A clinical evaluation of three topical anaesthetic agents.

This study compared the efficacy of EMLA 5% Cream, Xylocaine 5% (lignocaine 5 per cent) and NUM (benzocaine 15 per cent, amethocaine 1.7 per cent) to a placebo in reducing the pain experience during needle insertion. In a random, double blind study three groups of twenty volunteers each had a paired topical anaesthetic/placebo placed bilaterally in the buccal sulcus of the upper premolar regions for two minutes, followed by the insertion of a standard 27 gauge needle to a depth of 5 mm. Pain experience was measured with visual analogue scales. Results showed that all three agents significantly reduced pain when compared with the placebo--EMLA (p less than 0.002); Xylocaine (p less than 0.05); NUM (p less than 0.005).