What are Amalgams? (Openstax Chemistry 2e)
An amalgam is an alloy of mercury with one or more other metals. This is similar to considering steel to be an alloy of iron with other metals. Most metals will form an amalgam with mercury, with the main exceptions being iron, platinum, tungsten, and tantalum.
Due to toxicity issues with mercury, there has been a significant decrease in the use of amalgams. Historically, amalgams were important in electrolytic cells and in the extraction of gold. Amalgams of the alkali metals still find useful because they are strong reducing agents and easier to handle than pure alkali metals.
Prospectors had a problem when they found finely divided gold. They learned that adding mercury to their pans collected the gold into the mercury to form an amalgam for easier collection. Unfortunately, losses of small amounts of mercury over the years left many streams in California polluted with mercury.
Dentists use amalgams containing silver and other metals to fill cavities. There are several reasons to use an amalgam including low cost, ease of manipulation, and longevity compared to alternate materials. Dental amalgams are approximately 50% mercury by weight, which, in recent years, has become a concern due to the toxicity of mercury.
After reviewing the best available data, the Food and Drug Administration (FDA) considers amalgam-based fillings to be safe for adults and children over six years of age. Even with multiple fillings, the mercury levels in the patients remain far below the lowest levels associated with harm. Clinical studies have found no link between dental amalgams and health problems. Health issues may not be the same in cases of children under six or pregnant women. The FDA conclusions are in line with the opinions of the Environmental Protection Agency (EPA) and Centers for Disease Control (CDC). The only health consideration noted is that some people are allergic to the amalgam or one of its components.
Flowers, P., Theopold, K., Langley, R., & Robinson, W. R. (2019, February 14). Chemistry 2e. Houston, Texas: OpenStax. Access for free at: https://openstax.org/books/chemistry-2e
Research Article: Association between dental amalgam fillings and Alzheimer’s disease: a population-based cross-sectional study in Taiwan
Date Published: November 12, 2015 Publisher: BioMed Central Author(s): Yi-Hua Sun, Oswald Ndi Nfor, Jing-Yang Huang, Yung-Po Liaw. http://doi.org/10.1186/s13195-015-0150-1 Abstract: The potential effects of amalgam fillings on the development of Alzheimer’s disease (AD) are not well understood. The aim of the study was to evaluate the association between dental amalgam fillings and Alzheimer’s disease in … Continue reading
Research Article: Perinatal death and exposure to dental amalgam fillings during pregnancy in the population-based MoBa cohort
Date Published: December 7, 2018 Publisher: Public Library of Science Author(s): Lars Björkman, Gunvor B. Lygre, Kjell Haug, Rolv Skjærven, Rogelio Cruz-Martinez. http://doi.org/10.1371/journal.pone.0208803 Abstract: The aim was to gain knowledge regarding the risk of perinatal death related to exposure to dental amalgam fillings in the mother. Population-based observational cohort study. The Norwegian Mother and Child … Continue reading
Research Article: Amalgam tattoo versus melanocytic neoplasm – Differential diagnosis of dark pigmented oral mucosa lesions using infrared spectroscopy
Date Published: November 6, 2018 Publisher: Public Library of Science Author(s): Johannes Laimer, Raphael Henn, Tom Helten, Susanne Sprung, Bettina Zelger, Bernhard Zelger, René Steiner, Dagmar Schnabl, Vincent Offermanns, Emanuel Bruckmoser, Christian W. Huck, Hasan Ayaz. http://doi.org/10.1371/journal.pone.0207026 Abstract: Dark pigmented lesions of the oral mucosa can represent a major diagnostic challenge. A biopsy is usually … Continue reading