Leódido Gabriela da Rocha, Fernandes Hianna Oliveira, Tonetto Mateus Rodrigues, Presoto Cristina Dupim, Bandéca Matheus Coêlho, Firoozmand Leily Macedo
Department of Restorative Dentistry, Dental School, CEUMA - Maranhão University Center, São Luis, MA, Brazil.
Braz Dent J. 2012;23(6):698-702. doi: 10.1590/s0103-64402012000600012.
The aim of this in vitro study was to evaluate the shear bond strength of brackets after pre-treatment with different fluoride solutions. This study used 48 freshly extracted sound bovine incisors that were randomly assigned to 4 experimental groups (n=12). CG: (control) without treatment; NF: 4 min application of neutral fluoride; APF: application of 1.23% acidulated phosphate fluoride (APF) for 4 min; and SFV: application of 5% sodium fluoride varnish for 6 h. For each group, after surface treatment, prophylaxis of enamel and bracket bonding with Transbond XT composite resin (3M) were performed following the manufacturer's specifications. The shear bond strength was performed with a universal testing machine 24 h after fixing the brackets. The tooth surfaces were analyzed to verify the adhesive remnant index (ARI). Data were analyzed statistically by ANOVA and Tukey's test (α=0.05). There was statistically significant difference among the groups (p<0.0001). CG and NF groups presented significantly higher bond strength than APF and SFV. There was no significant difference between CG and NF or between APF and SFV (p>0.05). The analysis of ARI scores revealed that most failures occurred at the enamel-resin interface. It may be concluded that the pre-treatment of enamel with 1.23% APF and 5% SFV prior to fixing orthodontic brackets reduces shear bond strength values.
本体外研究的目的是评估不同氟溶液预处理后托槽的剪切粘结强度。本研究使用了48颗新鲜拔除的健康牛切牙，随机分为4个实验组（n = 12）。CG组：（对照组）未处理；NF组：应用中性氟4分钟；APF组：应用1.23%的酸蚀磷酸氟（APF）4分钟；SFV组：应用5%氟化钠清漆6小时。对于每组，表面处理后，按照制造商的规格，用Transbond XT复合树脂（3M）对釉质进行预防性处理并粘结托槽。在固定托槽24小时后，使用万能试验机进行剪切粘结强度测试。对牙齿表面进行分析以验证粘结剂残留指数（ARI）。数据采用方差分析和Tukey检验进行统计学分析（α = 0.05）。各组之间存在统计学显著差异（p < 0.0001）。CG组和NF组的粘结强度显著高于APF组和SFV组。CG组和NF组之间以及APF组和SFV组之间无显著差异（p > 0.05）。ARI评分分析显示，大多数失败发生在釉质-树脂界面。可以得出结论，在固定正畸托槽之前，用1.23%的APF和5%的SFV对釉质进行预处理会降低剪切粘结强度值。
