2%氯己定预处理牙本质对全酸蚀粘接剂的微拉伸强度的影响

Effect of Pretreatment Dentin with 2% Chlorine on Microtensile Tensile Strength of Fully Acidified Dentin Adhesive

目的探讨2%氯己定(CHX)预处理牙本质对全酸蚀粘接剂的粘接强度的影响。方法取40颗离体人磨牙,磨除牙合面牙釉质至釉牙本质界下,暴露牙本质,作为粘接面。随机分为四组,取两组在酸蚀后涂粘接剂前涂布CHX为实验组,另外两组同法涂布蒸馏水处理为对照组。所有组经全酸蚀粘接剂3M ESPE Single Bond2处理后,堆积超声树脂制备成粘接模型。取一组实验组和一组对照组制备成标准试件后,直接测试微拉伸粘接强度;另外一组实验组和空白组在冷热循环5 000次后制备标准试件,并测试其微拉伸粘接强度。运用体视显微镜和扫描电镜观察断裂界面,分析断裂模式。结果 CHX处理组和空白组之间的微拉伸强度的差异具有统计学意义(P<0.05)。老化后,CHX处理组和空白组之间的微拉伸强度的差异也具有统计学意义(P<0.05)。经CHX处理的即刻组和老化组,其差异具有显著性统计学意义(P<0.01)。空白对照的即刻组和老化组间无统计学差异(P>0.05)。所有组别的断裂大多是在粘接剂内部即界面断裂,少数的混合断裂及极少数的内聚断裂。结论 2%CHX预处理能够增强牙本质全酸蚀粘接强度,老化后增强作用变得更加明显。

Objective To investigate the effect of 2% chlorhexidine(CHX)pretreatment on the bond strength of one total-etch adhesive system. Methods Forty isolated human molars were selected,removed the enamel to enamel dentin boundary,and exposed dentin as the adhesive surface. All the teeth were randomly divided into 4 groups--2 groups were treated with CHX before the application of the adhesive,and the other two groups were treated with distilled water as the control groups. The dentin surface was then bonded with composite resin using a totaletching adhesive(Single Bond2,3 M ESPE),and deposited as a bond model. All the bond models were prepared into standard specimens for the micro tensile bond strength test. The microtensile bond strength of one experimental group and a blank group were tested immediately after bonding. The other specimens were tested after 5000 times thermocycling. The fracture mode was analyzed by stereomicroscope and electron microscope. Results The bond strengths of the CHX treated groups and blank groups were statistically different(P<0.05)before and after thermocycling. The difference was statistically significant(P<0.01)in CHX treated groups between immediate bond strength and aging bond strength. Conversely,there was no statistical difference between the immediate group and the aging group of the blank groups(P>0.05). Most of the fractures in all groups were interrupted at the interface,a few mixed fractures and a very small number of cohesive fractures. Conclusion The adhesive strength of untreated dentin did not change significantly after aging,and the bonding strength of dentin pretreated with CHX was obviously enhanced,and the enhancement was more obvious after aging.