Amalgam is the most common material used for fillings. Also known as silver filling it is a mixture of mercury and an alloy of silver tin and copper. Mercury makes up about 45-50 percent of the compound and is used to bind the metals together and to provide a strong hard durable filling. After years of research mercury has been found to be the only element that will bind these metals together in such a way that can be easily manipulated into a tooth cavity.
Dental amalgam has a 150-year proven track record and is still one of the safest durable and least expensive materials to a fill a cavity. It is estimated that more than 1 billion amalgam fillings are placed annually. Dentists use dental amalgam because it is easier to work with than other alternatives as well as its ability to withstand the pressure of a person chewing. Some patients prefer dental amalgam to other alternatives because of its safety cost-effectiveness and ability to be placed in the tooth cavity quickly however its lack of esthetics is a strong negative feature.
Dental amalgam is used in many areas and for individuals of all ages. One of its most common uses is in small-to moderate-sized cavities when moisture control is problematic and when cost is an overriding patient concern. It is also frequently used in tooth repair as a foundation for cast-metal metal-ceramic and ceramic restorations and in stress-bearing areas.
Dental amalgams have both distinct advantages and disadvantages as highlighted below.
ﾷ Least technique-sensitive of all restorative materialsApplicable to broad range of clinical situations Good long-term clinical performance Easy to manipulate for dentist Less time needed for placement compared to other restorative materials Initially corrosion products seal the tooth restoration interface and prevent bacterial leakage Direct material (one-appointment placement) Easy repair Long-lasting when placed under ideal conditions and in a conservative preparation may equal or exceed the longevity of cast restorations
DisadvantagesSome destruction of sound tooth structure Not esthetic Long-term corrosion at margins may cause breakdown. Potential for galvanic reaction Local allergenic potential Negative public perception of mercury toxicity
Although by far the most popular choice for dental fillings it is not the only option. Other options include; composites which are used for porcelain crowns and gold foil which is used in non-stress bearing situations.