Dental amalgam, sometimes referred to as “silver filling,” is a silver-colored material used to fill (restore) teeth that have cavities. Dental amalgam is made of two nearly equal parts: liquid mercury and a powder containing silver, tin, copper, zinc and other metals. Amalgam is one of the most commonly used tooth fillings, and is considered to be a safe, sound, and effective treatment for tooth decay.
When amalgam fillings are placed in or removed from teeth, they can release a small amount of mercury vapor. Amalgam can also release small amounts of mercury vapor during chewing, and people can absorb these vapors by inhaling or ingesting them. High levels of mercury vapor exposure are associated with adverse effects in the brain and the kidneys.
Since the 1990s, several federal agencies have reviewed the scientific literature looking for links between dental amalgam and health problems. According to the Centers for Disease Control and Prevention (CDC), there is little scientific evidence that the health of the vast majority of people with dental amalgam is compromised, nor that removing amalgam fillings has any beneficial effect on health.
The U.S. Food and Drug Administration announced plans to hold an advisory panel on Dec. 14-15, 2010, to discuss several scientific issues that may affect the regulation of dental amalgam, used for direct filling of carious lesions or structural defects in teeth. The panel meeting will focus particularly on the potential risk to vulnerable populations, such as pregnant women, fetuses, and young children.
Used to treat tooth decay, dental amalgam is a mixture of metals, composed of liquid mercury and a powdered amalgam alloy, composed primarily of silver, tin, and copper.
On July 28, 2009, the FDA issued a final rule that reclassified dental mercury from a class I device to class II, classified dental amalgam as a class II device, and designated special controls for dental amalgam, mercury and amalgam alloy. The special control for the devices is a guidance titled, "Class II Special Controls Guidance Document: Dental Amalgam, Mercury and Amalgam Alloy."
Since that time, the agency has received several petitions raising various issues relating to the final rule and special controls.
The concerns raised include the adequacy of the risk assessment method used by the FDA in classifying dental amalgam, the bioaccumulative effect of mercury, the exposure of pediatric populations to mercury vapor, and the adequacy of the clinical studies on dental amalgam. In addition, a recent report on risk assessments issued by the National Academy of Sciences, titled "Science and Decisions: Advancing Risk Assessment, NAP 2009," proposes new approaches to conducting risk assessments. These may be some of the issues the agency asks the advisory committee to review.
