Dental fillings can be made of a variety of materials. For a long period of time, silver amalgam fillings (a mixture of various powdered metals such as silver and tin bound together by elemental mercury) were the norm. Almost as soon as amalgam fillings started being used, however, they were criticized as being toxic to humans because of the presence of mercury within them. But do these fillings really present a danger to dental patients, and if so, to what extent? Read on to find out.
Liquid mercury is the only known substance that can effectively bind together the alloy particles used for fillings to form a strong, hard, stable compound.
Mercury occurs naturally and is also introduced to the environment as a contaminant. It exists in three chemical forms: organic, inorganic, and elemental. Methylmercury, organic mercury, is the one found in fish and the most toxic. Inorganic mercury has a variety of uses and is not as dangerous as organic mercury as it cannot be absorbed through the digestive tract. Dentist offices use the last form of mercury, elemental mercury, also known as liquid or metallic mercury, in dental fillings. It is almost completely non-toxic when ingested orally because it cannot be absorbed through the digestive tract.
It is true that exposure to high levels of mercury can have adverse health effects, such as damage to the brain and kidneys. However, since the 1990s, several agencies (CDC, FDA, ADA) have concluded that amalgam fillings are safe for adults and for children six years and older. Although they can release small amounts of mercury vapor, which can then be inhaled, it was found that even in people with as many as 15 surfaces of amalgam fillings, detectable mercury levels were far below the lowest levels that could cause any harm. Additionally, clinical studies found no link between amalgam fillings and health problems.
Silver fillings have been successfully used to treat dental caries and other dental issues for years. They present no health dangers, but have become used less often simply because of aesthetic purposes – other materials are tooth-colored and are less conspicuous.