Mercury

The content of particulate matter and mercury vapor in dentist breathing air during removal of amalgam restorations was assessed. Mercury and silver were quantitatively assayed by nuclear chemical analysis, and the mercury vapor concentration was measured with a sniffer. When the water spray was not used, the short time threshold limit values for exposure to mercury and silver were exceeded about 10 times. With water spray the mercury content was reduced to a level considerably lower than the threshold limit value, whereas the silver concentration slightly exceeded the corresponding limit.

The galvanic currents between gold and amalgam were determined in vitro in aerated artificial saliva kept at 37 degrees C. Using conventional amalgam, the current between gold and amalgam was rapidly fluctuating, and both the magnitude of this fluctuation and the maximum current density increased with increased ratio between the gold and the amalgam surface area (G/A). The current density exhibited by the non-gamma 2 amalgam was lower, independent of G/A, and showed no fluctuations.

“It would appear, therefore, that the merthiolate which is used as a preservative in a commercially available gammglobulin preparation represents a potential hazard to patients receiving chronic parenteral therapy with gammaglobulin.”

Not available.

“Three human subjects ingested 1065 ml of beer equivalent to 65 ml of ethanol 30 min before exposure (12-20 min) to mercury vapor. An additional two subjects were exposed to mercury vapor without ethanol pretreatment. The results show that alcohol brings about: 1) reduced mercury retention, 2) an increase in the rapid phase of vapor loss by expiration, 3) an increased mercury storage in the liver, 4) a marked reduction in mercury uptake by the red blood cells and 5) the abolition of vapor exposure experiments were performed by using control and ethanol-pretreated mice and rats. Sacrifice occurred at 1 hr and 3 days. The results support and extend the human data.”

“The retention of 203Hg was studied six days after a single oral or intraperitoneal administration to six week old female albino rats fed rat’s diet or milk. After oral administration rats on milk diet had a two times higher retention of mercury in the gut-free carcass and a 23 times higher retention in the gut than animals on rat’s diet. Changes in diet had very little influence on mercury retention after intraperitoneal administration. The higher gut and carcass rentions of mercury in animals on milk diet could be prevented or reduced by transferring rats from milk diet to rat’s diet several days after an oral dose of mercury. These results might be relevant for interpreting high gut and carcass retention after oral administration of some metals in suckling and changes which occur at weaning.”

“A list of compounds which depleted glutathione and induced lipid peroxidation and cell lysis is given.”

“While examining the exposure of dental patients to elemental mercury via dental restorations,³ we noticed that chewing, after teeth had been filled with a silver-mercury amalgam, was accompanied by an increase in the amount of elemental mercury breathed out by the patient.”

Among 1,128 patients with oral leukoplakia and 326 patients with oral lichen planus included in long-term follow-up studies, thirty-two patients showed lesions of the oral mucosa which could be attributed to electrogalvanism. The material consisted of twenty female and twelve male patients. The clinical diagnosis was leukoplakia in sixteen patients and oral lichen planus in the remaining sixteen patients. Histopathologic characteristics were analyzed and correlated to the clinical findings. In five cases malignant transformation developed. The term electrogalvanic white lesions is suggested as a common denominator for these mucosal changes, which seem to take the shape of lichen planus as often as that of leukoplakia.

“Concentrations of Cd (475 samples), Pb (271), and total Hg (166) were determined in the organs and tissues during autopsies of inhabitants of the Tokyo metropolitan area who had experienced no known exposure to an abnormally high level of heavy metals and had died sudden deaths by accident. The results of this study do not differ greatly from those of other reports. Based on the intraorganic accumulation of the heavy metals according to age when they were not experimentally administered, the biological half-time (BHT) was estimated using a mathematical model with differential equations. It was hypothesized that the input of heavy metals into organs is proportional to the amount of food intake according to age (assuming little or no chronological change of heavy metals concentrations in food over several decades), and that the output is proportional to the intraorganic accumulation. The resulting BHT was very long, 10 to 100 times that computed in a number of studies from observation of the attenuation curve for a relatively short period after the experimental administration of heavy metals to humans or animals.”