Minor changes in serum levels of cytokines after removal of amalgam restorations

Mercury, silver and selenium in serum before and after removal of amalgam restorations: results from a prospective cohort study in Norway

OBJECTIVE

A prospective cohort study on changes of health complaints after removal of amalgam restorations was carried out at the request of the Norwegian Directorate of Health. The aim was to provide and evaluate experimental treatment to patients with health complaints attributed to dental amalgam fillings.

METHODS

Patients (n = 32) with medically unexplained physical symptoms (MUPS), which were attributed to dental amalgam restorations had all their amalgam restorations removed and replaced with other dental restorative materials. Samples of blood were collected before and 1 year after removal of the fillings, and concentration of inorganic mercury (I-Hg), methylmercury (MeHg), silver (Ag) and selenium (Se) in serum was determined by inductively coupled plasma-sector field mass spectrometry. The comparison groups (one with MUPS but without attribution to amalgam [n = 28] and one group of healthy individuals [n = 19]) received no treatment. The participants responded to questionnaires at baseline and at follow-up after 1 and 5 years.

RESULTS

Concentration of I-Hg and Ag in serum decreased significantly after removal of all amalgam restorations. Concentration of MeHg and Se in serum were not changed. Intensity of health complaints was significantly reduced after amalgam removal, but there were no statistically significant correlations between exposure indicators and health complaints.

CONCLUSIONS

Removal of all amalgam restorations is followed by a decrease of concentration of I-Hg and Ag in serum. The results support the hypothesis that exposure to amalgam fillings causes an increase of the daily dose of both I-Hg and Ag. Even though intensity of health complaints decreased after removal of all amalgam restorations there was no clear evidence of a direct relationship between exposure and health complaints. Trial registration: The project is registered at Clinicaltrials.gov (NCT01682278).

Dental Amalgams and the Incidence Rate of Arthritis among American Adults

This hypothesis-testing study evaluated the relationship between mercury (Hg)-based dental amalgams and arthritis diagnoses among adults in the United States (US). A total of 86 305 425 weighted-persons with ⩾1 dental amalgam filling surface (DAFS) (exposed group) and 32 201 088 weighted-persons with ⩾1 other dental filling surface (ODFS) (no DAFS, unexposed group) were examined in the 2015 to 2016 National Health and Nutritional Examination Survey (NHANES). All persons were 20 to 80 years-old with known demographic characteristics and arthritis status. Survey logistic regression and survey frequency modeling in SAS were employed with and without adjustment of covariates. The arthritis rate was significantly increased in the exposed group compared to the unexposed group in the unadjusted (7.68-fold) and adjusted (4.89-fold) models. Arthritis (per 10 000 weighted-person-years) was 6.0-fold significantly increased in the exposed group (6.2) compared to the unexposed group (1.06). A significant bimodal dose-dependent relationship between DAFS and arthritis rate was observed. The arthritis rate increased with increasing DAFS (peak among persons with 4-7 DAFS) and, subsequently, decreased among those with >6 DAFS. A significant decrease in arthritis rate among persons with >13 DAFS as compared to those persons with 4 to 7 DAFS was observed. A significant association between DAFS and arthritis risk and a dose-dependent DAFS associated immune-stimulation/immune-suppression with arthritis risk were observed. An estimated additional $96 835 814 US dollars (USD) are spent on annual medical costs and $184 797 680 USD are lost in annual wages from reported new onset arthritis attributably associated with DAFS (annual total cost = $281 633 494 USD).

Psychological symptoms and self-image of patients with complaints attributed to dental restorative materials

OBJECTIVES

The aim was to study self-image and the level of psychological symptoms in patients with symptoms attributed to their dental restorative materials.

MATERIALS AND METHODS

A questionnaire containing questions regarding dental and medical history was answered by 257 participants, one group with local oral symptoms only (LSO), and one group with multi-symptoms (M-S). A reference group was randomly selected from a research database at the Department of Psychology, Umeå University, Sweden. The self-image was assessed using the Structural Analysis of Social Behavior (SASB). Psychological symptoms such as somatization, depression, and anxiety were assessed using the Symptom Check List 90 (SCL-90) and the Global Severity Index (GSI) was used to determine the level of psychological symptoms.

