目的 探讨3种脱敏剂对牙本质粘结剂粘结强度和微观形态的影响.方法 12颗完整无龋的人第三磨牙,去除咬合面釉质,随机分为4组(n=3):A组(空白)、B组(Oravive)、C组(GC 护牙素)、D组(氟化钠甘油).A组不做处理,B、C、D组分别使用相应脱敏剂在牙本质表面处理,全部样本Prime&Bond NT树脂粘结剂粘结,复合树脂修复厚约4~5 mm,慢速切割机制成1.0 mm×1.0 mm×8.0 mm长方体试样,微拉伸测试仪测试粘结强度并进行统计学分析.体视显微镜下观察断裂模式,每组随机选取3个断裂前样本扫描电镜观察.结果 粘结强度A组最高[(24.45±4.57) Mpa],与其它三组有统计学差异(P<0.01),B、C、D三组间无统计学差异(P>0.05);断裂模式多为粘结剂断裂的混合破坏,各组断裂模式间无统计学差异(P>0.05);扫描电镜观察A组混合层薄而致密,树脂突长而粗,其余三组混合层不均一,树脂突短而细.结论 3种脱敏剂可显著降低牙本质全酸蚀粘结剂的粘结强度.%Objective To evaluale the effects of three desensitizers on bond slrength of adhesive syslem and invesligale the bond in lerface by scanning electron microscope( SEM). Methods Twelve inlacl and non-carious human third molars were divided randomly into four groups with 3 teeth in each group. The occlusal enamel was removed and treated. Group A was served as control group,and the other three groups were treated with Oravive, Tooth Mousse and 75％ NaF glycerin respectively. Then all the specimens were bonded with Prime&Bond NT adhesive. A block of composite resin was builded up to 4 ～5 mm on each tooth,which was sectioned occluso-gin givally to obtain bar-shaped specimens(1. 0 mm × 1.0 mm × 8 mm) for the microtensile bond strength and bonding failure modes were observed under stereomicroscope. The mean value of bond strength was analyzed by one-way ANOVA test. Three samples were chosen randomly from each group for SEM investigation. Results The μTBS of control group was significant higher than other three groups (P ＜ 0. 01) , but there were no significant differences among group B、C、D(P＞0. 05). The failure modes of most specimens were cohesive fracture within adhesive system and there were no significant differences ( P ＞0. 05). The hybrid zone of the control group was uniform as well as resin tags were longer,better than other three groups. Conclusions All the three desensitizers could decrease the microten sile bond strength with Prime&Bond NT adhesive system.
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