[Reconsidering mercury pollution of the environment from dental amalgam in and outside dental offices and its prevention].
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Air Pollutants, Occupational↗
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Results for “DENTAL AMALGAM”
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[Risk behavior associated with the manipulation of dental amalgam in Senegal].
Dental amalgam is a combination of mercury, silver, tin and copper used in the treatment of the dental decays. Amalgam is used in dentistry since many years. Actually a large discussion held according to environmental pollution and risk of intoxication for the patient and the dentist himself. The aim of our survey concerning 103 dentists was to determine the quantity of mercury used in a year, to see the risks linked with the equipment and the manipulation of amalgam and to study the incoming of the trashes of amalgam. Our results showed that among the dentists: 44.66% used 250 to 500 g of mercury by year, 14.56% used their hands for insertion of amalgam in the cavities, 10.68% used their hands for condensation of amalgam in the cavities, 87.38% throw their amalgam on the trash.
Dental Amalgam↗
Mercury in dental amalgam--a public health concern?
Dental amalgam has been the subject of intermittent controversy since it was introduced into dental practice approximately 150 years ago. The controversy has centered on the use of mercury in dental amalgam and the potential health implications to dental patients and dental health professionals from mercury exposure. In recent years the debate over the use of dental amalgam has intensified due to several articles in professional journals and media coverage by television and the press. This paper reviews the recent literature regarding dental amalgam, describes the activities of the antiamalgamists, examines the alternatives to dental amalgam, and reviews the recommendations for additional research. The existing scientific evidence does not demonstrate that mercury in dental amalgam poses a public health hazard. However, researchers on both sides of the controversy agree that much remains to be examined about the health implications of dental amalgam and that the subject merits continued research.
American Dental Association↗
A consideration of amalgam. The renaissance in dental amalgam. 3.
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Dental Amalgam↗
Comprehensive medical examination of a group of patients with alleged adverse effects from dental amalgams.
Mercury from dental amalgams does not seem to cause dose-related intoxications. However, animal studies have shown that high-dose exposure to mercury may support various types of immunologic reactions. Ten patients claiming that their symptoms were caused and aggravated by amalgam therapy were selected for a study of the effects of removal of one amalgam restoration followed by placing of a composite filling. Clinical symptoms and the result of laboratory tests were recorded. Six patients had contact allergies to metals, three of them to mercury ammonium chloride. The comparison of pre- and post-experimental test results showed significant reductions in p-IgE and dU-albumin and significant increases in p-C3d and dU-beta 2-microglobulin. There was no laboratory evidence of a direct toxic effect by mercury on the patients. The observed response by some of the studied factors to the low acute exposure to amalgam may imply that an activation of the immune system occurred.
Adult↗
Adverse immunological effects and autoimmunity induced by dental amalgam and alloy in mice.
Dental amalgam fillings are the most important source of mercury exposure in the general population, but their potential to cause systemic health consequences is disputed. In this study, inbred mice genetically susceptible to mercury-induced immune aberrations were used to examine whether dental amalgam may interfere with the immune system and cause autoimmunity. Female SJL/N mice were implanted in the peritoneal cavity with 8-100 mg silver amalgam or silver alloy for 10 weeks or 6 months. Chronic hyperimmunoglobulinemia, serum IgG autoantibodies targeting the nucleolar protein fibrillarin, and systemic immune-complex deposits developed in a time- and dose-dependent manner after implantation of amalgam or alloy. Splenocytes from mice implanted with amalgam or alloy showed an increased expression of class II molecules. The functional capacity of splenic T and B cells was affected in a dose-dependent way: 10 weeks of low-dose and 6 months of high-dose amalgam implantation strongly increased mitogen-induced T and B cell proliferation, whereas 10 weeks of high-dose implantation decreased the proliferation. Not only mercury but also silver accumulated in the spleen and kidneys after amalgam implantation. In conclusion, dental amalgam implantation in a physiological body milieu causes chronic stimulation of the immune system with induction of systemic autoimmunity in genetically sensitive mice. Implantation of silver alloy not containing mercury also induced autoimmunity, suggesting that other elements, especially silver, have the potential to induce autoimmunity in genetically susceptible vertebrates. Accumulation of heavy metals, from dental amalgam and other sources, may lower the threshold of an individual metal to elicit immunological aberrations. We hypothesize that under appropriate conditions of genetic susceptibility and adequate body burden, heavy metal exposure from dental amalgam may contribute to immunological aberrations, which could lead to overt autoimmunity.
Animals↗
Antibacterial properties of and element release from some dental amalgams.
