Amalgam Mercury Research Articles

Toxic effects of mercury in dental amalgam

Toxic effects of mercury in dental amalgam

Dental Amalgam and the Minamata Convention on Mercury Treaty: Make Mercury History for All

Mercury, known as the most toxic non-radioactive element to man, poses a significant threat to all living beings and the environment in all its forms. As a global pollutant, it demands urgent attention and effective measures to mitigate its toxic effects. The Minamata Convention on Mercury Treaty, adopted in 2013 and enforced in 2017, stands as a vital instrument in combating this pervasive toxin. Presently, 144 countries have ratified the treaty, embodying the collective commitment to the mantra "Make Mercury History." As countries work diligently to eliminate mercury from various products and processes, such as thermometers, batteries, lighting, and cosmetics, dental amalgam remains a notable concern. Being one of the top mercury-containing products globally, dental amalgam has drawn attention for its phasedown approach within the treaty. The dental sector alone accounts for an estimated 340 tonnes of mercury usage each year. Alarmingly, mercury derived from dental amalgam infiltrates the black market, ultimately entering the artisanal small-scale gold mining (ASGM) sector, the primary source of global mercury pollution. Furthermore, dental amalgam plays a significant role in municipal wastewater mercury contamination, as it has been identified as the largest source of this toxic element in such environments. Considering its pervasive nature, diverse pathways of contamination, and its ability to bioaccumulate in both humans and the environment, it is evident that the toxic legacy of dental amalgam will persist long after the placement of the last amalgam filling. The pressing issue of mercury toxicity makes it imperative for action to be taken through the Minamata Convention on Mercury Treaty. As we strive to "Make Mercury History" for the well-being of all living organisms, mercury dental amalgam must be proactively addressed to prevent its continued contribution to global mercury pollution.

Pathway to mercury-free dentistry: an insight into past, present, and future.

The popularity of dental amalgam arises from its excellent long-term performance, ease of use, and low cost. However, there is a concern about the potential adverse health effects arising from exposure to mercury in amalgam. This review article critically discusses the safety of dental amalgam as a restorative material and our preparedness for a mercury-free road ahead. A database search was performed on PubMed and Google scholar using the keywords: "mercury-free dentistry", "mercury toxicity", "amalgam substitutes", "amalgam mercury toxicity". Inclusion and exclusion criteria were specified clearly. Relevant literature was also searched in the dental textbooks. Around 40 articles, highlighting mercury exposure among dental professionals and patients were included. Despite the overwhelming body of scientific evidence demonstrating amalgam to be a safe restorative material, concerns about the toxic effects of mercury persist. The real challenge is to find a suitable amalgam substitute and to follow the mercury hygiene measures closely.

Genotoxic effects of dental amalgam based on micronucleus assay in epithelial cells from the oral cavity in patients

The most often utilized restorative material is dental amalgam. It has existed for more than 150 years. Dental amalgam is an amalgam of silver and mercury. Silver, tin, copper, and occasionally zinc are the main ingredients of the fine powder that constitutes the silver alloy. Dental amalgam is produced as a consequence of a chemical process involving silver alloy and mercury. When alloy and mercury interact, an amalgamation reaction takes place. The mercury in amalgam is chemically bonded to the other metals, making it stable and safe for use in dental applications even though some types of mercury are hazardous. In the current investigation, 50 samples were taken from participants who had dental fillings, and 50 samples were taken from those who did not. According to the study's findings, there are a total of 25.6 ± 3.40 mean micronuclei in the control group and 78.8 ± 7.08 mean micronuclei in the sick group. These results suggest that epithelial cell genetic damage may be estimated using the micronucleus test.

