This study aimed to investigate a possible connection between removal of dental amalgam restorations supported by antioxidant therapy and indicative changes of clinical chemistry parameters. A group of 24 patients, referred for complaints related to amalgam restorations, underwent a removal of their amalgams. All patients were treated with antioxidants (vitamin B-complex, vitamin C, vitamin E, and sodium selenite). An age- and sex-matched control group of 22 individuals was also included. The mercury (Hg) and selenium (Se) concentration in plasma, Hg concentration in erythrocytes, and 17 clinical chemistry variables were examined in three groups: patients before amalgam removal (Before), patients after amalgam removal (After), and control individuals (Control). The Hg and Se values decreased (p < 0.05) in plasma, and the Hg concentration decreased (p < 0.05) in erythrocytes after amalgam removal. The variables serum lactate dehydrogenase (serum LDH) and serum sodium differed significantly both when comparing Control with Before (p < 0.01) and Before with After (p < 0.01). The variables white blood cell count (WBC), blood neutrophil count, blood eosinophil count, blood basophil count, blood lymphocyte count, blood monocyte count, serum potassium, and serum creatinine differed in the Before/After test (p < 0.05). Multivariate statistics (discriminant function analysis) could separate the groups Before and After with only one misclassification.

The objective of this study was to determine the concentration changes of 13 elements in erythrocytes and plasma after the removal of dental amalgam and other metal alloys. Blood samples from 250 patients were collected, separated into erythrocytes and plasma, and analyzed by inductively coupled plasma-mass spectrometry. The 250 patients were divided into 3 groups (Negative, Zero, and Positive) depending on their estimation of quality of life in an earlier study. Magnesium in plasma, selenium and mercury in plasma, and erythrocytes showed decreased concentrations after amalgam removal in all groups (p < 0.05). Titanium in plasma, copper in plasma, and erythrocytes and zinc in plasma exhibited decreased concentrations after amalgam removal in the Negative and Positive groups (p < 0.05). Silver in plasma and gold in erythrocytes decreased in the Zero and Positive groups after amalgam removal (p < 0.05). Copper in erythrocytes and silver and gold in plasma showed higher concentrations after amalgam removal in the Negative compared to the Positive group (p < 0.05), suggesting that patients in the Negative group excrete metals slowly. Moreover, the cobalt levels in plasma were lowest in the Negative group and only this group showed a significant increase in vitamin B12 levels in blood after amalgam removal.

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Corrosion and wear of dental amalgam may be associated with unexpectedly high levels of endogenous exposure to heavy metals. According to WHO, the resulting uptake of mercury exceeds that from all other sources in persons not occupationally exposed (WHO 1991) and a daily uptake level of 100 μg has been reported (Barregard et al. 1995). Due to the distribution patterns of mercury, standard blood and urine analyses give meager information on the response of the organism to this exposure. We here present data from nuclear microscopy analysis of neutrophil granulocytes (short-lived cells in the immune system cascade) in peripheral blood. Blood samples were drawn from patients suffering from possible side effects from dental amalgam. Their symptoms resembled those of the Chronic Fatigue Syndrome (Fukuda 1994), and the onset or intensity of the symptoms were related to occasional increased exposure to dental amalgam e.g., unprotected placing/drilling of the material. Data showed profound derangement of several cellular trace elements in the patient group and in some cases the substitution of mercury for zinc in the nuclear area. This supports the contention that systemic side effects from dental amalgam may occur. Venous blood samples were drawn from a cohort of Caucasian patients (n = 25) with a chronic debilitating illness, possibly related to the exposure from dental amalgam, and cell preparations were done as previously described (Johansson 1984, Lindh 1997). The same procedure was performed on blood samples from an age- and sex-matched healthy control group (n = 22) with similar numbers of amalgam fillings. A freeze-dried monolayer preparation of neutrophil granulocytes from each subject was investigated by means of nuclear microscopy (Zidenberg-Cherr). Thirty cells from each subject were analyzed in a subsequent manner and means and variances of the elemental concentrations of calcium (Ca), manganese (Mn), iron (Fe), zinc (Zn), and mercury (Hg) were calculated. In addition, the intracellular distribution of zinc and mercury was investigated in a few cells from both patients and controls by means of a nuclear microscopy elemental mapping technique. Cells with mercury levels above the detection limit (0.5 μg/kg dry weight) were investigated as well as cells with no detectable mercury.