This paper reviews the peer-reviewed and scholarly literature on dental amalgam, a widely used restorative material composed of approximately 50% mercury. The review examines the historical use of amalgam, growing scientific concerns about mercury exposure—particularly for children and pregnant women—and the regulatory responses from the U.S. FDA and the American Dental Association. Key studies are assessed, including longitudinal research demonstrating dose-dependent relationships between amalgam exposure and urinary mercury levels. The paper also considers why mercury-based amalgam remains prevalent despite known risks, and evaluates composite resin as a viable alternative, concluding that cost, convenience, and required retraining are primary barriers to adoption of safer materials.
The paper demonstrates systematic literature synthesis: each cited study is contextualized within a broader argument rather than merely summarized in isolation. The author connects findings across studies (e.g., linking the Casa Pia Trial results to Geier et al.) to build a cumulative evidentiary case, a technique central to effective literature reviews in health and medical sciences.
The paper opens with a framing introduction that states the research problem and scope. The body moves through historical background, escalating health concerns, regulatory frameworks, and specific empirical studies on children. A brief section addresses why amalgam persists despite risks, providing balance. The conclusion synthesizes key findings without introducing new material — a clean academic close appropriate for a literature review format.
Some of the most common dental restorative materials currently in use are dental amalgams, but these compounds contain approximately 50% mercury, making their use controversial — particularly with young children who may be harmed by long-term exposure. Although viable composite resin alternatives are available, dental amalgams with mercury remain the treatment of choice for many practitioners. To determine the current risks and potential alternatives to dental amalgams, this paper reviews the relevant peer-reviewed and scholarly literature concerning these issues, followed by a summary of the research and important findings in the conclusion.
Dental amalgams are a commonly used dental restorative material, but amalgams contain a number of compounds including mercury (Hg) (Geier, Carmody, Kern & King, 2011). A report from Bradbard (1999) notes that despite the mercury content, dental amalgam has a long track record of use. As Bradbard explains, "Amalgam restorations, better known as 'silver fillings,' are the most widely used material to fill cavities in decayed teeth, technically known as caries. It has been used for 150 years; only gold has been used longer" (p. 22). Although mercury is the main component of dental amalgam, the compound contains a number of other metals and alloys as well. Bradbard reports, "Amalgam is composed of approximately equal parts of liquid mercury and alloy powder containing silver, tin, copper, and sometimes lesser amounts of zinc, palladium or indium" (p. 23).
Notwithstanding its lengthy track record, dental amalgam is increasingly viewed with concern by researchers and clinicians alike. According to Bradbard, "Despite amalgam's long history of use, some scientists and consumers are concerned that the mercury from amalgam restorations might be harmful. Nearly half of 1,000 adult Americans surveyed by the American Dental Association said they believed amalgam could cause health problems" (p. 23). A more recent American Dental Association survey determined that posterior composite resin restorations are currently more popular than amalgam restorations, at least in the United States; however, dental schools in different countries differ significantly in the methods they teach for use of composite resins (Ben-Gal & Weiss, 2011).
Voynick (2004) notes that other countries are reevaluating the efficacy and safety of mercury-based amalgams for dental applications. According to Voynick, "Austria, Denmark, Germany, and Sweden are already phasing out the use of dental amalgam, and in the United States and Canada, many dentists have voluntarily discontinued its use" (p. 144). In fact, the European Union has taken steps to completely ban all mercury-based dental amalgams. A report presented to the European Parliament cites the known dangers associated with even minute amounts of mercury exposure to pregnant women and young children. According to the editors of European Social Policy, "EU health and environment experts are demanding that all use of mercury, particularly in medical devices, be banned. Mercury has long been recognized as a major source of toxicity in children causing reduced cognitive functioning, including reduced IQ" (Public health: Experts call for a total ban on mercury, 2007, p. 79).
Despite these trends in other countries, the American Dental Association has largely maintained its support for mercury-based amalgams. The ADA's position statement indicates that besides "rare instances of local side effects of allergenic reactions, the small amount of mercury released from amalgam restorations, especially during replacement and removal, has not been shown to cause any adverse health effects" (quoted in Voynick, 2004, p. 144). The ADA further states that the organization "finds no justification for discontinuing the use of dental amalgam," a perspective mirrored by the U.S. Public Health Service (Voynick, 2004, p. 144).
The concern over dental amalgam is certainly not new. According to Robicsek (2002), "The mercury issue goes back at least to 1850, and no one has conclusively shown that mercury fillings are safe" (p. 8). This lack of certainty became even more pronounced during the late 20th century as clinicians gained additional experience with these materials. Robicsek (2002) recounts the testimony of dentist Mark A. Breiner, author of Whole Body Dentistry: "I had learned in dental school that amalgams were perfectly safe and posed no threat whatsoever to human health. In 1978, my dental assistant's five-year-old daughter had her first cavity. I placed her first mercury amalgam filling. Two days later she had a seizure. Having faith in the ADA, I was stunned to find an abundance of documented research and scientific data that called into question the safety of amalgam use" (p. 8).
In response to growing concerns about the safety of amalgam alloys, the U.S. Food and Drug Administration issued a final rule in 2006 classifying dental amalgam into class II. The final rule also reclassified dental mercury from class I to class II and designated a special control to support the class II classifications of these two devices together with the existing class II classification of amalgam alloy (Dental devices, 2006). At present, all three dental devices are classified under a single regulation (Dental devices, 2006). A guidance document published by the FDA entitled "Class II Special Controls Guidance Document: Dental Amalgam, Mercury, and Amalgam Alloy" currently serves as the special control instructions for these devices (Dental devices, 2006). Total replacement is currently the most common method used for defective amalgam restorations and represents a major component of restorative dental treatment, with repair of these devices serving as an alternative for amalgam restorations characterized by localized defects (Popoff, Gonzales, Magalhaes, Moreira & Ferreira, 2011).
Bradbard, L. (1999). Dental amalgam: Filling a need or foiling health? FDA Consumer, 27(10), 22–24.
Food and Drug Administration. (2009, August 4). Dental devices: classification of dental amalgam, reclassification of dental mercury, designation of special controls for dental amalgam, mercury, and amalgam alloy. Final rule. Federal Register, 74(148), 38685–38714.
Geier, D.A., Carmody, T., Kern, J.K., King, P.G. & Geier, M.R. (2012, January). A dose-dependent relationship between mercury exposure from dental amalgams and urinary mercury levels: a further assessment of the Casa Pia Children's Dental Amalgam Trial. Human & Experimental Toxicology, 31(1), 11–17.
Maserejian, N.N., Trachtenberg, F.L., Assmann, S.F. & Barregard, L. (2008, February). Dental amalgam exposure and urinary mercury levels in children: The New England Children's Amalgam Trial. Environmental Health Perspectives, 116(2), 256–261.
Popoff, D.A., Gonzales, F.S., Magalhaes, C.S., Moreira, A.N. & Ferreira, R.C. (2011, November–December). Repair of amalgam restorations with composite resin and bonded amalgam: a microleakage study. Indian Journal of Dental Research, 22(6), 799–803.
Public health: Experts call for a total ban on mercury. (2007, January 17). European Social Policy, 79.
Robicsek, J. (2002, September 1). Does the ADA need a root canal? E. Magazine, 13(5), 8–10.
Voynick, S. (2004, May). Mercury in the body. The World and I, 19(5), 144.
Woods, J.S., Martin, M.D. & Leroux, B.G. (2007, October). The contribution of dental amalgam to urinary mercury excretion in children. Environmental Health Perspectives, 115(10), 1527–1530.
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