Er:YAG激光活化荡洗对桩道牙本质微观结构及纤维桩粘接强度的影响

Effects of Er: YAG laser-activated irrigation on the microstructure and bonding strength of the dentine in post space

目的 探讨铒:钇铝石榴石(Er:YAG)激光活化荡洗对桩道牙本质表面微观结构及纤维桩粘接强度的影响。方法 收集完整无龋裂纹因正畸拔除的下颌第一前磨牙40颗,根管治疗后在釉牙骨质界处截冠,余留残根,并均分为采用常规注射器冲洗(A组)和Er:YAG激光活化荡洗(B组)两组。两组残根桩道经不同方法冲洗清洁后,每组随机选取4颗(8个样本),采用扫描电镜观察清洁效果。根据粘接剂酸蚀模式不同,将每组剩余的16颗样本随机均分为两个亚组,每个亚组8颗。其中,A1、B1组采用全酸蚀模式进行粘接操作,A2、B2组采用自酸蚀模式进行粘接操作。每颗残根行纤维桩粘接后均自根颈到根尖区依次切割制取6个1 mm厚薄片样本,切取的试件薄片行推出实验及断裂模式观察。结果 扫描电镜结果显示,B组残根桩道牙本质表面清洁效果优于A组。A1、A2、B1、B2组总体纤维桩剪切粘接强度依次增高(P<0.05)。A1、A2组样本断裂模式以树脂水门汀-牙本质界面破坏为主,B1、B2组样本断裂模式以混合破坏为主。结论 Er:YAG激光活化荡洗预处理桩道牙本质的清洁效果较好,与自酸蚀粘接剂配合使用可提高纤维桩的粘接强度。

Objective To investigate the effects of Er: YAG laser-activated irrigation on the microstructure and bonding strength of the dentine in post space.Methods A total of 40 mandibular first premolars were collected, which were completely free of caries and cracks and were extracted due to orthodontic treatment. The residual roots were randomly divided into two groups of A and B,which were irrigated respectively by conventional syringe and Er: YAG laser activation. After post space irrigation procedures, the cleaning effect of 8 residual roots(4 premolars) selected from each group was observed by scanning electron microscope. According to different etching patterns of the adhesive, the remaining 16 samples in each group were randomly divided into two subgroups of A1,B1 and A2, B2, with 8 samples each. For the bonding operation, the full acid etching mode was used in the groups of A1 and B1 and the self-etching mode was used in the groups of A2 and B2. After each residual root was bonded with fiber post, 6 pieces of 1 mm thick specimens were cut from the root neck to the root apex in turn, which were used to push-out experiment and fracture mode observation.Results Scanning electron microscope results showed that the cleaning effect of the post dentin surface of residual roots in group B was better than that in group A. The overall shear bond strength of fiber posts was increased in an order of group B2 > group B1 > group A2 > group A1(P<0.05). The fracture mode of samples in groups of A1 and A2 was mainly the failure of resin cement-dentin interface, and the fracture mode of samples in groups of B1 and B2 was dominated by mixed failure.Conclusion Er: YAG laser-activated irrigation method has better effectiveness in cleaning the dentin surface of the post space and the bonding strength of fiber post can be improved by combined use of Er: YAG laser-activated irrigation self-etched bonding adhesive.