The effect of magnetic resonance imaging on mercury release from dental amalgam at 3T and 7T

ObjectivesTo measure mercury release from standardised hydroxyapatite/amalgam constructs during MRI scanning and investigate the impact of static field strength and radiofrequency (RF) power on mercury release. MethodsAmalgam was placed into 140 hydroxyapatite disks and matured for 14-days in artificial saliva. The solution was replaced, and samples split into five groups of 28 immediately prior to MRI. One group had no exposure, and the remainder were exposed to either a 3T or 7T MRI scanner, each at high and low RF power. Mercury concentration was measured by inductively coupled plasma mass spectrometry. Groups were compared using one-way ANOVA, and two-way ANOVA for main effects/ interaction of field strength/ RF power. ResultsMercury concentration was increased in the 7T groups (high/ low: 15.43/ 11.33 ng mL−1) and 3T high group (3.59) compared to control (2.44). MRI field strength significantly increased mercury release (p < .001) as did RF power (p = .030). At 3T, mercury release was 20.3 times lower than during maturation of dental amalgam, and for the average person an estimated 1.50 ng kg−1 of mercury might be released during one 3T investigation; this is substantially lower than the tolerable weekly intake of 4,000 ng kg−1. ConclusionMercury release from amalgam shows a measurable increase following MRI, and the magnitude changes with magnetic field strength and RF power. The amount of mercury released is small compared to release during amalgam maturation. Amalgam mercury release during MRI is unlikely to be clinically meaningful and highly likely to remain below safe levels.

Alarming Findings on Mercury Dental Amalgam – Latest Research Using the National Health and Nutrition Examination Survey (NHANES) Database: A Mini-Review

Mercury dental amalgam has been used as a dental restorative material for almost 200 years. Even though mercury is the most toxic non-radioactive material known to man, there has been an ongoing controversy about its safety since it was first introduced for use in dentistry. In 2013, a global treaty was adopted to address the dangers of mercury-containing products and processes called the Minamata Convention on Mercury Treaty, which went into force in 2017. This global mercury treaty listed mercury dental amalgam as a “phase-down” product. It is the only product in the treaty that is implanted in the human body and the only product listed simply as “phase-down”. While many evidence-based scientific papers have reported that mercury dental amalgam negatively affects human health, it is still the most commonly used dental restorative material in the world. Since the treaty has gone into force, many developed countries, countries with emerging economies, and developing countries have banned the use of mercury dental amalgam in the spirit of the treaty whose mantra is “Make Mercury History”. However, a date certain to ban mercury dental amalgam’s use globally has not yet been achieved. The latest significant findings on human exposure to mercury dental amalgam using the “Gold Standard” National Health and Nutrition Examination Survey (NHANES) database, may finally be the catalyst that will achieve the goal and “Make Mercury History” in the dental sector.

The Determination of Algae Group as Bioindicator of Water Quality Change Affected by Mercury Release from Artisanal Small-Scale Gold Mining (ASGM)

Artisanal small scale gold mining (ASGM) practices typically use mercury for amalgamation. Near water environments this can degrade water quality and aquatic biota, including algae. Changes in algal communities can reflect water environment disturbance. The aim of this study was to determine if algae can be used as bioindicator of river water quality impacted by ASGM activities. The research was conducted from July to October 2018 at thirty sampling sites along rivers near ASGM areas in several regencies of Indonesia. Composite samples of water and sediment were collected. A plankton net and brushing methods were used to collect planktonic and benthic algae, respectively. The physicochemical parameters of the water and the sediment as well as the dominant algae genera were analyzed statistically with principal component analysis. The results showed that the total mercury concentration in the water ranged from &lt;0.04 to 20 µg.L-1, while in the sediment the maximum value was 13,500 µg.kg-1. The total mercury content in the sediment was negatively correlated with the dominant benthic Navicula at a significance level of p &lt; 0.05. This means that a low density of benthic Navicula can be proposed as a bioindicator of water quality, indicating the increase of mercury pollution in sediment.

Detection of Mercury Vapor in Selected Governmental Dental Health Care Centers in Al-Karkh- Baghdad

