Shortest Duration LA — NDEB AFK MCQ

Correct answer: E — Mepivacaine 3% plain (without vasoconstrictor)

Mepivacaine 3% plain (without vasoconstrictor) provides the shortest duration of pulpal anaesthesia via infiltration — approximately 20-40 minutes for maxillary infiltration. However, it is the only commonly used amide LA that provides clinically useful anaesthesia without a vasoconstrictor (due to its mild intrinsic vasoconstrictive properties). It is useful when epinephrine is contraindicated or when short-duration anaesthesia is desired. Bupivacaine provides the longest duration (60+ minutes pulpal via infiltration).

Reference: Malamed – Handbook of Local Anesthesia, 7th ed., 2020