RESULTS

SASB showed that the M-S group and the LSO-group scored significantly higher on the "spontaneous" and "positive self-image" than the reference group. In the SCL-90, the M-S group scored significantly higher than the LSO-group and the references on the somatization subscales. On depression, anxiety, and the GSI scale, the M-S group scored significantly higher than the reference group.

CONCLUSIONS

The two subgroups scored significantly higher on the SASB Spontaneous and Positive clusters which indicates that these patients have an excessively positive self-image, are very spontaneous and have an overconfidence in themselves compared to the reference group. In the M-S group there was a clear tendency to somatization, depression, and anxiety and they were more psychologically stressed than the reference group.

CLINICAL RELEVANCE

Among the patients with illness attributed to their dental materials, the M-S-patients had a significantly higher level of general psychological distress and somatization than the control group which may lead to mental stress.

Mercury exposure and health impacts in dental personnel

Based on toxicological, clinical, and epidemiological knowledge, the present paper reviews the status regarding possible deleterious health effects from occupational exposure to metallic mercury (Hg) in dental practice. Symptoms from the central nervous system are among the health problems that most often are attributed to Hg exposure in dentists and dental nurses working with amalgam. Uncharacteristic symptoms of chronic low-level Hg vapor exposure including weakness, fatigue, and anorexia have been observed in numerous studies of dental personnel. It is crucial to protect both human health and the environment against negative effects of Hg. In line with this, the use of dental amalgam in industrial countries is about to be phased out. In Norway and Sweden, the use of the filling material is banned.

Long term changes in health complaints after removal of amalgam restorations

OBJECTIVE

Concerns over adverse effects of mercury released from dental amalgam sometimes lead patients to request removal of their amalgam restorations. Several studies report improvement of subjective health after removal of amalgam restorations, but the mechanisms are unclear. The aim of this paper is to present data on long term changes in intensity of health complaints after amalgam removal in a group of patients with health complaints self-attributed to dental amalgam. Data from the five years follow-up in a clinical trial are presented and related to potential determinants of change.

MATERIALS AND METHODS

Patients previously referred to a specialty unit for health complaints attributed to amalgam restorations were included in the study. The 20 participants who were allocated to the treatment group had all amalgam restorations removed and replaced with other dental restorative materials. Intensity of health complaints was calculated from questionnaire data and personality variables were measured by MMPI-2.

RESULTS

At the follow-up five years after the amalgam removal was completed, intensity of general health complaints was significantly reduced (p=.001), but the symptom load was still high. The reduction was significantly correlated with concentration of mercury in urine at pre-treatment. There were no significant correlations with personality variables.

CONCLUSIONS

Removal of amalgam restorations was followed by a long term reduction of general health complaints, which was associated with mercury concentration in urine before amalgam removal. Additional studies are needed to confirm the potential mechanisms for the observed reduction.

Quantification of Hg excretion and distribution in biological samples of mercury-dental-amalgam users and its correlation with biological variables

This is the first study conducted to quantify the excretion and distribution of mercury (Hg) with time (days) in the biological samples collected from Hg dental amalgam users (MDA). The individuals, with Hg-based dental filling were selected, and their biological samples (red blood cells (RBCs), plasma, urine, hair, and nails) were collected on first, third, and 12th day of fillings. The concentrations of Hg observed in the biological samples of MDA were also correlated with the biological variables such as age, weight, restoration, fish consumption, number, and surface area of fillings. The concentrations of Hg in the biological samples of MDA were found 6-8 times higher than the non-amalgam users (control). The concentrations of Hg in the RBCs (4.39 μg/L), plasma (3.02 μg/L), and urine (22.5 μg/L) on first day of filling were found comparatively higher than the concentrations observed on third day (2.15, 1.46, and 12.3 μg/L for RBCs, plasma, urine, respectively) and 12th day (3.05, 2.5, 9.12 μg/L for RBCs, plasma, urine, respectively), while Hg concentrations were found lower in the hair and nails on third day of fillings (1.53 μg/g for hair and 2.35 μg/g for nails) as compared to the 12th day (2.95 μg/g for hair and 3.5 μg/g for nails). The correlations were found significant (p ˂ 0.05) between Hg concentrations in the biological samples of MDA and biological variables (the number of restoration, fish consumption, number, and surface area of fillings), while no significant (p ˃ 0.05) correlations were observed for Hg concentrations in the biological samples with age and weight of MDA. These observations unveil the fact that the use of Hg-based dental filling is the undesirable exposure to Hg which should be replaced by composite (a safer filling material).