Almost all governmental centers in Iraq are still using mercury amalgam in spite of available alternatives; that make the initial assessment very important to assess the current situation. The survey included visiting (17) site within health centers in three locations in each (the room space, amalgam capsule containers and medical waste storage containers). (510) measurements (10 readings in each location) have been taken for every health care center in Al-Karkh side in Baghdad (10 general health centers, 7 specialists' center). Potential quantity of emitted mercury vapor has been measured using a portable mercury vapor detection device (TRACKER 3000 IP). Broad variability was noted in the concentration of Hg vapor emitted depending on the amount of empty capsules that were collected, opened or closed container, room area, number of chairs in the room and patients per day, number of full containers and applying environmental and health safety rules. 94.1 % of visited centers exceeded the lowest allowed occupational levels, 76.5 % recorded high concentrations exceeding Ceiling Limit Value while 94.1 % exceeded the Minimum Risk Level. The mercury vapour concentration in work space and the mercury vapour intake by inhalation of chronic daily exposure have linear relation. Mercury dental amalgam and its empty capsules in healthcare centers are a major source of emitting toxic mercury vapor causing chronic and acute exposure to population and for most dentists. Keywords: Mercury vapours; Occupational exposure limits; Dental Mercury Amalgam

Biocompatibility of Amalgam vs Composite - A Review.

The Minamata Convention resulted in restrictions in the use of amalgam in daily dental practice. This opens up new discussions about the biocompatibility of amalgam, but also of composites as alternative materials. In the following review article, these issues will be discussed in more detail to provide dentists with a knowledge base for themselves and for communication with their patients. In addition to mercury in amalgam or monomers in composites, bisphenol A and nanoparticles generated during the grinding, polishing or removal of restorations must also be included in the biocompatibility evaluation. In laboratory tests, these substances cause toxic reactions, and bisphenol A also exhibits estrogen-like effects. However, it must be taken into account that the concentrations used in laboratory tests are much higher than in clinical practice. Thus, both amalgam and composite can be used in the general population. Nevertheless, for scientifically, politically and legally defined risk groups (e.g. dental personnel, allergic persons, pregnant or lactating women, children under 15 years of age, people with certain systemic diseases), indication restrictions and precautionary measures must be observed. The well-known amalgam discussion has taught us the importance of thorough and open risk communication with the patient.

Symmetrization and Amplification of Germicidal Radiation Flux Produced by a Mercury Amalgam UV Lamp in Cylindrical Cavity with Diffusely Reflective Walls

The study focused on increasing the efficiency of germicidal UV radiation by using highly diffuse reflective materials such as PTFE in irradiated cavities of UV air purifiers. In a conventional cylindrically symmetric cavity with a linear amalgam mercury lamp as UV-radiation source on the axis UV-radiation, flux directed from the lamp to the walls dropped from the axis to the periphery. To increase the UV irradiation, the walls are often made mirror-reflective, but the radiation flux distribution remained radially symmetric with a maximum on the source emitting surface in this case as well. When most of the emitted light is returned to the source after one reflection, the conditions of its operation are disturbed. If the walls are made of highly diffuse reflective materials, the radiation flux density inside the cavity increases on average, and its distribution becomes uniform and highly symmetric. Thus, the effect of amplification of the radiation flux due to the highly diffuse reflectivity of the walls increases with radius and reaches a maximum at the wall. Experiments were performed to demonstrate increasing amplification of germicidal UV radiation flux with a diffuse reflection coefficient in cylindrical cavities with walls of PTFE and ePTFE. The irradiation of the cavity wall was observed to increase up to 20 times at the resonant mercury line of 253.7 nm and up to 40 times at some non-resonant lines of the visible range due to highly diffuse reflectivity of the cavity walls. The flux amplification effect was limited by the diffuse reflectivity value of the walls and absorption coefficient of the radiation emitting surface. A formula for calculating the radiation flux amplification factor in a diffusely reflecting cylindrically symmetric cavity was derived for the case of Lambertian source and reflector, including wall reflectivity and source surface absorption coefficients. The effects of heating and cooling of the mercury lamp amalgam directly affected the amplification, and symmetrization of germicidal irradiation was observed and is discussed in the paper. Numerical calculations were performed by the ray tracing method. The calculated model was verified by comparing the numerical results with those of both the approximate theoretical consideration and experiments. The promising use of diffusely reflecting cylindrical cavities for UV air purifiers is discussed. Designs of air inlet and outlet ports that allow effective locking of germicidal radiation inside the UV air purifiers were considered. The results of this work may be of interest for further developments in the UV disinfection technique.

