自酸蚀粘接流动树脂初始应用层厚度对牙本质粘接强度的影响

Effect of base layer thickness of a self-adhesive resin on dentin bonding strength

目的研究自酸蚀粘接流动树脂（DvadFlow，DF）初始应用层厚度对牙本质粘接性能的影响。方法选取离体人磨牙20颗，制备牙本质试件，将牙本质试件分为4组。G0．5、G1．0、G2．0直接使用DF，初始应用层厚度分别为0．5、1．0和2．0mm；GOB配合使用OptiBond All in One（OB）自酸蚀粘接剂后再使用DF，初始应用层厚度为2．0mm。4组上部均充填复合树脂，然后制备截面积为1mm×1mm的条形试样并测定微拉伸粘接强度，每组试样均为15个。扫描电镜观察4组牙本质-树脂界面的形态及断裂类型。结果GOB、G0．5、G1．0及G2．0组微拉伸粘接强度依次减小，分别为（20．19±3．11）、（8．65±1．58）、（6．65±1．13）及（5．70±0．60）MPa，4组间总体比较及两两比较差异均有统计学意义（P〈0．05）。G0．5、G1．0、G2．0及GOB组粘接断裂类型为混合破坏B2型（DF自酸蚀粘树脂与牙本质混合破坏）的样本比例分别为14／15、13／15、14／15及13／15。结论直接使用DF自酸蚀粘接流动树脂，其与牙本质的粘接强度随材料初始应用层厚度增加而降低。

Objective To evaluate the effect of base layer thickness of DyadFlow（DF） self-adhesive resin on dentin bonding strength. Methods Twenty extracted intact human molars were randomly selected and the occlusal surface of each molar was prepared by removing the enamel and exposing the dentin surface. The prepared molars were divided, randomly and equally, into 4 groups. For groups G0.5, G1.0 and G2.0, DF was applied directly on the dentin surfaces following the manufacturer＇s instruction, and for group GOB, OptiBond All-in-One（OB） self etching adhesive was applied on the dentin surface before using DF. The base layer thickness of DF was 0.5 mm, 1.0 ram, 2.0 mm, 2.0 mm for groups G0.5, G1.0, G2.0 and GOB, respectively. Composite crown were built up on each tooth, then the samples were sectioned longitudinally into sticks with proximately 1.0 mm2 bonding area（for microtensile bond strength[MTBS] testing） or slabs （for bonding interface observation with SEM）. Fifteen sticks were obtained for each group. The fracture surface was also observed using SEM and the fracture type of each specimen was determined. Results The MTBS were： GOB （20.19± 3.11） MPa 〉G0.5 （8.65±1.58） MPa〉G1.0 （6.65±1.13） MPa 〉G2.0 （5.70±0.60） MPa（P〈0.05）. Bonding interface fracture B2 was most frequently observed for all groups： G0.5： 14/15, G1.0： 13/15, G2.0：14/15 and GOB： 13/15. Conclusions The MTBS decreased when the base layer thickness of DF increased. Direct application of DF self-adhesive resin on dentin surface adhesive restorations should be concerned.