Dental amalgam fillings, commonly known as “silver fillings,” have long been used to restore teeth affected by decay. Their safety has frequently been a subject of public discussion. This has led many to question whether these dental restorations pose a health risk. Understanding what dental amalgam is and what scientific bodies say about its use can clarify these concerns.
Understanding Dental Amalgam
Dental amalgam is a mixture of metals used to fill cavities. It consists of liquid elemental mercury and a powdered alloy of silver, tin, and copper. Approximately half of an amalgam filling’s weight is elemental mercury, which binds the alloy particles to create a strong, durable filling.
Amalgam has been a popular choice in restorative dentistry for over 150 years. Its use is due to its durability, low cost, and ease of application. Though called “silver fillings,” the mercury content allows the material to be molded before hardening.
Concerns Regarding Amalgam Fillings
The primary concern regarding amalgam fillings centers on the elemental mercury they contain. This mercury can release low levels of vapor, which can be inhaled and absorbed by the lungs. The amount released varies with the number and age of fillings, and activities like chewing or brushing. Temporary increases in vapor exposure also occur during placement or removal.
Elemental mercury is processed differently by the body than other forms, like methylmercury in fish. However, questions exist about potential health effects from chronic exposure. Studies suggest people with multiple amalgam fillings may have slightly higher mercury levels in blood or urine. While these levels are typically considered safe for the general population, mercury can accumulate in tissues like the brain and kidneys.
What Health Organizations Say
Leading health and dental organizations, including the U.S. Food and Drug Administration (FDA), the American Dental Association (ADA), and the World Health Organization (WHO), state that for most individuals, dental amalgam fillings are safe and effective. They indicate that minimal mercury exposure from amalgam is not associated with harmful health effects in the general population.
However, the FDA and ADA recognize certain populations who may be more susceptible to mercury exposure. These groups include pregnant women, women planning pregnancy, nursing mothers, children (especially those under six), and individuals with neurological impairments or kidney dysfunction. For these groups, the FDA recommends avoiding dental amalgam and discussing alternative treatment options with a dental provider.
Alternatives to Amalgam Fillings
Several alternative materials are available for dental fillings, each with distinct properties:
Composite resin fillings, often called “tooth-colored” or “white” fillings, are made from plastic resin reinforced with glass particles. They can be matched to natural tooth color, offering aesthetic advantages, and bond directly to the tooth structure.
Glass ionomer cement fillings are useful for smaller restorations or in pediatric dentistry. These materials release fluoride, which can help prevent further decay.
Porcelain (ceramic) fillings are custom-made in a dental laboratory. They offer high durability and a natural appearance, blending seamlessly with existing teeth.
Gold fillings, made from an alloy of gold and other metals, are known for exceptional durability and longevity, often lasting for decades. While highly resistant to wear, their metallic appearance and higher cost are considerations.
Considerations for Amalgam Removal
Health organizations do not recommend routine removal of serviceable amalgam fillings solely to prevent systemic disease. Scientific evidence does not support a health benefit from removing intact amalgam fillings. Removing existing amalgam fillings can also lead to unnecessary loss of healthy tooth structure.
The removal process itself can temporarily increase mercury vapor release. However, removal might be considered in specific situations: when a filling is damaged, if there is recurrent decay underneath, or in cases of a confirmed allergic reaction to amalgam components. Patients with concerns about existing amalgam fillings should consult a dental professional to discuss their individual circumstances and options.