Fabrication and characterization of micro alumina zirconia particulate filled dental restorative composite materials

AbstractComposite resin is quickly becoming the most extensively utilized material in the field of cosmetic and restorative dentistry. It eliminates the problem of poisonous nature caused by the amalgam's mercury content. This research article is based on the outcome of adding micro‐alumina and zirconia particulates filled dental composites on the physical properties, mechanical properties, and wear analysis. Three dental composites named AZDC2, AZDC4, and AZDC6, were prepared. Alumina microparticles were constant (6 wt%) while zirconia microparticles were varying (2, 4, and 6 wt%). Two‐body wear was performed on pin‐on‐disc friction &amp; wear test rig under dry sliding for all three dental composites under different normal load (20, 40, and 60 N) and sliding speed (10, 15, and 20 mm/s). The experiments were designed as per L9 Taguchi orthogonal array. The least volumetric wear was found in AZDC6 dental composite under a sliding velocity of 15 mm/s and a normal load of 20 N. From the ANOVA analysis, normal load and filler content were the significant factors affecting the volumetric wear with a significance level 5%, respectively. Dental composite AZDC6 exhibited maximum compressive strength (451.49 MPa). Micro hybrid particulates‐filled dental composites improve physical and mechanical characterization.

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.

Oral lichenoid reaction to dental amalgam and its association with desquamative gingivitis “a diagnostic conundrum”: A case report

Oral lichenoid lesions (OLLs) are chronic inflammatory lesions of the oral cavity, and they can hardly be distinguished from oral lichen planus (OLP). Various terms have been used in the literature, including lichenoid contact lesions, lichenoid contact stomatitis, and oral lichenoid reactions. The concept of contact allergy to dental restorative materials in OLLs has been widely recognized but somewhat controversial. The most common causative allergen is mercury in dental amalgam, with a few reported cases from other materials. These lesions are most often seen in direct topographic relation to the causative agent. The possible correlation between the presence of desquamative gingivitis (DG) associated with autoimmune diseases and the worsening of periodontal parameters has been discussed in the literature, since both conditions can share immuno-inflammatory mechanisms in their pathogenesis. The DG may indirectly worsen the accumulation of plaque in the affected sites, since pain and bleeding may inhibit the patient’s oral hygiene. The aim of this report is to present a clinical case of OLLs associated with amalgam restoration and its association with DG for a three-month follow-up period.

Mercury in Dental Amalgam, Online Retail, and the Minamata Convention on Mercury.

The Minamata Convention on Mercury (ref. 1) is a global treaty to protect human and environmental health from adverse effects of the toxic element mercury and its compounds. During the Third Conference of Parties (COP-3) in November 2019, elimination of the use of dental amalgam in oral health care was discussed. Dental amalgam is one of the most commonly used restorative materials in oral health care due to its strength and longevity (ref. 2). However, the use of mercury in an amalgam adds to global environmental mercury pollution and can contribute to adverse health effects on humans and other organisms. The outcomes of the COP-3 meeting included a call for information on the availability at a national scale, the economic and technical feasibility of alternatives, and the associated risks or benefits. In this feature, we discuss the risks and benefits of dental amalgam, the global tracking of availability and procurement, and the implications and realities for global phase out. We suggest a better accounting of mercury use in dental amalgam is needed with sales being made only to registered practitioners via a Know Your Customer approach.

Exposure to mercury from dental amalgam: actual contribution for risk assessment.

Mercury dental amalgam restorations are an important source of chronic exposure to mercury in the whole population and special attention should be paid not only to occupational exposure to mercury during the preparation and administration of amalgam. The authors' report is an up-to-date contribution to the health risk assessment of mercury use in dentistry, namely occupational exposure to mercury in dentists working with dental amalgam and exposure to mercury in persons treated with amalgam dental restorations. Determination of total mercury in samples of biological material (urine, hair) was performed during 2017 and 2018 in 50 persons by the AAS method using the mercury vapour generation technique at 254.6 nm. Current dental exposures based on the most recent findings do not exceed acceptable risk levels and are below the biological limit of mercury in urine valid for occupationally exposed persons (100 μg.g-1 of creatinine), namely median value was 1.48 (min. < limit of detection (LOD), max. 17.14) μg.g-1 of creatinine (40 persons), total mercury content in hair of dental personnel expressed as median value was 0.340 (min. 0.060, max.1.628) μg.g-1. In controls (10 persons) was total mercury content in urine expressed as median value 0.36 (min. < LOD, max. 2.74) μg.g-1 of creatinine, in hair was median value 0.224 (min. 0.059, max. 0.453) μg.g-1. Authors support opinion that amalgam fillings in the oral cavity are a permanent source of mercury for the body itself.

