Which radiographic sign is typically associated with early occlusal caries before dentin involvement?

• A. A thin radiolucent line beneath enamel
• B. A diffuse radiopaque band in enamel
• C. A radiopaque line along the restorative margin
• D. A circular radiolucent area near the CEJ

Answer: (A)

Early enamel caries show up on radiographs as a subtle radiolucent change within the enamel, not a deep cavity. On bitewing images, you can often see a thin dark line just beneath the enamel surface in the occlusal fissure area, representing subsurface demineralization that has not yet reached dentin. This slender radiolucent band indicates the lesion is still confined to enamel and hasn’t progressed to dentin, which would produce a more extensive radiolucency.

The other patterns don’t fit this stage. A diffuse radiopaque band in enamel would not be caries, since caries are radiolucent from mineral loss. A radiopaque line along a restorative margin points to a restoration material or margin, not an early enamel lesion. A circular radiolucent area near the CEJ suggests cervical or root-area pathology, not an early occlusal enamel lesion.