Nine commercial dental amalgams were tested for antibacterial properties in vitro. A bactericidal test on salivary bacteria, a growth inhibition test on Streptococcus mutans OMZ 176, and a time-dependent bactericidal test on Strep. mutans were used. All amalgams displayed some antibacterial properties. Dispersalloy and Revalloy were strongly antibacterial in all tests; ANA 2000 and Sybraloy killed Strep. mutans but were less potent in the salivary test and in the growth inhibition experiments. The copper amalgams, Neo-Silbrin and Cupromuc, were the most active in the salivary test but less inhibitory in the growth curve experiments. Spheraloy, Indiloy, and Amalcap showed intermediate activity in the salivary bactericidal test but were relatively weak in the growth inhibition studies. Analysis of Hg, Ag, and Cu in media from the growth inhibition studies showed release of Hg from the copper amalgams and, particularly, from Revalloy; Indiloy gave off Ag, whereas Neo-Silbrin, Cupromuc, Sybraloy, and ANA 2000 released more Cu than the other brands.
Bacteria↗
Acceleration of corrosion of dental amalgam by abrasion.
Dental amalgam shows passive behavior, but the protective film can be destroyed by abrasion. In this study, specimens of both low- and high-copper amalgam were abraded, and the effect on the corrosion behavior was examined. The electrochemical measurements showed that the corrosion rate was substantially increased, and that re-passivation was relatively slow.
Copper↗
The future of dental amalgam: a review of the literature. Part 2: Mercury exposure in dental practice.
This is the second article in a series of seven on the future of dental amalgam. It describes the means of exposure to mercury which can occur in dental surgeries from the storage of mercury, preparation and placement of dental amalgam restorations, polishing dental amalgam restorations, the removal of amalgam fillings and the storage of waste amalgam. It also reports on the monitoring of dental practices and studies on the mercury air levels in dental surgeries and blood and urine levels in dentists and their staff. Also, studies which compare these levels with the health and neurobehaviour of dentists and their staff are included. In addition, it discusses post-mortem studies of the mercury levels in body organs in dentists and controls. It then recommends methods for the safe handling of mercury and dental amalgam. Finally, it discusses the issues surrounding the release of mercury into the environment from dental practices and industry.
Air Pollution, Indoor↗
Effect of admixed indium on properties of a dispersed-phase high-copper dental amalgam.
A new dental amalgam alloy containing admixed indium is available for clinical use. The purpose of this study was to conduct a full range of laboratory tests on two alloys containing differing amounts of admixed indium and on a similar alloy that did not contain indium. Results showed that less mercury was required to mix the alloys containing indium since admixed indium promotes wetting of the alloy. Back-scattered electron images showed the Ag-Hg matrix to be in good apposition to the Ag-Sn particles and to the Ag-Cu eutectic spheres, and there was no evidence of unreacted indium. The alloys containing admixed indium demonstrated improved resistance to creep and very little dimensional change upon setting. The early compressive strength was low for the alloys containing indium, but compressive strengths were significantly higher than those of the alloy without indium at 24 h and 7 d. Some improvement in resistance to marginal leakage and to corrosion was shown for the alloys containing indium.
American Dental Association↗
A new instrument for mercury vapor evacuation during clinical work with dental amalgam.
Clinical work with dental amalgam, cutting as well as filling and polishing operations, results in an increased level of mercury vapor in the breathing zone of the patient and often also in that of the dentist. The mercury levels can be minimized by the use of a high volume evacuator which is handled by the nurse. Since many dentists cannot count upon continuous chairside assistance during work with dental amalgam a new instrument, combining the functions of a common dental mirror and an evacuator has been developed. The aim of the present work was to evaluate the mercury vapor evacuating capacity of the new instrument. The study was carried out in a model box especially designed for the in vitro tests performed. The amount of mercury in an area representing the patient's breathing zone was recorded directly and indirectly using an equipment based on atomic absorption spectrophotometry. The results revealed that the new instrument has the capacity for substantially reducing the mercury levels during filling, polishing and cutting amalgam. Thereby the short transitory exposure to mercury vapor during certain working moments can be reduced which should be beneficial both to the patient and to the dental staff.
Air Pollutants, Occupational↗
Comparison of release of mercury from three dental amalgams.
Mercury release from dental amalgams has generated considerable concern in recent years and is the subject of this study. Specimens of one admixed high-copper amalgam (Contour), one lathe-cut low-copper amalgam (SDI), and a new tin- and copper-free amalgam claimed to be non-mercury-releasing (Composil) were evaluated for release of mercury when incubated in purified water at 37 degrees C. Measurement of mercury was done by cold-vapor atomic absorption spectrophotometry, and the amount released was expressed as micrograms/cm2/24 hr. Study was conducted over a four-week period. Results show that Contour and SDI released similar insignificant amounts (mean release of less than 0.1 microgram/cm2/24 hr) compared with Composil (mean release of 41.0 micrograms/cm2/24 hr). The difference in release by Composil compared with that by Contour and SDI is highly significant (P less than 0.001). The implications of chronic release of mercury from dental amalgams are discussed. Long-term release studies are in progress.
Dental Amalgam↗
Alloys for dental amalgam containing fluoride. Council on Dental Materials and Devices.
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American Dental Association↗
[Use of mercury in dental amalgam and sewage treatment at dental clinics].
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Dental Amalgam↗
Physical and mental health related to dental amalgam fillings in Swedish twins.
