# Which is most difficult to diagnose?
A. Necrosed pulp
B. Internal resorption
C. Chronic pulpitis
The correct answer is C. Chronic pulpitis.
Both necrotic pulp and chronic pulpitis are difficult to diagnose and can show varied symptoms.
Chronic pulpitis can be differentiated by its history of clinical symptoms.
Chronic pulpitis under a crown restoration is most difficult to diagnose.
This question is a direct pick from NBDE and the answer is Chronic Pulpitis.