Er:YAG激光对牙本质超微结构作用的电镜观察

激光照射牙本质被认为是一种改善粘接效果的新方法。此研究的目的是采用电镜观察Er:YAG激光照射后牙本质的超微结构，评价激光处理牙本质以改善牙体组织和修复体之间粘接性能的可行性。共8颗新鲜拔除的人上颌第三磨牙按照牙合贴面的要求进行牙体预备，拔除牙齿进行牙体预备后接受激光照射，采用电镜观察牙本质的超微结构。分为两组，4颗牙齿为对照组，4颗牙齿为实验组。牙体预备后，对实验组牙齿的牙本质进行Er:YAG激光照射。采用电镜观察牙本质小管，熔融和裂隙等情况。对于实验组，观察结果未见玷污层，牙本质小管清晰。同时，对照组可以见到牙本质小管内有明显的玷污层，因此牙本质小管不清晰。该研究提示Er:YAG激光照射牙本质可以清除牙本质小管内的玷污层，这可能会提高牙体组织和修复体之间的粘接性能。

Effect of Er:YAG laser on ultrastructure of dentin by scanning electron microscopy

Laser treatment on dentin has been considered a new method to bring better adhesive effect.The purpose of this study was to observe the ultrastructure of dentin after the treatment of Er:YAG laser by scanning electron microscopy(SEM)and to assess the possibility of laser treatment on dentin to improve the adhesive properties between tooth and restoration. A total of 8 freshly extracted sound human maxillary third molars were prepared according to occlusal veneer. Extracted teeth were treated by Er:YAG laser after tooth preparation. The ultrastructure of dentin was observed by SEM. They were divided into 2 groups, 4 for the control group and 4 for the experimental group. After tooth preparation, the dentin of the experimental group was treated by Er:YAG laser. The specimen were observed by SEM including dentinal tubules, melting and fissure etc. It was observed that in the experiment group there was no smear layer, and the dentinal tubule was clear. Meanwhile, in the control group, there was obvious smear layer in the dentinal tubule therefore the dentinal tubule was not clear. This study suggests that Er:YAG laser treatment on dentin after tooth preparation can remove smear layer in the dentinal tubules, which may improve the adhesive properties between tooth and restoration.