The relationship of application time to EMLA efficacy.

PURPOSE: This study compared the efficacy of 5% Eutectic Mixture of Local Anesthetics (EMLA) cream at application times of 3 minutes, 5 minutes, and 10 minutes to determine the most effective duration of topical anesthetic application on normal mucosa. A special instrument was used to apply pressure on the gingiva to obtain a threshold discomfort level in grams before and after the topical delivery.

METHODS: Twenty mL of EMLA cream or a placebo was placed on the maxillary anteriorregion using Beckman paper wicks in the form of discs. The gingiva was wiped dry to get the most effective absorption result. The discs were left on the gingiva for 3, 5, or 10 minutes and off for another 3 minutes. The instrument applied pressure progressively, and the pressure application was stopped when the subjects reported the initial feeling of discomfort.

RESULTS: The results indicated that 5% EMLA cream significantly reduced the pain threshold level with 3-, 5-, and 10-minute application times. There was no significant difference among the different durations of 5% EMLA application.

CONCLUSIONS: Use of 5% EMLA could be especially beneficial to pediatric patients and young adults who are needle phobic. Development of an EMLA patch with the proper pediatric dosages to prevent possible overdosage and side effects should be the aim of future research.