Efficacy and tolerability of an intraoral benzocaine patch in the relief of spontaneous toothache pain.

OBJECTIVE: In this randomized, double-blind, placebo-controlled clinical trial, the effectiveness and tolerability of a novel intraoral benzocaine patch was evaluated in 60 patients who presented to the Dental School's emergency clinic with spontaneous toothache pain of at least a moderate intensity. METHODOLOGY: Mucoadhesive patches, containing either 12 mg of benzocaine or a matching placebo, were applied approximately two millimeters apical to the mucogingival junction of the symptomatic tooth and remained in place for 60 minutes. Pain intensity (0-4 scale) and pain relief (0-4 scale) were recorded every five minutes through 30 minutes, and then every ten minutes through the 90-minute time point. The onset times of first perceptible and meaningful relief were recorded using two stopwatches. The occurrence of adverse events was also monitored. RESULTS: While the benzocaine patches were numerically superior to the placebo patches at all time points with respect to pain relief, PID (pain intensity difference) and their summed measures (TOTPAR and SPID scores), an analysis of covariance revealed no significant differences between treatments. Survival analysis indicated that the percentage of patients reporting meaningful pain relief by 30 minutes was significantly (p < 0.05) greater in the benzocaine group than in the placebo group (77% for benzocaine and 47% for placebo). The median onset times to first perceptible and meaningful relief were 5.4 and 18.1 minutes in the benzocaine group, and 7.8 and 30.4 minutes in the placebo group. Only two side effects (headache) were reported in the entire study. CONCLUSION: Although the results of the present study were promising, further research on this novel delivery system of benzocaine is warranted to firmly establish efficacy in patients with spontaneous toothache pain.