Britto Fernanda Alves Rodrigues, Lucato Adriana Simoni, Valdrighi Heloisa Cristina, Vedovello Sílvia Amélia Scudeler
Centro Universitário Hermínio Ometto, Araras, São Paulo, Brazil.
Department of Orthodontics, Centro Universitário Hermínio Ometto, Araras, São Paulo, Brazil.
Dental Press J Orthod. 2015 Mar-Apr;20(2):49-54. doi: 10.1590/2176-9451.20.2.049-054.oar.
The objective of this study was to assess, in vitro, the influence of bleaching gel and the use of desensitizing agent over bond strength of ceramic brackets bonded to bovine enamel.
One hundred bovine incisors were selected and randomly divided into five groups (n = 20): Group 1, control group (without bleaching); Group 2, bleached with 35% hydrogen peroxide; Group 3, bleached with 35% hydrogen peroxide (three applications, 15 minutes each) and desensitizing agent applied for 10 minutes; Group 4, bleached with 35% hydrogen peroxide for 40 minutes; Group 5, bleached with 35% hydrogen peroxide for 40 minutes with desensitizing agent applied for 10 minutes. Brackets were bonded 7 days after bleaching and submitted to shear bond strength test after 24 hours at a compression rate of 1 mm/minute. After fracture, the adhesive remnant index (ARI) was assessed under stereoscopic at 40 x magnification. Shear strength data (MPa) were submitted to one-way ANOVA and Tukey's test with significance level set at 5%.
Group 5 (29.33 MPa) showed significantly higher bond strength than Group 1 (19.19 MPa), Group 2 (20.59 MPa) and Group 4 (23.25 MPa), but with no difference in comparison to Group 3. There was no significant difference among the other groups. The adhesive remnant index showed predominance of score 3, that is, all resin remained adhered to enamel for all groups.
Bleaching with 35% hydrogen peroxide with calcium associated with desensitizing agent application produced higher bond strength values of brackets bonded to bovine enamel.
本研究的目的是在体外评估漂白凝胶和使用脱敏剂对粘结在牛牙釉质上的陶瓷托槽粘结强度的影响。
选取100颗牛切牙，随机分为五组（n = 20）：第1组为对照组（未漂白）；第2组用35%过氧化氢漂白；第3组用35%过氧化氢漂白（三次，每次15分钟），并使用脱敏剂10分钟；第4组用35%过氧化氢漂白40分钟；第5组用35%过氧化氢漂白40分钟，并使用脱敏剂10分钟。漂白7天后粘结托槽，24小时后以1毫米/分钟的压缩速率进行剪切粘结强度测试。断裂后，在40倍放大率的立体显微镜下评估粘结剂残留指数（ARI）。剪切强度数据（MPa）采用单因素方差分析和Tukey检验，显著性水平设定为5%。
第5组（29.33 MPa）的粘结强度显著高于第1组（19.19 MPa）、第2组（20.59 MPa）和第4组（23.25 MPa），但与第3组相比无差异。其他组之间无显著差异。粘结剂残留指数显示主要为3分，即所有组的所有树脂均仍粘结在牙釉质上。
35%过氧化氢联合钙并使用脱敏剂进行漂白可使粘结在牛牙釉质上的托槽获得更高的粘结强度值。
