What is the most reliable chairside method of confirming that PULPAL anesthesia has been achieved in a mandibular molar before beginning endodontic access?

Correct answer: A. Cold testing the tooth itself and obtaining no response

• A. CORRECT. COLD TESTING THE TOOTH is the only method that tests the pulp itself. A tooth that gave a positive response before the block and gives NO response afterwards has genuine pulpal anesthesia. This matters because the failure rate of the IAN block in symptomatic irreversible pulpitis is high, and profound soft-tissue numbness does not guarantee a quiet pulp.
• B. Palpation assesses periapical and periosteal tenderness, which again is not a test of pulpal anesthesia.
• C. Lip and tongue numbness confirm only that the inferior alveolar and lingual nerves have been reached at the mandibular foramen. Numb lip with a still-sensitive pulp is the classic 'hot tooth' scenario and the commonest cause of an unexpectedly painful access.
• D. Percussion tests the PERIODONTAL LIGAMENT and periapical tissues, not the pulp — and it is not abolished by a conventional block.

Note: If cold still elicits a response after a successful-feeling block, supplement: buccal infiltration with articaine, an intraligamentary injection, an intraosseous injection, or an intrapulpal injection once the chamber is entered.