Human Exposure to Mercury and Silver Released from Dental Amalgam Restorations

Abstract

In 35 healthy individuals, the number of amalgam surfaces was related to the emission rate of mercury into the oral cavity and to the excretion rate of mercury by urine. Oral emission ranged up to 125 micrograms Hg/24 h, and urinary excretions ranged from 0.4 to 19 micrograms Hg/24 h. In 10 cases, urinary and fecal excretions of mercury and silver were also measured. Fecal excretions ranged from 1 to 190 micrograms Hg/24 h and from 4 to 97 micrograms Ag/24 h. Except for urinary silver excretion, a high interplay between the variables was exhibited. The worst-case individual showed a fecal mercury excretion amounting to 100 times the mean intake of total Hg from a normal Swedish diet. With regard to a Swedish middle-age individual, the systemic uptake of mercury from amalgam was, on average, predicted to be 12 micrograms Hg/24 h.

The German Environmental Survey 1990/1992 (GerES II): reference concentrations of selected environmental pollutants in blood, urine, hair, house dust, drinking water and indoor air

“…The number of teeth with amalgam fillings was a significant predictor for the mercury concentration in urine of the general population ( Becker et al, 1996 ) . This has also been shown in other studies (Akesson et al, 1991;Jokstad et al, 1992;Skare and Engqvist, 1994) .…”

Mercury derived from dental amalgams and neuropsychologic function.

“…Despite widespread concern about the safety of silver-mercury amalgam dental restorations (Skare and Engqvist 1994), there is little evidence regarding harm or safety in the general population. Dental amalgams have been used for over 150 years with no overt adverse effects.…”

Relationship between mercury levels in blood and urine and complaints of chronic mercury toxicity from amalgam restorations

“…Emission of elemental mercury into the oral cavity is reported to be correlated with the number of amalgam surfaces (regression coeffi cient 0.73). 17 Due to leaching mercury vapours can be inhaled and transferred to the lungs through breathing due to their presence in the ambient air and the metal can reach the gastro-intestinal tract through the saliva which carries the dissolved inorganic mercury or the abraded particles. Eley and Cox 18 and Mackert and Berglund 19 reviewed the consequences of mercury release from dental amalgam, its absorption accumulation and excretion by the body and ill-effects of cumulative storage.…”