Comparing the Efficacy of a Compound Topical Anesthetic Versus Benzocaine: A Pilot Study

To compare the effectiveness of a combination of 10% lidocaine, 10% prilocaine, and 4% tetracaine versus 20% benzocaine for use as a topical anesthetic agent prior to dental injections. A double-blind randomized prospective clinical trial was conducted with 26 participants receiving a topical anesthetic of 20% benzocaine (control) and 26 participants receiving a compound topical anesthetic mixture of 10% lidocaine, 10% prilocaine, and 4% tetracaine (experimental) prior to a maxillary infiltration injection. The procedure was conducted by 1 operator with the Wand® injection system. Pain was assessed directly with visual analog scale (VAS) scores and indirectly by measuring changes in heart rate at 4 different time points. Complications associated with the application of the topical anesthetics were also assessed. The experimental group had a significantly higher mean VAS score of 19.5 ± 19.7 mm versus 14.2 ± 14.6 mm for the control group (p < .001). No significant differences in heart rate at any of the 4 measured time points compared with baseline were noted for either group. The experimental group had a significantly higher incidence of complications, including tissue sloughing, when compared with the control group (p < .001). Participants in the control group reported significantly lower VAS scores than those in the experimental group. Both types of topical anesthetic showed similar impacts on alterations to heart rate. No benefits were seen with the use of 10% lidocaine, 10% prilocaine, and 4% tetracaine as a topical anesthetic prior to a maxillary infiltration of local anesthetic when compared with 20% benzocaine.