Er:YAG激光预备对牙釉质表面性能及树脂粘结强度的影响

目的:探讨Er:YAG激光预备对牙釉质表面性能及树脂粘结强度的影响。方法:选取50颗无龋坏、无充填物的人离体前磨牙或磨牙,用涡轮手机按近远中方向将离体牙切割成颊/舌两部分,最终选取84个样件,按不同的表面处理方法随机分为7组(A-G组),每组12个样件。每组2个样件扫描电镜观察,其余10个样件分别在处理后的牙釉质表面粘结光固化复合树脂,进行剪切强度测试。结果:A组剪切强度最高(20.51±3.33) MPa。B、C、D组剪切强度次之,与A组比差异无统计学意义。E、F、G组剪切强度较弱,其中E组剪切强度与B、C、D组无显著差异,F、G组与其他组有显著差异。扫描电镜观察:随着激光能量的增加,牙釉质表面粗糙度增加。激光处理后再进行酸蚀处理,牙釉质表面整体结构均匀,釉柱结构清晰可见,无玷污层。结论:Er:YAG激光处理牙釉质表面不能达到类似酸蚀的效果。激光加酸蚀能达到类似酸蚀的效果。牙釉质剪切粘结强度随着激光能量的增加而增加。关键词] Er:YAG激光 酸蚀 牙釉质 剪切粘结强度

Influence of Er:YAG Laser Treatment on Enamel Surface and Shear Bond Strength of Resin.

Objective: To investigate the influence of Er:YAG laser treatment on the characteristics of enamel surface and the bonding strength of resin. Methods: Fifty human premolars and molars without any caries and fillings were collected and eighty-four mesiodistal sections of the teeth were selected.The specimens were randomly divided into 7 groups(Group A-G) based on the different surface treatments (n=12).Two specimens in each group were randomly chosen and observed by scanning electron microscope (SEM). The other ten specimens in each group were bonded to the light-cured composite resin and the shear bond strength (SBS) were tested. Results: The highest SBS value of Group A was 20.51±3.33Mpa.The values of Group B,C and D were lower than that of Group A.However,the difference between these four groups was not statistically significant. The values of Group E,F and G were lower than those of other four groups.The differences between Group F and G and the other five groups were statistically significant. There was no significant difference between Group E and Group B,C and D. The SEM results showed that the surface roughness of enamel increased with the enhancement of laser energy.When the specimens were etched by acid after laser treatment process, the structure of enamel surface became uniform without smear layer and the structure of the enamel column was clearly visible. Conclusion: The Er:YAG erosion of enamel surface could not achieve a similar result as acid etching. The enamel surface treated by laser combined with etching could achieve similar effect with acid etching. The SBS results were increased with the increasing of laser energy.