Saliva contamination effect on shear bond strength of ceramic brackets with an orthodontic hydrophilic resin

Abstract Introduction Some fator, such as the presence of saliva, are able to influence the adhesion of the bracket to the tooth enamel during the orthodontic bonding procedure and may cause the adhesive failure. Objective The aim of this study was to evaluate the shear strength of orthodontic ceramic brackets bonded with Transbond XT and Transbond Plus Color Change to bovine teeth, under saliva contamination and the adhesive failure mode. Material and method Sixty bovine permanent incisors were randomly divided into 4 groups (n=15) according to bonding material and saliva contamination: Group 1 (G1) bonded with Transbond XT with no saliva contamination; Group 2 (G2) bonded with Self Etching Primer and Transbond Plus Color Change with no saliva contamination; Group 3 (G3) bonded with Transbond XT with saliva contamination and Group 4 (G4) bonded with Transbond Plus Color Change with saliva contamination. Result The Kruskal-Wallis non-parametric test (p<0,05) was used and showed that G1 differed statistically from G2 and G3. There was no statistical difference between the other groups. The adhesive remnant index (ARI) ranged between 2 and 3 in G1 and between 0 and 1 score in the other groups. Conclusion Saliva contamination decreases the shear bond strength of ceramic brackets bonded with conventional Transbond XT hydrophobic resin. On the other hand, the Transbond Plus Color Change hydrophilic resin associated with a Self Etching Primer, under saliva contamination, provide a sufficient shear bond strength, suitable for their clinical use.

摘要
诸多因素可影响正畸粘接操作中托槽与牙釉质间的粘接强度，其中唾液的存在即为常见影响因素之一，甚至可引发粘接失败。
目的：本研究旨在评估唾液污染条件下，分别采用Transbond XT与Transbond Plus Color Change粘接剂粘接的正畸陶瓷托槽在牛牙上的剪切强度，并分析粘接破坏模式。
材料与方法：将60颗恒切牛牙按粘接材料及唾液污染情况随机分为4组（每组15颗）：G1组采用Transbond XT粘接且无唾液污染；G2组采用自酸蚀底涂剂联合Transbond Plus Color Change粘接且无唾液污染；G3组采用Transbond XT粘接且存在唾液污染；G4组采用Transbond Plus Color Change粘接且存在唾液污染。
结果：采用Kruskal-Wallis非参数检验（p<0.05）分析结果显示，G1组与G2、G3组间存在统计学差异，其余组间无显著统计学差异。G1组的粘接残留指数（Adhesive Remnant Index，ARI）评分介于2~3分，其余各组的ARI评分介于0~1分。
结论：唾液污染会降低采用传统疏水性Transbond XT粘接剂粘接的陶瓷托槽的剪切粘接强度；而联合使用自酸蚀底涂剂的亲水性Transbond Plus Color Change粘接剂，在唾液污染条件下仍可提供满足临床应用需求的剪切粘接强度。