Radiology Practice Test

Which dental material appears most radiopaque on an x-ray?

1. Composite

2. Amalgam

3. Ceramic

4. Resin

The correct answer is: Amalgam

Amalgam appears most radiopaque on an X-ray because it is composed of materials such as mercury, silver, tin, and copper, which are dense and absorb X-rays to a greater extent than many other dental materials. This property makes amalgam show up as a bright white area on radiographs, clearly distinguishing it from surrounding tissues and materials. Composite, while also radiopaque, is typically less so than amalgam because it often contains filler particles that do not provide the same level of radiopacity. Ceramic materials may exhibit varying degrees of radiopacity, but they usually do not reach the level of amalgam. Resin materials, on the other hand, are generally more radiolucent (allowing more X-rays to pass through) than amalgam and are therefore seen as darker on the X-ray. Hence, amalgam's composition and properties make it the most radiopaque among the listed options.