Mercury

“Decontamination of offices is difficult but essential. Mercury vapor suppressants should be used routinely by all dentists. Cleaning equipment should be confined to the dental office and should be replaced often. Air conditioner filters should be replaced often. Observation of spillage and contaminated cleaning equipment is a sign of significant exposure. Remedial action should be taken to reduce exposure. Medical assistance, including urinalysis for mercury, should be obtained.”

“To assure safe and healthful working conditions for working men and women; by authorizing enforcement of the standards developed under the Act; by assisting and encouraging the States in their efforts to assure safe and healthful working conditions; by providing for research, information, education, and training in the field of occupational safety and health; and for other purposes.”

“The purpose of this study was to evaluate the gingival histologic response to the commonly used restorative materials. Amalgam, silicate and resin, both polished and unpolished, were used for the test restorations.”

“The investigations described confirm the possibility that manifestations of skin sensitization may be related to amalgam restorations.  The complex amalgam product as well as mercury should be considered sensitizing factors although the other alloy components such as copper, silver and zinc should not be ignored.  Sensitization appears most frequently after the amalgam has been present in the mouth for more than 5 years.”

“A 42-year-old dental surgery assistant with at least a 20-year history of exposure to mercury developed a rapidly fatal nephrotic syndrome. The high levels of mercury in the kidney, estimated by neutron activation analysis and demonstrated histologically, indicate that this was the result of mercury intoxication. Some unique features of the case are described and discussed. The warning is given that the risks of exposure to mercury in the dental surgery are not trivial.”

“Pertussis vaccines preserved with 0.01% Merthiolate are more toxic for mice than unpreserved vaccines prepared from the same parent concentrate and containing the same number of organisms. The toxicities of both Merthiolate (0.01%)-preserved and unpreserved vaccines increased when the number of organisms injected was increased. An increase in mortality was observed when Merthiolate was injected separately, before or after an unpreserved saline suspension of pertussis vaccine.”

“It is hypothesized that MS is a neuro-allergenic illness in which the allergen is a heavy metal—most often mercury, less often lead, and possibly also other metals. As a source of mercury the prevailing majority of cases is assumed to come from mercury in amalgam. After the compilation of the still unsolved riddles of MS, they are being compared with the hypothesis above. The conclusion is being drawn that none of the listed vulnerabilities is inconsistent with this hypothesis, and that most of the riddles (especially the geographic distribution, the age distribution and the historical evolution) may find their explanation in this.” [translation]

“Studies on the absorption of mercury vapour from the respiratory tract in four volunteers who breathed air with mercury concentrations ranging from 50 to 350 ug/m3 are reported. Determinations of the ratio of the expired to the inspired amounts of mercury gave an expression of the fraction that a notional dead space for mercury absorption represented of the average tidal volume measured during the experimental period. A comparison with the results reported by other authors on the size of the physiological dead space in relation to the tidal volume showed that the notional dead space for mercury absorption was of the same magnitude as the physiological dead space and, within the range investigated, largely independent of the mercury concentration in the inspired air. It was also demonstrated that the last part of the air expired during maximal expiration contained only negligible amounts of mercury. It is therefore reasonable to assume that almost complete absorption of mercury vapour occurs from the alveolar parts of the lungs in normal individuals.”

“Examination of 82 first-year medical and dental students at the University of Manitoba revealed a correlation between gingival disease and class II amalgam restorations with overhanging margins. In seven individuals there was more gingival disease in those who had good amalgam restorations on one side of the mouth and no amalgam restorations in contralateral teeth.”

“This report verifies the previous findings that silicate and amalgam restorations produce a chronic inflammation of the gingival sulcus epithelium. It also shows that cast gold restorations were well tolerated in the gingival sulcus area. The physical injury of cavity preparation adds another insult to the soft tissues, as demonstrated by the controls. This injury, however, is repaired within 30 days. The inflammation subsides, and the budding epithelial invaginations into the submucosa apparently subside to the normal microscopic anatomy of the dental epithelium. The mechanism of this sequence is well suited for future investigation.”