Davari A R, Yassaei S, Daneshkazemi A R, Yosefi M H
Department of Operative Dentistry, Faculty of Dentistry, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.
J Contemp Dent Pract. 2007 Jan 1;8(1):36-43.
A unique characteristic of some new bonding systems in operative dentistry is they combine conditioning and priming agents into a single acidic primer solution for simultaneous use on both enamel and dentin. Combining conditioning and priming into a single treatment step results in improvement in both time and cost-effectiveness to the clinician and, indirectly, to the patient. The purpose of this study was to determine the effects of the use of a self-etching primer on the bond strength of orthodontic brackets and on the bracket/adhesive failure mode.
Thirty-six fresh bovine incisors were collected and stored in a solution of 0.1% (weight/volume) thymol. The criteria for tooth selection included intact buccal enamel, no cracks caused by the presence of the extraction forceps, and no defects. The teeth were cleansed and polished with pumice and rubber prophylactic cups for ten seconds. Brackets were bonded to the teeth according to one of three protocols following the manufacturers' instructions--Group 1: Conventional multistep bonding system (control group) (n=12); Group 2: Self-etching primer system (n=12); and Group 3: Acid+self-etching primer system (n=12). Specimens were loaded to failure in a Zwick test machine (Zwick GmbH & Co, Ulm, Germany). Shear bond strengths were measured at a crosshead speed of 5 mm/min.
The mean shear bond strength in megapascals (Mpa) (standard deviation) were 11.7 (4.2), 10.5 (4.4), and 10.9 (4.8) for Groups 1, 2, and 3, respectively. The analysis of variance (ANOVA) was used to compare the three groups. The results indicated no significant difference in the bond strength between the three groups (P=0.800). The results of the Chi square test, evaluating the residual adhesives on the enamel surfaces, revealed no significant difference between the three groups (P=0.554).
Results of the present in vitro study indicate the use of self-etching primers may be an alternative to conventional phosphoric acid pre-treatment in orthodontic bonding.
口腔手术中一些新型粘结系统的一个独特特点是它们将酸蚀剂和底漆结合成一种单一的酸性底漆溶液，可同时用于牙釉质和牙本质。将酸蚀和底漆结合成一个单一的治疗步骤，对临床医生而言，在时间和成本效益方面均有所改善，并且间接对患者也是如此。本研究的目的是确定使用自酸蚀底漆对正畸托槽粘结强度以及托槽/粘合剂失效模式的影响。
收集三十六颗新鲜牛切牙，并保存在0.1%（重量/体积）百里酚溶液中。选择牙齿的标准包括颊侧牙釉质完整、不存在由拔牙钳导致的裂缝且无缺陷。用浮石和橡胶预防杯清洁并抛光牙齿十秒钟。按照制造商的说明，根据三种方案之一将托槽粘结到牙齿上——第1组：传统多步骤粘结系统（对照组）（n = 12）；第2组：自酸蚀底漆系统（n = 12）；第3组：酸 + 自酸蚀底漆系统（n = 12）。在Zwick试验机（德国乌尔姆的Zwick GmbH & Co公司）上加载样本直至破坏。以5毫米/分钟的十字头速度测量剪切粘结强度。
第1、2和3组的平均剪切粘结强度以兆帕（Mpa）（标准差）表示分别为11.7（4.2）、10.5（4.4）和10.9（4.8）。使用方差分析（ANOVA）比较三组。结果表明三组之间的粘结强度无显著差异（P = 0.800）。评估牙釉质表面残留粘合剂的卡方检验结果显示三组之间无显著差异（P = 0.554）。
本体外研究结果表明，在正畸粘结中使用自酸蚀底漆可能是传统磷酸预处理的一种替代方法。
