Dental Admissions Test (DAT) Practice Test

What are amalgam fillings primarily made of?

1. A mixture of metals including silver, mercury, copper, and tin

2. A composite of plastics and resin

3. Gold and silver alloys

4. A blend of ceramics and glass ionomers

The correct answer is: A mixture of metals including silver, mercury, copper, and tin

Amalgam fillings are primarily made of a mixture of metals that includes silver, mercury, copper, and tin. This combination is designed to provide a durable and long-lasting solution for dental cavities. Silver is a key component that contributes to the strength and corrosion resistance of the filling. Mercury serves as a binding agent that allows the other metals to combine into a workable paste that can be easily shaped to fit the cavity. Copper adds to the hardness and strength of the amalgam, while tin aids in the mixture's workability and helps to control the setting characteristics. The unique properties of these metals together create a filling material that can withstand the forces of chewing and provides effective restoration for tooth structure. This makes amalgam a widely-used material in restorative dentistry for posterior teeth where strength is particularly important. Other materials listed, such as plastics and resin, gold and silver alloys, or ceramics and glass ionomers, serve different purposes in dental applications, but they do not make up amalgam fillings.