What is interproximal burn-out and how does it appear on radiographs?

• A. Dentin artifact that mimics caries; radiolucent but outlined by normal anatomy
• B. A true caries lesion
• C. Radiopaque feature due to enamel
• D. Not seen on radiographs

Answer: (C)

Interproximal burn-out is an imaging artifact caused by the dense enamel seen in the space between adjacent teeth. On radiographs, particularly bitewings, the enamel on the contacting surfaces attenuates the X-ray beam more strongly, so the interproximal zone can appear as a radiopaque (bright) feature. This is not decay; it’s a normal-appearing area produced by how enamel density and beam geometry interact on the image. True caries would show up as radiolucent (dark) areas because mineral loss reduces attenuation, often starting at the contact point and progressing toward the dentin. So the radiopaque appearance here is due to enamel and image formation, not pathology.