Mercury health effects among the workers extracting gold from carpets and dusted clays through amalgamation and roasting processes

Mercury (Hg) is a highly toxic metal which can cause serious health effects. The aim of this research was to determine the concentrations of total Hg (T-Hg), methyl Hg (Me-Hg), and inorganic Hg (I-Hg) in the biological samples (plasma, red blood cells (RBCs), urine, hair, and nails) of the exposed goldsmith workers. This is the first study that determines the detailed Hg concentrations in the biological samples (plasma, RBCs, urine, hair, and nails) of the exposed goldsmith workers and correlates them with the diseases noted among the workers in a single paper. Biological samples were collected from goldsmith workers (n = 40) and analyzed for T-Hg, Me-Hg, and I-Hg using atomic absorption spectrometer equipped with mercury hydride system. The mean T-Hg concentration in RBCs (33 μg L(-1)), plasma (11.8 μg L(-1)), urine (167 μg L(-1)), hair (4.21 μg g(-1)), and nails (5.91 μg g(-1)) were higher than the control RBCs (1.64 μg L(-1)), plasma (0.55 μg L(-1)), urine (2.72 μg L(-1)), hair (0.35 μg g(-1)), and nails (0.51 μg g(-1)). All workers participated in this study were suffering from physical and mental diseases. The concentration of Hg was found higher among the workers suffering from mental diseases as compared to those suffering from physical diseases. Among the physical diseases, the most serious diseases were sexual dysfunction, skin diseases, and fatigue because the workers suffering from these diseases had higher concentration of Hg than the workers with other diseases. The occurrence of physical diseases (88%) was greater than the mental diseases (53%) among the workers. The correlations of physical and mental diseases with experience (years of work) and exposure time were significant (p < 0.05), while nonsignificant (p > 0.05) correlation was observed between demographic parameters and Hg concentrations in the biological samples of the workers. The burning process of amalgamated gold is a significant source of Hg exposure to goldsmith workers; therefore, awareness and precautionary measures are needed to provide protection to them.

Characterization of health complaints before and after removal of amalgam fillings--3-year follow-up

OBJECTIVE

Some patients attribute health complaints to amalgam fillings and report improvement of health after replacement of amalgam fillings. The aim of the present study was to characterize the changes of different health complaints after replacement of amalgam fillings and compare with an external reference group from the general population.

MATERIALS AND METHODS

The study group included 20 patients with health complaints attributed to amalgam fillings who were participants in the treatment group of a clinical trial at the Norwegian Dental Biomaterials Adverse Reaction Unit. The patients were asked to indicate the intensity of local and general health complaints on numeric rating scales (0-10) before removal of amalgam fillings and at follow-up 3 years after removal. Data from the patient group were compared with data from an external reference group (n = 441).

RESULTS

Before treatment the mean intensity of complaints were on a higher level in the treatment group compared to the reference group. The most frequently reported complaints in the treatment group were gastrointestinal symptoms, fatigue, pain from muscles and joints, symptoms from ear/nose/throat and difficulty concentrating. From pre-treatment examination to the 3-year follow-up 20 of 23 health complaints decreased, being statistically significant for taste disturbances, pain from muscles and joints, gastrointestinal complaints, complaints from ear/nose/throat and fatigue.

CONCLUSIONS

The inter-individual variation of intensities of health complaints was considerable and the reduction of health complaints varied for the different complaints. Several factors may be of importance for the observed reduction of complaint intensity.