In the past years increasing attention has been paid to possible adverse health effects of mercury exposure from dental amalgam fillings. To evaluate possible health effects from amalgam fillings, dental status registered by specially trained nurses was obtained from 587 subjects included in the ongoing Swedish Adoption/Twin Study of Aging (SATSA). Data on physical and mental health were collected and memory function tested. Mean age was 66 years (SD 9, range 46-89). In the entire material, 25% of the individuals had no own teeth and in the group with own teeth the median number of teeth surfaces filled with dental amalgam was 15 (range 0-65). Analyses of associations between number of surfaces filled with dental amalgam and a number of scales estimating somatic and mental health and memory functions were performed both for the entire group and for individuals having at least 12 teeth. Regardless of the sample, no negative effects on physical or mental health were found from amount of dental amalgam, even after controlling for age, gender, education and number of remaining teeth. When using a co-twin control design with twin pairs discordant for amalgam exposure, no negative health effects associated with dental amalgam were detected. This study does not indicate any negative effects from dental amalgam on physical or mental health or memory functions in the general population over 50 years of age.
Age Factors↗
Dental amalgam and mercury.
This paper looks at the issues of the current amalgam controversy: the daily dose of mercury from amalgam, hypersensitivity to mercury, claims of adverse effects from amalgam mercury and alleged overnight "cures." In addition, the toxicity and allergenicity of the proposed alternative materials are examined with the same kind of scrutiny applied by the anti-amalgam group to dental amalgam.
Air Pollutants↗
Corrosion potential recovery of dental amalgam restorations following prophylaxis.
OBJECTIVE: Dental amalgam restorations are subjected to abrasion during selective prophylaxis that can damage or remove the protective oxide and result in increased rates of corrosion and chemical dissolution of mercury. It was the objective of this research to study the corrosion potential change of dental amalgam restorations to obtain an indication of the time required for in vivo repassivation following prophylaxis. METHODS: The corrosion potentials of 27 Class I and Class II amalgam restorations were measured pre- and post-prophylaxis using a high impedance voltmeter and a Ag/AgCl micro-reference electrode. Prophylaxis was performed for approximately 2s on each amalgam surface using a slow-speed handpiece with a rubber-cup and commercial abrasive paste. Subjects thoroughly rinsed before the post-prophylaxis corrosion potentials were measured. The data were analyzed using a confidence interval, a t-test and correlation analysis. RESULTS: The pre- and post-prophylaxis mean corrosion potentials were, respectively, -132 (27)mV and -126 (27)mV. The mean of the differences between the pre- and post-prophylaxis corrosion potentials was 6.1 (28)mV, with an associated 95% confidence interval of (-4.8, 17)mV. A t-test showed the mean absolute difference in corrosion potential was less than 50 mV (p<0.0001). SIGNIFICANCE: The results of this study show that the post-prophylaxis recovery of the corrosion potential of amalgam restorations occurred by at most 10-44 min, indicating that the period of elevated corrosion rate and elevated chemical dissolution rate of mercury, due to oxide damage or removal, may be short-lived.
Adult↗
A 7-year prospective quasi-experimental study of the effects of removing dental amalgam in 76 self-referred patients compared with 146 controls.
BACKGROUND: Dental amalgam has been suggested to cause long-term physical and mental problems. Claims that removal of the amalgam may lead to dramatic improvements in health have not been tested empirically in controlled studies with a long follow-up period. PURPOSE: To investigate the long-term effects of removal of dental amalgam on physical and mental symptoms in self-referred patients who complained of multiple somatic and mental symptoms attributed to dental amalgam fillings. METHODS: In a quasi experimental study, changes in the mental and physical symptoms in 76 patients who had their dental amalgam removed 7 years ago were compared with changes in symptoms among patients with known chronic medical disorders seen in alternative (n=51) and ordinary (n=51) medical family practices and noncomplaining patients with similar amounts of dental amalgam fillings (n=44) seen in an ordinary dental practice. The assessments included written self-reports, a 131-item somatic symptom checklist, Eysenck Personality Questionnaire (EPQ), the General Health Questionnaire (GHQ) and Toronto Alexithymia Scale (TAS). RESULTS: Subjects who removed their dental amalgam reported reduced physical and mental symptom load compared to status prior to removal, but only to a level comparable with that reported by the other groups with chronic medical disorders. The dental control group consistently reported lower symptom load during the whole period. In a hierarchical three-step regression model, pretreatment physical symptom load (P<.01), age (P<.10) and removal of dental amalgam (ns) predicted 26% of the variance in posttreatment physical symptom load. CONCLUSION: In a self-referred group of subjects with health complaints attributed to dental amalgam who remove their dental amalgam, the symptom load at follow-up corresponds to the level seen in chronic medical disorders despite the strong implicit placebo effect of the present quasi-experimental design. The finding does not support the hypothesis that removal of dental amalgam will reduce health complaints to normal levels and seriously questions the hypothesis that dental amalgam is an important cause of distress and health complaints.
Adolescent↗