cavity during 24 h, under conditions that were as normal as possible. A series of measurements was carried out on each of 15 subjects, with at least nine occlusal surfaces restored with dental amalgam, and on five subjects without any amalgam restorations. The subjects had to dfollow a standarized schedule for 24 h, whereby they ate, drank, and brushed their teeth at pre-determined time periods. The amount of mercury vapor released per time unit was measured at intervals of 30-45 min by means of a measuring system based on atomic absorption spectrophotometry. None of the subjects was professionally exposed to mercury, and all their amalgam fillings were more than one year old. Study casts were made for each subject, and the area of the amalgam surfaces was mesured. Samples of urine and saliva were analyzed so that values for the mercury concentrations and the rate of release of mercury into saliva could be obtained. The average frequency of fish meals per month was noted. The daily release of elemental mercury from dental amalgam was corrected for retention of inspired mercury vapor and for oral-to-nasal breathing ration. The estimated average daily dose of mercury vapor inhaled from the amalgam restorations was 1.7 ug, i.e., about 1 % of the dose obtained from a TLV exposure of 50 ug Hg/m3 air. The treshold limit value (TLV) of a substance is the airborne concentration to which nearly all workers can be exposed eight hours a day, five days a week for a prolonged periods without suffering adverse health effects (American Conference of Goverment Industrial Hygienists: Threshold Limit Values and Biological Exposure Indices for 1985-1986, Cincinnati, 1985)"

Berglund A & Molin M. Mercury vapor release from dental amalgam in patients with symptoms allegedly caused by amalgam fillings. Europ J Oral Sci 104(1):56-63 (1996)

Abstract: "The aim of this study was to determine whether a group of patients with symptoms, self-related to their amalgam restorations, experienced an exposure to mercury vapor from their amalgam restorations that reached the range at which subtle symptoms have been reported in the literature. Furthermore, the aim was to determine whether the mercury exposure for these patients was significantly higher than for controls with no reported health complaints. The symptom group consisted of 10 consecutively selected patients from a larger group, referred by their physicians for investigation into any correlation between subjective symptoms and amalgam restorations, The control group consisted of 8 persons with no reported health complaints. The intra-oral release of mercury vapor was measured between 7:45 a.m, and 9:00 p.m, at intervals of 30-45 min, following a standardized schedule. The mercury levels in plasma, erythrocytes, and urine were also determined. The calculated daily uptake of inhaled mercury vapor, released from the amalgam restorations, was less than 5% of the daily uptake calculated at the lower concentration range given by the WHO (1991), at which subtle symptoms have been found in particularly sensitive individuals. The symptom group had neither a higher estimated daily uptake of inhaled mercury vapor, nor a higher mercury concentration in blood and urine than the control group. The study provides no scientific support for the belief that the symptoms of the patients examined originated from an enhanced mercury release from their amalgam restorations."

Also make sure to read these books: Poison in Your Teeth: Mercury Amalgam (Silver) Fillings...Hazardous to Your Health! and Mercury Detoxification by Tom McGuire