Exposition au mercure et état de santé des médecins dentistes de deux régions du centre du Maroc: enquête transversale descriptive

Introductionl´exposition au mercure est un problème de santé publique mondialement reconnu. Si les intoxications aiguës ou subaiguës par ce métal font l´objet d´un consensus diagnostique, l´impact d´une exposition chronique à de faibles doses est encore sujet à débat. En dentisterie, le mercure est utilisé pour la réalisation des amalgames dentaires. De ce fait, les professionnels de la médecine dentaire et spécialement des médecins dentistes représentent une population exposée à ce facteur de risque. Dans ce contexte, une enquête épidémiologique descriptive, transversale et exhaustive a été réalisée afin d´évaluer cette exposition chez les médecins dentistes dans deux régions du centre du Maroc. Parallèlement, leur état de santé globale a été relevé afin de juger de la pertinence d´une enquête étiologique ultérieure pour étudier l´impact probable de l´exposition à ce facteur de risque.Méthodesla présente étude a été réalisée par le biais d´un questionnaire auto-renseigné par les participants. L´exposition professionnelle des médecins dentistes a été évaluée en déterminant la fréquence d´utilisation de l´amalgame dentaire. Les différentes sources de mercure qui modulent la pollution de fond ou qui provoquent des pics d´exposition et qui sont en rapport avec l´environnement ou les habitudes du travail ont aussi été étudiés. Les sources d´exposition non professionnelle prises en compte sont le tabagisme, la vaccination, la consommation de poisson et la présence des amalgames dentaire en bouche. Enfin, l´état de santé des praticiens recrutés dans l´étude a été sondé globalement en se basant sur leurs déclarations.Résultatscent quatre-vingt douze (192) médecins dentistes ont été recrutés dans cette étude. Parmi lesquels, 76,04% déclarent utiliser l´amalgame dans leur pratique avec une fréquence variable. De plus, plusieurs sources de surexposition en rapport avec les conditions ou les habitudes du travail ont été mises en évidence. La principale source d´exposition non professionnelle dans notre population est en rapport avec la présence des amalgames dentaires en bouche (63,45%). Les plaintes sanitaires exprimées par les participants concernaient en chef de file les problèmes neuropsychologiques et ce chez 46,35% de la population. En prenant en compte la neurotoxicité reconnue du mercure, une étude étiologique s´avère parfaitement justifiable dans notre contexte.Conclusionl´exposition au mercure chez les médecins dentistes des régions étudiées est réelle. Des mesures de prévention sont à promouvoir. La réalisation d´une recherche étiologique pour juger l´impact de cette exposition est parfaitement indiquée.

Mercury Contamination from Dental Amalgam.

Mercury in dental amalgam is a hidden source of global mercury pollution, resulting from the illegal diversion of dental mercury into the artisanal and small-scale gold mining sector, to crematoria emissions from the deceased and sewage sludge that is sold to farmers. These significant mercury sources result in air, water, and food contamination that consequently have a negative impact on human health. The aim of the present study was to investigate and report on all of the various pathways mercury in dental amalgam can enter the environment. The present study searched the electronic data bases of PubMed and Google Scholar. Peer reviewed journals and references of studies included for full-text review were examined for potentially relevant studies. Articles published between 2000 to 2018 were searched and specifically screened for articles that referenced "Dental Amalgam," and the following key words in various combinations: "Minamata Convention on Mercury Treaty," "Sewage Sludge," "Cremation," and "Artisanal and Small-Scale Gold Mining." Data were included on the most populous countries of China, India, the United States, Brazil, and the European Union collectively. We also included data on cremation statistics and current global trends, looking at populations where cremation is a common practice, such as Japan and India. Dental amalgam represents a significant, but understudied area of global mercury pollution that includes cremation, sewage sludge, burial, and small-scale gold mining. Mercury used in products and processes, including dental amalgams, is a global pollutant. Even after the last mercury dental amalgam is placed, its toxic legacy will continue for decades, because of its pervasive bioaccumulation in the environment. Government regulatory agencies should make it mandatory to utilize available technologies, not only in developing countries, but also in developed countries, to reduce mercury contamination. The authors declare no competing financial interests.

