Which type of nerve fiber is activated during a cold test on a tooth?

Correct answer: A. A-delta fibers (myelinated)

• A. Correct. A-delta fibers are myelinated, fast-conducting fibers responsible for the sharp, immediate, well-localized response elicited by a cold pulp test.
• B. C fibers transmit slower, dull, lingering pain — more relevant to irreversible pulpitis's lingering pain pattern than the immediate cold test response itself.
• C. A-beta fibers primarily transmit touch/pressure, not the pain response to cold testing.
• D. B fibers are autonomic, not relevant to the sharp pain response of cold pulp testing.