iaomtlibrary

“We tested the 10 known or suspected spindle poisons (colchicine, econazole nitrate, chloral hydrate, hydroquinone, diazepam, thiabendazole, cadmium chloride, thimerosal, pyrimethamine and vinblastine) of the coordinated EEC programme for induction of aneuploidy with the in vitro porcine brain tubulin assembly assay. The influence of the compounds on different parameters [lag-phase, polymerization velocity, endabsorption (steady-state level), reversibility, influence on disassembly at 4 degrees C] was evaluated. Colchicine [IC30 (30% inhibition concentration): 0.002 mM), vinblastine (IC30: 0.002 mM), thimerosal (IC30: 0.03 mM), thiabendazole (IC30: 0.5 mM) and chloral hydrate (IC30: 60 mM) led to an inhibition of tubulin assembly in vitro. No influence on the steady-state level was obtained with econazole nitrate (up to 0.1 mM), diazepam (up to 2.5 mM), cadmium chloride (up to 1 mM), pyrimethamine (up to 1 mM) and hydroquinone (up to 25 mM), the highest dose tested being limited either by precipitation or by reaching the maximal solubility of the compound in the solvent used. Diazepam enhanced the lag-phase and slightly reduced the polymerization velocity dose-dependently; however, all the treated test mixtures reached the same end absorption levels as the control. The influence on the disassembly process was studied at 4 degrees C. Microtubules treated with colchicine, econazole nitrate, diazepam, thiabendazole, cadmium chloride, thimerosal and pyrimethamine reached the same end absorption level after disassembly as the untreated control. Chloral hydrate reduced the disassembly rate but the end absorption of the control was not reached, the 30% reduction concentration being 0.25 mM. Hydroquinone at very high doses (greater than 10 mM) stimulated the disassembly process..”

“This paper reviews the facts available on the biological effects of mercury released from amalgam restorations in teeth. There seems to be no doubt that mercuric vapor is released from restorations, but we do not know how much of this mercury is deposited in human tissues. There is no scientific evidence to support the belief that vapors from dental restorations either cause or exacerbate human diseases. Therefore, there is no clinical justification at present for replacing amalgam with other less durable or less predictable restorative materials.”

“…It is a filling, a silver amalgam filling, the dentist’s filling of choice for more than a century. More than a hundred million of them were put into American mouths last year.  What you probably don’t know is that these so-called silver fillings are 50% mercury, and mercury is more poisonous than even lead or even arsenic.”

“An aerosol that contains amalgam particles is created when a high-speed hand-piece is used to remove an existing amalgam restoration. Those particles smaller than 10 microns are considered to be fully respirable. This means that a significant percentage of the particles have the potential to travel to the terminal alveoli, where they may become lodged. Long-term exposure to fully respirable particles may compromise a person’s respiratory function. Amalgam restorations were placed in the typodont teeth of a mannequin designed to simulate the head and the respiratory tract of a patient. The amalgam restorations were removed under three experimental conditions: dry cut (control), wet cut (water spray) with high-velocity evacuation, and wet cut with high-velocity evacuation and a rubber dam. Particulate exposure was evaluated in the simulated respiratory tracts of the patient and the dentist that were equipped with ambient particle sizing samplers. Use of water spray and high-velocity evacuation significantly reduced patient exposure to particles. The use of a rubber dam, together with water spray and high-velocity evacuation, was responsible for a further significant reduction of exposure to particles when compared with water spray and high-velocity evacuation alone. The dentist, however, was exposed to moderate levels of fully respirable particles for all conditions tested. It is therefore recommended that all dental personnel wear face masks while removing existing amalgam restorations.”

“The fate of mercury (Hg) released from dental “silver” amalgam tooth fillings into human mouth air is uncertain. A previous report about sheep revealed uptake routes and distribution of amalgam Hg among body tissues. The present investigation demonstrates the bodily distribution of amalgam Hg in a monkey whose dentition, diet, feeding regimen, and chewing pattern closely resemble those of humans. When amalgam fillings, which normally contain 50% Hg, are made with a tracer of radioactive 203Hg and then placed into monkey teeth, the isotope appears in high concentration in various organs and tissues within 4 wk. Whole-body images of the monkey revealed that the highest levels of Hg were located in the kidney, gastrointestinal tract, and jaw. The dental profession’s advocacy of silver amalgam as a stable tooth restorative material is not supported by these findings.”

“The findings presented here suggest that mercury poisoning from dental amalgam may play a role in the etiology of cardiovascular disorders. Comparisons between subjects with and without amalgam showed amalgam-bearing subjects had significantly higher blood pressure, lower heart rate, lower hemoglobin, and lower hematocrit. Hemoglobin, hematocrit, and red blood cells were significantly lower when correlated to increased levels of urine mercury. The amalgam subjects had a greater incidence of chest pains, tachycardia, anemia, fatigue, tiring easily, and being tired in the morning. The data suggest that inorganic mercury poisoning from dental amalgam does affect the cardiovascular system.”

“Concentrations of 15 elements were determined by instrumental neutron activation analysis in brain, spinal cord, blood cells, serum and nails of Amyotrophic Lateral Sclerosis (ALS) patients and appropriately matched control subjects. Several significant imbalances were detected in trace element levels in ALS samples compared to control samples. Some of these changes are probably secondary to the loss of tissue mass, especially in spinal cord. However the widespread changes observed in Hg and Se levels in ALS tissues deserve special attention. The significance of these alterations in trace element levels in relation to the pathogenesis of ALS is discussed.”

“The strongest and most convincing support we have for the safety of dental amalgam is the fact that each year more than 100 million amalgam fillings are placed in the United States. And since amalgam has been used for more than 150 years, literally billions of amalgam fillings have been successfully used to restore decayed teeth.”

“The increase in new clinical materials with questionable biological properties and the corresponding increase in awareness in patients to health hazards from dental materials are two important problems of modern clinical dentistry. Based upon evidence from clinical research the hypersensitivity problems related to the use of silver amalgam and acrylic denture base materials are reviewed to define possible risk groups among dental patients. In silver amalgam therapy the main risk group is patients with contact lesions in the oral mucosa adjacent to the restorations, as this group exhibits a high frequency of skin sensitivity to mercury and other base materials in dental amalgam. Among denture wearers a corresponding risk group has been observed among patients with previous allergic diseases and burning mouth syndrome. In these cases a high incidence of skin sensitivity reactions to denture allergens has been observed, usually to methylmethacrylate monomer and formaldehyde. Some possible pathogenic mechanisms leading to a contact allergy of the oral mucosa in these patient groups are discussed.”