不同树脂粘接剂对纤维桩粘接强度及断裂界面的作用

摘要

BACKGROUND:The good performance of resin cements used to cement fiber-posts has been confirmed, but the adhesive properties of different kinds of resin cements remain different. OBJECTIVE:To compare the shear bond strength of three resin cements (Bisco One-step, Clearfil DC, 3M ESPE RelyX Unicem) used to cement fiber posts and to observe their adhesive properties. METHODS:Fifteen extracted teeth were selected and the crowns were removed with a diamond bur 1-mm coronal to the cemento-enamel junction fol owed by endodontic treatment. Then the teeth were randomly divided into three groups (n=5). Glass fiber posts were cemented respectively with three resin cements, and after embedding, the roots were cut into 2-mm-thick sections for push-out tests. The mean shear bonding strengths were compared, and the failure modes were recorded and analyzed under a high-power microscope. RESULTS AND CONCLUSION:Mean bonding strengths were (4.69±1.85) MPa for Bisco One-step group, Clearfil DC, (6.10±0.36) MPa for Clearfil DC group, and (7.04±0.92) MPa for 3M ESPE RelyX Unicem group. The bonding strengths of RelyX Unicem and Clearfil DC groups were significantly greater than that of Bisco One-step group (P<0.05), but no significant difference was between 3M ESPE RelyX Unicem group and Clearfil DC group. Al samples were mainly defined as modes Ⅱ andⅣfailure, indicating that the adhesive failure was the most mode of fracture. These findings showed that the bonding strengths of fiber posts cemented to root canals with three different resin cements system exhibit significant differences, and the interface between dentine and resin cements is the primary weak link.%背景：树脂类粘接剂粘接纤维桩的良好性能已被肯定，但不同种类树脂粘接剂的粘接性能不同。　　目的：比较Bisco One-step、Clearfil DC及3M RelyX Unicem三种树脂粘接系统对纤维桩的剪切粘接强度，研究纤维桩与根管壁牙本质间的粘接性能。　　方法：将15颗人离体牙在釉牙骨质界冠方1 mm处与牙体长轴方向垂直去除牙冠，磨平，常规热牙胶技术根管治疗后，随机分为3组，分别采用Bisco One-step、Clearfil DC及3M RelyX Unicem树脂粘接剂将玻璃纤维桩黏固于根管内，包埋后分别切片制备2 mm厚的样本，采用微推出法测试各组样本的粘接剪切强度；在高倍显微镜下观察所有被测样本的破坏类型。　　结果与结论：Bisco One-step粘接剂组、Clearfil DC粘接剂组及3M RelyX Unicem粘接剂组的粘接强度分别为(4.69±1.85)，(6.10±0.36)，(7.04±0.92) MPa，Bisco One-step粘接剂组粘接强度与Clearfil DC粘接剂组、3M RelyX Unicem粘接剂组比较差异有显著性意义(P <0.05)，Clearfil DC粘接剂组粘接强度与3M RelyX Unicem粘接剂组比较差异无显著性意义。所有样本均主要为Ⅱ，Ⅳ型破坏，即脱出的桩表面完全被粘接剂覆盖或根管壁及桩表面均有部分粘接剂覆盖。表明3种粘接系统对纤维桩粘接强度差异显著，根管壁牙本质-粘接树脂界面是粘接薄弱环节。