National Dental Assisting Examining Board (NDAEB) Practice Exam

What are the main components of dental amalgam?

1. Liquid mercury and metal alloy

2. Composite resin and glass ionomer

3. Gold and porcelain

4. Sodium fluoride and calcium carbonate

The correct answer is: Liquid mercury and metal alloy

The main components of dental amalgam are liquid mercury and metal alloy. Dental amalgam is a material commonly used in restorative dentistry, specifically for filling cavities resulting from tooth decay. The combination of liquid mercury with powdered metals such as silver, tin, and copper creates a durable and malleable substance that can withstand the forces of chewing. Liquid mercury acts as a binding agent that allows the metal alloy particles to adhere to one another, forming a cohesive mixture that can be shaped and fitted into the cavity. Once the amalgam is placed in the cavity and allowed to set, it hardens into a resilient restoration that can last for many years. This unique combination of materials provides excellent physical properties, making dental amalgam a reliable choice for posterior teeth where strength is crucial. In contrast, other materials mentioned in the other options, such as composite resin and glass ionomer, are different types of restorative materials utilized for various dental applications, each with distinct properties and uses. Gold and porcelain are also alternative materials for dental restorations but do not make up the composition of dental amalgam, and sodium fluoride and calcium carbonate are not relevant in the context of dental amalgam composition.