Radiology · single question
What is the caries progression score for the maxillary right first premolar shown in the radiograph (lesion appears to extend into dentin but not to the pulp)?
Show answer and explanation
Correct answer: B. E2
The radiographic caries scoring system: D1 = enamel only (outer half); D2 = enamel, inner half; E1 = extends into outer third of dentin; E2 = extends into middle third of dentin. A lesion that has crossed the DEJ and penetrated into the middle third of dentin is scored E2. This correlates with a lesion needing immediate restoration.
- A. INCORRECT. E0 would indicate no radiographic evidence of caries.
- B. CORRECT. E2 indicates caries extending into the MIDDLE third of dentin. This is the appropriate score for a lesion visible into dentin but not yet at the pulp.
- C. INCORRECT. E1 indicates the caries lesion extends into the OUTER third of dentin (just past the DEJ).
- D. INCORRECT. D1 refers to caries in the outer half of enamel only — not involving dentin.