Comparative Efficacy of Topical Anesthetics for Placement of Orthodontic Anchors

Placement of intraosseous orthodontic temporary anchorage devices requires no flap and may use topical, rather than injectable, local anesthetic. Objectives: The present study was designed to evaluate the efficacy of a traditional topical anesthetic (HurriCaine Topical Anesthetic Gel, 20% benzocaine, Beutlich Pharmaceuticals, B) compared with that of a newer combination one (TAC Alternate Topical Anesthetic Gel, 20% lidocaine, 4% tetracaine, 2% phenylephrine, Professional Arts Pharmacy, T) in preventing discomfort during placement of self-tapping anchorage devices (Quattro Orthodontic Anchorage System, GAC International, Inc.), utilizing both subjective (VAS) and physiologic (pulse rate change) parameters. Methods: In a double-blind, crossover trial, 17 adolescent and adult subjects were randomly assigned to receive one of the two topical anesthetics for pain control just prior to anchor placement. Subjects completed a Heft-Parker VAS before and immediately after anchor placement, and post-operative pulse rate was continuously monitored for 30 mins using a pulse oximeter.

Following a 5-day washout period, a second, contralateral anchor was placed using the comparator drug and the same protocol. Pre- and post-operative VAS scores and the maximum increases in post-operative pulse rates were compared statistically, as were the overall success rates for the study drugs. Results: Mean post-operative VAS scores in the T group were significantly lower than those in the B group (33.1 vs. 92.7, p<.05, paired sample t-test), and the success rates significantly higher in the T than the B group (100% vs. 29%, p<.01, Chi-square). Pulse rate changes did not differ significantly between the two experimental groups, and increased an average of 14% (9.9 BPM) in the T group and 14% (10.3 BPM) in B. Conclusion:

This study indicates that a combination topical anesthetic incorporating a vasoconstrictor is more efficacious that a single agent for controlling discomfort associated with orthdontic anchor placmement.