The answer to whether dentists still use silver fillings is yes, although their use has significantly declined over the last two decades. These silver-colored restorations are technically known as dental amalgam, a material used in dentistry for over 150 years. Amalgam is a mixture of metals, primarily consisting of powdered silver, tin, and copper, bound together by liquid elemental mercury. While modern alternatives are now preferred, amalgam remains a viable option in specific clinical situations due to its proven track record. Selecting a material involves considering the restoration’s location, the patient’s health profile, and the filling material’s unique properties.
Defining Dental Amalgam and Its Current Use
Dental amalgam is a durable restorative material formed by mixing liquid mercury with a powdered alloy (approximately 40% silver, 32% tin, and 30% copper). The mercury binds the metal particles into a strong, pliable paste that hardens quickly into a solid filling. This chemical reaction, called amalgamation, creates a structure exceptionally resistant to the high biting forces found in the back teeth.
Amalgam offers distinct practical advantages over other filling types. It is highly durable, often lasting 10 to 15 years. Furthermore, it is the least expensive filling material available, making it an important option for patients with financial constraints or those receiving care through public health programs. Amalgam is also less technique-sensitive than other materials, allowing for easier placement where controlling moisture and saliva is challenging.
Safety Profile and Regulatory Stance
The central debate surrounding dental amalgam stems from its elemental mercury content, which releases trace amounts of mercury vapor over the lifespan of the filling. Major regulatory and health organizations, including the U.S. Food and Drug Administration (FDA) and the American Dental Association (ADA), have consistently reviewed the scientific evidence. Both organizations maintain that dental amalgam is a safe, durable, and effective restorative material for the general population.
The FDA recommends that certain vulnerable groups avoid the placement of new amalgam fillings as a precautionary measure. This restricted group includes:
- Pregnant women.
- Women who are planning to become pregnant.
- Nursing mothers.
- Children, particularly those under the age of six.
- Individuals with pre-existing neurological conditions.
- Individuals with impaired kidney function.
Existing amalgam fillings in good condition should not be removed unless medically necessary. Removing a sound filling can unnecessarily expose the patient to a temporary spike in mercury vapor and risk damaging the tooth structure.
Primary Alternatives to Amalgam Fillings
The decline in amalgam use is due to the effectiveness of alternative materials, primarily composite resin. Composite resin is made from a mixture of plastic resin and fine glass particles. The main draw of composite is its aesthetic advantage, as it can be matched to the natural color of the tooth, making the restoration virtually invisible.
Composite fillings also bond directly to the tooth structure, which requires the removal of less healthy tooth material compared to amalgam placement. Other alternatives include Glass Ionomer Cement (GIC), a tooth-colored material that releases fluoride, offering an advantage in preventing secondary decay. For larger restorations, dentists may use indirect materials like ceramic or gold inlays and onlays. Gold is known for its durability, often lasting 20 years or more, while ceramic offers high strength and aesthetic appeal.
Clinical Factors in Material Selection
Selecting the filling material is guided by several clinical and personal factors. The location and size of the cavity are primary considerations, as back teeth bearing heavy chewing forces require materials with greater compressive strength. Amalgam and gold remain preferred options for large restorations in posterior areas due to their longevity and ability to withstand high stress.
Aesthetic concerns heavily influence the decision, making tooth-colored composite resin the standard for visible front teeth. Dentists must also assess the patient’s ability to maintain a dry field during the procedure. Composite resin requires excellent moisture control to bond properly, whereas amalgam is more forgiving. Patient financial considerations and dental insurance coverage are also discussed, as amalgam is substantially less costly than composite, ceramic, or gold options.