Dental Amalgam Annotated Bib

Dental Amalgam: Annotated Bibliography

Zahra Wali

Hol, P.J., Vamnes, J.S., Gjerdet, N.R., Eide, R., & Isrenn, R. (2001). Dental amalgam and selenium in blood. Environmental Research, 87(3), 141-146. doi:http://dx.doi.org/10.1006/enrs.2001.4308

It has been surmised that Selenium (Se) can protect against mercury (Hg) toxicity in humans thanks to the Hg-Se complex linked to selenoprotein P. In blood. The study in this peer-reviewed scientific journal measured Se concentrations in persons with health problems due to dental amalgam fillings. The Se concentrations of blood samples of 80 study participants were taken over the course of the study. Two groups were studied, one of which consisted of 21 healthy controls with amalgam fillings and 20 patients who claimed symptoms from existing amalgam fillings; the second of which consisted of 19 healthy controls with amalgam fillings and 20 symptomatic patients with the fillings. In the first group the concentration of Se in the blood was lower in a statistically significantly manner than healthy subjects but in the second group there was no statistically significant difference. However, the study concluded that it is possible that people who experience health problems related dental amalgam might have a Se metabolism different from those who do not and further research is warranted given the relatively small sample of the participants.

Given the lack of consistency of the results, the claim by the author that problems with dental amalgams and low selenium levels seems somewhat dubious. The study is in a scientific, rather than a dental journal, which points to its credibility and lack of bias, given that the authors have no apparent personal or financial interest in the results. But the study of the patients in total was extremely small. Each different grouping of approximately 20 experimental and 20 controls was very limited. There was no discussion of the different demographic data of the two groups of patients, which could have affected the result. Past psychological as well physical history could have affected the patient's perceptions of the impact of the amalgams upon their health. Also, there may be racial, gender, and other demographic variables in the two groups that could explain the radically different results. The 'logical' step would have been to at least replicate the experiment with a third group, given the inconsistent results, rather than to conclude that the hypothesis was confirmed merely because one symptomatic group had lower Se levels.

Huget, J. (2002, Mar 26). Filling in for mercury: There's no proof dental amalgam is unsafe but there are options for the wary. The Washington Post. Retrieved at:

http://www.highbeam.com/doc/1P2-334769.html