【作者】 于霞；

【导师】 方厂云；

【作者基本信息】 中南大学 ， 口腔临床医学， 2009， 硕士

【摘要】 目的:采用微拉伸强度测试法检测复合树脂-牙本质粘接界面的微拉伸强度,以及扫描电镜下观察微拉伸试件断裂后的断面图像,比较和评价Prime&Bond NT,XenoⅢ,XenoⅤ三种粘接剂不同涂布时间对牙本质的粘接效果的影响,为临床应用提供实验依据。方法:选择60颗因正畸需要、新鲜拔除的、健康的年轻恒前磨牙,沿牙体长轴在牙合面正中将牙齿切割成两部分,完全磨除牙釉质,抛光牙本质表面。分为3个组,即NT组,ⅩⅢ组,ⅩⅤ组。根据粘接剂不同涂布时间,每组再随机分为4个亚组,即10sec组,20sec组(标准组),30sec组和40sec组。除粘接剂涂布时间外,其余操作步骤均按照厂商使用说明进行树脂堆塑。上述试件贮存于37℃生理盐水24h,制备成沙漏状,粘接面积控制在1 mm~2左右,然后测试其微拉伸强度。取微拉伸断裂后的试件,将断面的牙本质区干燥,喷金,扫描电子显微镜下观察其微观形态。结果:Prime&Bond NT涂布10sec组的微拉伸强度值明显低于20sec组、30sec组与40sec组(P＜0.05),后三组的微拉伸强度均值间无统计学差异(P＞0.05);XenoⅢ和XenoⅤ的检测结果具有一致性,两者的20sec组与30sec组间微拉伸强度值无统计学差异(P＞0.05),但均明显高于10s组(P＜0.05),而40s组的微拉伸强度均值反而有所下降(P＜0.05)。扫描电镜下观察发现,3种粘结剂的20see组和30see组牙本质小管口的封闭情况都比10sec组好;XenoⅢ组,XenoⅤ组中20sec组和30sec组均比Prime&Bond NT组20sec组和30sec组的牙本质小管口封闭情况要好;XenoⅢ和XenoⅤ的40sec组中,牙本质断面均出现坑状结构,树脂突明显减少;Prime&Bond NT的40see组与其20sec组及30sec组相比较,其牙本质小管封闭性差别不大。结论:1.全酸蚀粘接剂Prime&Bond NT的涂布时间达到20秒即可获得理想的粘接强度,延长涂布时间对提高粘接强度无明显意义。2.自酸蚀粘接剂XenoⅢ,XenoⅤ涂布时间至少应达20秒才能获得较满意的粘接强度,延长涂布时间对提高粘接强度不但无益,而且当其超过40秒时会导致粘接强度降低。3.Prime&Bond NT涂布时间20秒以上、XenoⅢ,XenoⅤ涂布时间在20～30秒范围内均可获得较好的牙本质小管封闭效果;相比较而言,XenoⅢ,XenoⅤ比Prime&Bond NT的牙本质小管封闭性更好。更多还原

【Abstract】 Objective The purpose of this study was to evaluate the microtensile bond strengths of 3 dentin adhesive systems (Prime & Bond NT, Xeno III, Xeno V) at different application times (10, 20, 30, 40 seconds), and to observe the microstructure characteristic of the dentin-adhesive resin fracture interface under SEM.Methods 60 intact and fresh premolars extracted from orthodontic patients aged 14-21 years old were employed. Put every tooth into two parts along the long axis in the maxillofacial median, completely wore away the enamel, and polished the dentin surface. And then the prepared teeth were randomly divided into three classes (NT, X III and XV). Every class in accordance with adhesive coating time were randomly assigned to four groups with 10 specimens each, that is, 10sec group, 20sec group (standard group), 30sec and 40sec group. Composite build-ups were constructed incrementally according to the use of instructions. After physiological saline storage at 37℃for 24 h, teeth were sectioned to obtain sticks with cross-sectional areas of 1.0 mm~2 to be tested in tension (0.5 mm/min) immediately, then to observe the fracture interface of the dentin-adhesive resin under SEM. The microtensile bond strength (uTBS) values were analyzed by two way repeated measures ANOVA and SNK test (a = 0.05).Results uTBS was significantly lesser with the 10-second application time than with the 20-second, 30-second and 40-second time for Prime&Bond NT. There was no significant difference among the later three. The ruselts were similar for Xeno III and Xeno V, There was no significant difference between 20-second and 30-second application time ,but they had significantly higher mean uTBS value than 10-second. The 40sec group’s bonding strength decreased compared with 20sec or 30sec group (P <0.05).Observing the fracture interface of the dentin-adhesive resin under SEM, we found that in Prime & Bond NT, Xeno III and Xeno V classes, the occluding situation of the dentinal tubules of 20sec and 30sec groups are better than 10s group. The occluding situation of the dentinal tubules of 20sec and 30sec groups in Xeno III and Xeno V classes are better than that in Prime & Bond NT class respectively. In Xeno III and Xeno V classes the pit-like structure after the dissolving of smear layer caused by etching agent appeared on the dentin fracture of the 40sec group. But the same phenomenon can’t be found in 40sec group of Prime & Bond NT class.Conclusions1. In Total-etching adhesives Prime & Bond NT case, the desired dentin bonding strength can be achieved when the application time spent reaches to 20 sec. The extension of time has no significance on bonding strength.2. In Self-etching adhesives Xeno III and Xeno V cases, the desired dentin bonding strength can be achieved when the application time spent is no less than 20 sec. The extension of time may takes in negative impact instead of positive effect.3. In order to obtain a wonderful occluding situation of the dentinal tubules, 20sec is the limit application time of Prime&Bond NT while 20～30sec is the proper application time of Xeno III and Xeno V. In addition, it’s presented that occluding situation of the dentinal tubules is greater in Self-etching adhesives Xeno III and Xeno V cases, compared with that in Total-etching adhesives Prime & Bond NT case.更多还原