Effects of Removal Conditions on Mercury Amount Remaining in the Oral Cavity and inside Drainage System after Removing Dental Amalgams

Mercury is produced and drained into the environment by removing dental amalgams, which may cause mercury pollution. This study aimed to clarify the mercury amount remaining in the oral cavity and inside the drain system after removal. The effects of the removal conditions and differences in drainage systems were also investigated. Dental amalgams filled in the tooth and placed in a phantom head were removed using an air turbine under several conditions (two removal methods, absence of cooling water, and intraoral suction). Then, the oral cavity was rinsed with 100 mL of water (oral rinse water), and 500 mL of water was suctioned to wash the inside of the drainage system (system rinse water). Both water samples were collected in two ways (amalgam separator and gas-liquid separator), and their mercury amounts were measured. It was found that the amount of mercury left in the oral cavity and drainage system after dental amalgams removal could be reduced when the amalgams were removed by being cut into fragments as well as using cooling water and intraoral suction. In addition, using amalgam separators can significantly reduce the amount of mercury in the discharge water and prevent the draining of mercury into the environment.

The Hazardous Effects of Dental Amalgam Fillings in Human Body: A Systematic Review

The Dental amalgam used in the dental fillings is basically an alloy of mercury (Hg). The amalgam is one of the most commonly used and versatile restorative material. Since more than 150 years this alloy of mercury, that is amalgam is used for it been economical, easy to use, durable, high strength and bacterio-static characteristics. Due to environmental pollution, detrimental health its use is decreasing in recent times. Also its not so appealing like the other materials used that resemble the tooth color. The tooth coloured restorative materials are recommended by both the doctor and the patient. Many researchers suggested that over the period of time the mercury from the filling might leach into the mouth. Thus in this study a detailed review of all the literature available online is done to understand the hazardous effects of dental amalgam fillings in the human body. The systematic literature search using Scopus, PubMed, EMBASE and Web of Science electronic databases was done using PRISMA. The experiments conducted in Sheep and monkey suggested the penetration of amalgam into the jaw bone of the patient with dental restorations. Constant exposure of mercury at lower levels can also lead to multiple sclerosis, rheumatoid arthritis and systemic lupus erythematosus. Most commonly reported renal dysfunction due to the dental amalgams are Tubular and Glomerular damage of the kidneys.

Should dental amalgams be used in dental training? The perspectives of dental academics at a university in South Africa

Dental amalgam has been used in dentistry for the last 150 years to restore posterior teeth. Concerns regarding the safety issues with amalgam due to its mercury content have lead to the introduction of composite dental material to restore posterior teeth. This has transformed the teaching and training trends of direct restorative materials for posterior teeth. This descriptive study aimed to gain insight into academic staff and clinical supervisors’ perceptions regarding the use of dental amalgams in the teaching of restorative dentistry. This study used a qualitative method of data collection. Two focus group discussions were conducted between March and May 2020. Seventeen participants were invited to participate. Fourteen responded and participated, yielding an 82% response rate. The data identified two major themes, viz. the challenges experienced with the teaching of dental amalgam and curriculum development recommendations. Clinical quota requirements, disposal of waste products, and occupational and environmental risks regarding mercury exposure were sub-themes. Some of the curriculum recommendations included the skills gained during cavity preparations, the training and quota requirements of dental materials, and teaching trends locally, nationally and internationally.This study revealed that dental amalgam is still an integral part of the restorative dentistry curriculum at the university. However, the teaching of resin composite now occupies more than fifty percent of the restorative dentistry curriculum. Academics and clinical supervisors show a greater affinity for the placement of composite restorations.

An Overview of Evidence that Mercury from Dental Fillings may be an Etiological Factor in Many Health Disorders

