Dental amalgam is a product used for restoring teeth by filling them after they have been drilled to remove dead and infectious material. Also known as a “silver filling,” a reference to the color and one of the ingredients, this product is one among a range of options for filling teeth and its use is in decline. The inclusion of elemental mercury in the metal alloy used for dental amalgam has raised health concerns, and some people dislike it on aesthetic grounds, as it does not blend with the teeth. There are a number of alternatives like resins, cements, and ceramics available for dental fillings.
The earliest evidence of the use of silver in dental restoration dates to the seventh century in China. By the 1800s, dentists had developed dental amalgam and were starting to use it in their practices. The amalgam contains between 43-54% elemental mercury, blended with metals like tin, copper, silver, and zinc in varying amounts. Manufacturers of dental amalgam supply it in capsules mixed by dentists as needed.
Advantages of dental amalgam include low cost and very high durability. The mercury also inhibits the growth of bacteria, making a recurrence of tooth decay less likely. Research by a number of medical organizations indicates that dental amalgam is generally safe for use in people over the age of six, although pregnant women should avoid this product and all dental work in general, if possible. There are some environmental concerns about disposal of waste amalgam and release of mercury into the air when people with silver fillings are cremated.
Many people think of mercury as extremely toxic and dangerous, and this fuels many of the health concerns about dental amalgam. As long as the filling remains sealed and static, patients should stay safe, although they will inhale some mercury vapor during the process of placing the filling. Organizations like the American Dental Association recommend leaving amalgam fillings in place rather than removing and replacing them, unless there is a compelling reason to do so, like damage to the filling or a return of tooth decay.
When dentists are preparing for procedures where restoration will be required, they can discuss the filling options with their patients. Amalgam may be presented as a choice, but it will not be forced on patients who prefer to pursue other options. A dentist may have specific concerns about a particular case leading to a recommendation of a specific filling material like ceramic or a resin.