Buffered lidocaine 1%/epinephrine 1:100,000 with sodium bicarbonate (sodium hydrogen carbonate) in a 3:1 ratio is less painful than a 9:1 ratio: A double-blind, randomized, placebo-controlled, crossover trial.

Background: Neutralizing (buffering) lidocaine 1%/epinephrine 1:100,000 solution (Lido/Epi) with sodium hydrogen carbonate (NaHCO) (also called sodium bicarbonate) is widely used to reduce burning sensations during infiltration of Lido/Epi. Optimal mixing ratios have not been systematically investigated.

Objectives: To determine whether a Lido/Epi:NaHCO mixing ratio of 3:1 (investigational medicinal product 1) causes less pain during infiltration than a mixing ratio of 9:1 (IMP2) or unbuffered Lido/Epi (IMP3).