Aim: The purpose of this paper is to summarize the research regarding the toxic health effects caused by mercury dental amalgams. Method: The study involved summarizing scientific articles in journals regarding health effects of dental amalgam mercury. Results: The science strongly suggests dental amalgam mercury may be an etiological factor in numerous health disorders. Mental health seems to be affected the most including such conditions as depression, anger, and irritability. Studies have also associated it with schizophrenia and bipolar disorders. The cardiovascular system also is affected including high blood pressure, heart rate, hemoglobin, hematocrit, and red blood cells. Subjects with amalgams have a decreased T lymphocyte percentage compared to a control, and the immunoglobins IgG, IgA, and IgE correlated with the number of amalgams. Myopia is reduced in amalgam bearing subjects but amalgam mercury is constricting the visual field. When comparing total health disorders of subjects with amalgams compared to those without, they suffered 45% more health disorders. Urine and hair mercury levels were significantly higher in subjects with amalgams compared to those without. The scientific evidence strongly suggests that amalgam mercury is associated with Alzheimer’s disease, multiple sclerosis, and amytrophic lateral sclerosis. Research has shown when amalgams are removed many health conditions improve. Conclusion: The evidence is overwhelming that mercury from dental amalgam is an etiological factor in many health disorders.

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).

Dental amalgam risks in dental staff: systematic review

Mercury is an essential constituent of dental amalgams, several studies have shown that dental personnel who work with dental amalgams are chronically exposed to mercury vapors. The World Health Organization considers that inhaling mercury vapors can have harmful effects on the nervous, immune, pulmonary and renal systems. The objective of this review was to collect and analyze data relating to the exposure of dental personnel to mercury and the possible harmful effects on human health. All biomonitoring studies published between 2002 and 2019 measuring mercury in hair, blood, urine and nails were included. Dentists reported higher levels of mercury in their biomarkers compared to control groups. These levels reflected occupational exposures to chronic low levels of elemental mercury in dental amalgam fillings. Some studies have shown a high prevalence of neurological symptoms and memory deficit in dental staff compared to controls. Studies based on genes involved in mercury metabolism have shown associations between sources of mercury exposure and single nucleotide polymorphisms in these genes. It is important that preventive measures are strengthened to reduce exposure to mercury and that a biomonitoring program for dental professionals exposed to mercury vapors is implemented.

Modeling Subjective Symptoms Related to Micro-Hydrargyrism in a Population of Moroccan Dentists

BACKGROUND፡ The ability of mercury to deposit throughout the body and alter a wide range of molecular and cellular pathways results in a polymorphic and complex clinical phenotype with over 250 possible symptoms. However, some of them are recurrently cited as evoking chronic mercury poisoning. In this light, dentists users of dental amalgams are chronically exposed to mercury so that in-depth epidemiological investigations and adapted statistical methods are required to highlight adverse effects of this exposure.METHODS: In order to study the health impact of the occupational mercury exposure in a population of liberal dentists practicing in two Moroccan regions, a list of eighteen subjective symptoms commonly associated with micro-hydrargyrism was drawn up. Then, seven statisctical models adapted to count data were fitted. Finally, three methods were used to compare their relative performance in order to choose the most appropriate one.RESULTS: The adopted logical path, from the response variable selection till models’ comparison, led us to lean towards quasi- Poisson regression as the best way to predict the number of symptoms declared by dentists according to mercury exposure.CONCLUSIONS: Interpretation of the selected model allowed us to conclude that the reduction of dental amalgam use allows the reduction of subjective symptoms related to mercury exposure.

Mercury Exposure Assessment in Mother–Infant Pairs from Continental and Coastal Croatia

The main source of mercury (Hg) exposure in the general population is fish. Another possible source is dental amalgam. Here, we compare the levels of Hg and selenium (Se) in samples of maternal and fetal origin collected shortly after childbirth of healthy postpartum women in the coastal (n = 96) and continental (n = 185) areas of Croatia related to maternal seafood/fish consumption. We also evaluated Hg concentrations and maternal serum metallothionein (MT2) concentrations in relation to the number of dental amalgam fillings, and MT2A-5A/G (rs28366003) polymorphism. The levels of Hg and Se in maternal hair and blood/serum, placenta and cord blood/serum increased in relation to increasing fish consumption with the highest values in subjects from the coast. The concentrations of each element and between elements correlated across the matrices. Increasing amalgam number correlated linearly with increased Hg levels in maternal and cord serum and was not associated with serum MT2. No association of MT2A-5A/G polymorphism and Hg or Se levels were found. The results confirmed higher fish consumption in coastal vs. continental Croatia and increases of both Hg and Se related to fish consumption in all analyzed samples. Increased blood Hg reflected the predominant MeHg share from seafood, while increased serum Hg matched exposure from dental amalgams.