Which caries stages have dentin lesions that are more extensive than enamel lesions?

• A. All stages
• B. D1 and D2
• C. D2 and D3
• D. D1 only

Answer: (C)

Caries depth is described in layers: enamel stages (outer and inner enamel) and dentin stages (outer, middle, and pulpal dentin). When a lesion reaches dentin, it has progressed beyond enamel. Among these, the deeper dentin stages reflect greater destruction than the enamel lesion alone. D2 and D3 indicate middle and pulpal dentin involvement, meaning the caries extends well beyond the enamel lesion’s depth. In contrast, the outer dentin stage (D1) is still relatively shallow and may not exceed the enamel lesion’s extent. So the stages with dentin lesions more extensive than enamel lesions are D2 and D3.