Hypoalgesic effect of EMLA and lidocaine gel applied on human oral mucosa: quantitative evaluation by sensory and pain thresholds to argon laser stimulation

Sensory and pain thresholds to argon laser stimulation were used to evaluate the analgesic efficacy and duration of a eutectic mixture of local anesthetics (EMLA) and a 2% lidocaine gel applied topically on the oral mucosa. Application of EMLA for 2 min on the tongue and gingiva increased the pain thresholds by 92.8% and 63.4% respectively. Corresponding values for lidocaine gel were 53.6% and 21.9%. Standardized variation of the EMLA application period (2, 5, and 15 min) produced significantly different analgesic profiles on the tongue but not on the gingiva. Application of EMLA for 5 and 15 min on the tongue and for 2, 5, and 15 min on the gingiva increased the pain thresholds to a predefined analgesic level (2.15 W) for 2 to 25 min. The present experimental model for assessment of oral mucosa pain is suggested to be well-suited for investigations of intraoral analgesia.