Lessons from mercury dental amalgam phase down for developing economies

This paper highlighted six pertinent issues that developing economies should focus on with regards to mercury dental amalgam phase down. The need to set up structures for monitoring and evaluation of materials and technologies used in clinics, laboratories and hospitals was discussed as well as the need to provide research data on mercury pollution that may be peculiar to developing economies. The urgent needs to update dental schools' curricula and update the training of general Dental practitioners were also discussed. Aframework for curriculum development, review and update was proposed using the Minimum Intervention Treatment Plan (MITP). Two other caries management pathways-the International Caries Classification and Management System Caries Management Pathway (ICCMS-CaMP) and the Caries Management by Risk Assessment (CAMBRA-CaMP) were also highlighted. A “frog-leaping' phase down approach was proposed that took cognizance of the poor infrastructure for waste management in developing economies. Opportunities for new oral health policy initiatives with regards to integration of oral health into national and international health agenda were also discussed. Keywords:Mercury, dental amalgam, phase down, lessons, curriculum update.

Occupational Exposure to Mercury in Dental Professionals Performing Mercury Dental Amalgam Restoration Removal Procedures: A Computational Fluid Dynamics Air Quality Risk Assessment Model Supported by In-Vitro Results

Aim: To quantify risks associated with exposure to dental amalgam mercury resulting from aerosolization during and following dental fillings removal procedures performed by dental professional over a lifetime of professional practice. Methods: A computational fluid dynamics model was generated using particle size, density, and compositional data obtained from in-vitro aerosolization experiments simulating the environment and breathing conditions of a dental professional performing a dental amalgam restoration removal procedure. Analysis was carried out using scanning electron microscopy and inductively coupled plasma – optical emission spectrometry. Data was collected in 2018-2019. Results: Experiments reveal that approximately 58% of mercury contained within the amalgam material is vaporized during removal procedures, and that aerosolized particles, ranging in size from 0.85 to 570 microns, may remain in suspension for nearly two minutes in the area surrounding the working surface. For dental professionals performing on average 9 such restorations per week, the estimated chronic daily intake (CDI) of mercury is 49 micrograms/kilogram-day, which exceed – by more than 20 times – the CDI recommended by the World Health Organization. Data analysis was performed in 2019. Conclusion: Because the CDI exceed recommended safe exposure limits, dental professionals should wear respiratory and personal protective equipment to protect them from exposure to both mercury vapour and mercury-containing particulates for at least two minutes following removal procedures.

Estimation of Mercury Emission from Incineration of Extracted Teeth with Dental Amalgam Fillings in South Korea.

This study is aimed to estimate the levels of mercury emission related to amalgam fillings at dental institutions in order to provide basic data for establishing a management protocol for extracted mercury-containing amalgam fillings. We conducted a cross-sectional study at a dental clinic of a general hospital (City of Daegu), a dental hospital (City of Daegu), and five private dental clinics (one in the South and four in the North Gyeongsang Province). The extracted anterior and posterior teeth (N = 1208) were separated, and the amalgam filling rate of the posterior teeth was assessed. After cutting out the amalgam from filled posterior teeth, the weight of the amalgam was measured, and the estimated mercury emission was calculated based on the equation, where annual number of extracted posterior teeth × amalgam filling rate (%) × mean amalgam weight (g) × 0.5 (the proportion of mercury in amalgam). We found that 48.86 kg (95% confidence interval [CI] 41.53–58.63 kg) of mercury had been incinerated along with the extracted teeth. After applying the dental institution weights, the estimated amount of mercury was 42.53 kg (95% CI 34.11–52.17 kg). The amount of mercury incinerated with extracted posterior teeth at Korean dental institutions is therefore about 42.53–48.86 kg/year.