Method: Twenty healthy consenting adult volunteers (male: 12, female: 8) participated in this study. This study was approved by IRB in our college. Each subject underwent five experiments in a randomized crossover manner. Adhesive tape for hemostasis (Medipatch®) was instilled with 0.06ml of one of each agent (2% lidocaine hydrochloride: L, 2% lidocaine hydrochloride with epinephrine 12.5µg/ml: LE, 20% ethyl amino benzoate: B, physiologic saline: C) or cotton ball was applied with 20% benzocaine 0.06g (20% ethyl amino benzoate: Bz). Adhesive tape or cotton ball was attached to transitional region of dried alveolobuccal sulcus at upper right canine for two or five minutes. Then, 33 or 30 gauge needle was inserted to a depth of 2mm and held for 10 seconds. Insertion pain was evaluated using a visual analog scale (VAS) and a pain rating scale (PRS: “Neither pain nor sense of pressure”, “Sense of pressure”, “Slight pain”, “Severe pain”) immediately after the needle was removed. For statistical comparisons, Effectiveness was evaluated by analgesia rate (percentage of subjects who had “Neither pain nor sense of pressure” and “Sense of pressure” in total subjects). Friedman's X2r-test and Wilcoxon t-test with Bonferroni correction were used. A p values less than 0.05 was considered significant.
Result: VAS was lower and analgesia rate was higher at 33G than at 30G in all groups, and also in L and LE groups than in C, B and Bz groups.
Conclusion: L and LE showed stronger effects than B, Bz and C, though no difference was observed between L and LE. The results indicate that topical anesthesia using an adhesive tape and 2% lidocaine solution may be better than conventional one.