The efficacy of Emla and 5% lignocaine gel for anaesthesia of human gingival mucosa.

OBJECTIVE: To compare the analgesic effect of a mixture of 2.5% lignocaine and 2.5% prilocaine (Emla) with that of lignocaine gel alone for minor operations on the gingiva. DESIGN: Randomized double-blind trial. SETTING: Teaching hospital, UK. SUBJECTS: 10 healthy dental students (7 men and 3 women, 20-21 years old). INTERVENTIONS: Construction of a reservoir within a splint on each side of the mouth and insertion of splints. The volunteers acted as their own controls, and the sides used for each anaesthetic were chosen at random. MAIN OUTCOME MEASURES: Measurement of pressure-pain threshold by a standard technique. RESULTS: The median (range) duration of anaesthesia after Emla (22.5, 12-30) was significantly longer than after lignocaine alone (12.5, 0-25) (P=0.01), and the area under the curve for the pressure-pain threshold for Emla (2053, 199-4564) was significantly greater than for lignocaine alone (986, 169-2942) (P=0.01). CONCLUSION: Emla is a more effective topical anaesthetic agent than lignocaine alone. Although its duration of action is relatively short it is adequate for minor operations on the gingiva.