低温等离子体用于牙齿外漂白后对牙釉质粘接强度的影响

目的：观察牙釉质经低温等离子体处理后，与树脂的即刻粘接强度及粘接界面的超微形态。方法：选取牛切牙，沿唇舌向纵剖为两半，制备釉质粘接样本，随机分为4组（每组样本n=20），（1）1组：酸蚀+树脂粘接（对照组）；（2）2组：诊室外漂白+即刻酸蚀+树脂粘接；（3）3组：等离子体处理5 min+即刻酸蚀+树脂粘接；（4）4组：等离子体处理5 min+树脂粘接，粘接样本均使用single bond 2粘接系统及Filtek Z250树脂。万能试验机测试剪切粘接强度，扫描电镜观察处理及酸蚀后釉质表面的超微形态，以及断裂界面,SPSS17.0软件包进行单因素方差分析及多个样本均数间的两两比较。结果：剪切强度测试显示：4组(8.60 MPa)低于其余各组，差异有统计学意义(P<0.05)；2组(17.89 MPa)高于4组，但低于其余两组，差异均有统计学意义(P< 0.05)，而1组(34.82 MPa)和3组(34.69 MPa)间差异无统计学意义（P＞0.05）。扫描电镜显示等离子体处理5 min后，釉质表面呈现轻微熔融状较规则的外观形态，但不如酸蚀处理后的釉质表面的蚀刻形态明显。1组和3组粘接后断裂界面相似，均为混合断裂。结论：与常规诊室漂白相比，应用等离子体处理釉质表面后即刻进行酸蚀与树脂粘接，粘接强度不受影响。

Bonding strength of resin and tooth enamel after teeth bleaching with cold plasma

Objective:To investigate the immediate bond strength and surface structure of resin and the tooth enamel which treated by cold plasma.Methods:In the study,40 bovine incisors were divided into two equal parts.In this sense,all enamel adhesive samples were prepared and then randomly divided into 4 groups(n =20).group 1:acid +single bond 2 +resin composite(control group);group 2:beyond bleaching+acid+single bond 2+resin composite;group 3:treated by cold plasma for 5 minutes+acid+single bond 2+resin composite;group 4:treated by cold plasma for 5 minutes+single bond 2+resin composite.Single bond 2 bonding system and Filtek Z250 resin were used in this experiment.The shear bond strength was tested by universal testing machine.The surface of the enamel in different processes was observed by scanning electron microscope (SEM).Statistical analyses by the single factor analysis of variance and multiple pairwise comparisons were performed with SPSS 1 7 .0 .Results:The shear bond strength of group 4 (8.60 MPa)was significantly lower than that of the other three groups (P<0.05). The shear bond strength of group 2 (1 7.89 MPa)was higher than that of group 4,but lower than group 1 and group 3 (P<0.05).There was no significant difference between group 1 (34.82 MPa)and group 3 (34.69 MPa).Scanning electron microscope indicated that the enamel treated by cold plasma had slight molten form,which was different from etched enamel surface.The fractured surface of group 3 was mix fracture,which was similar to the control group (group 1 ).Conclusion:Compared with the conven-tional clinic bleaching,immediate bond strength of resin-enamel that treated by cold plasma has not been affected.