The truth can be painful. Knowing that treatment may hurt in itself is unpleasant, almost painful.
"Does it hurt?" is to the point, sharp, painful.
"Tell me if you experience any pain" is in some ways more indirect, less sharp.
With neither set of words does the actual pain caused by the dentist's drilling become less painful, but the second set of words makes the thought of the pain less sharp.
Student or Learner