Hersh E V, Cooper S A, Segal H, Greene J
University of Pennsylvania School of Dental Medicine, Philadelphia.
J Clin Dent. 1993;4(2):52-4.
The purpose of this pilot investigation was to determine the usefulness of analgesic onset time as a measure of topical anesthetic efficacy in patients with spontaneous toothache pain. Under blinded conditions, 20 patients with spontaneous toothache pain from an open tooth cavity were randomly assigned to receive either 20% benzocaine or placebo (80% polyethylene glycol). The medication was applied directly to the open cavity in a volume of 3 drops. Patients then depressed a stop watch when they initially experienced pain relief. Patients who did not obtain relief were assigned the maximum onset value of 600 seconds. The average analgesic onset time was 111.8 seconds in the benzocaine group and 289.0 seconds in the placebo group. In the benzocaine group, 90% of the patients reported some pain relief, while a surprisingly high 60% reported some pain relief in the placebo group. The results of this study suggest that in the spontaneous toothache pain model, analgesic onset time is a valuable measure of topical anesthetic efficacy. In addition, polyethylene glycol at a concentration of 80% may not be a totally inactive vehicle.
这项初步研究的目的是确定镇痛起效时间作为衡量自发性牙痛患者局部麻醉效果的指标是否有用。在盲法条件下，将20名因开放性龋洞而患有自发性牙痛的患者随机分为两组，分别接受20%的苯佐卡因或安慰剂（80%聚乙二醇）。将药物以3滴的体积直接滴入开放性龋洞。患者在最初感到疼痛缓解时按下秒表。未获得缓解的患者被赋予600秒的最大起效值。苯佐卡因组的平均镇痛起效时间为111.8秒，安慰剂组为289.0秒。在苯佐卡因组中，90%的患者报告有一定程度的疼痛缓解，而在安慰剂组中，有高达60%的患者报告有一定程度的疼痛缓解，这一比例令人惊讶。本研究结果表明，在自发性牙痛模型中，镇痛起效时间是衡量局部麻醉效果的一个有价值的指标。此外，80%浓度的聚乙二醇可能并非完全无活性的载体。
