Which anatomical structures appear radiopaque on a dental radiograph?

The correct choice is based on a clear understanding of how different tissues and structures appear on a dental radiograph. Radiopaque structures are those that absorb radiation and appear lighter or white on the image. In dental radiography, these structures typically include hard tissues such as enamel, dentin, and bone.

Enamel, being the hardest substance in the human body, is highly radiopaque, which allows it to be easily identified on the radiograph. Dentin, while not as opaque as enamel, still has significant radiopacity due to its mineral content and is easily differentiated from softer tissues. Bone, which supports the teeth, also exhibits high radiopacity because of its dense mineral structure, particularly in areas such as the jaw.

In contrast, soft tissues and air spaces are radiolucent, which means they appear darker or transparent on a radiograph. Soft tissues, including nerves, do not significantly absorb X-rays, leading to their appearance as shadows on the image. Air, found in the oral cavity or sinuses, is another example of a radiolucent substance since it completely allows X-rays to pass through.

This understanding of the radiopacity of various structures helps in interpreting dental radiographs for diagnostic purposes. Hence, the presence of enamel,