Er,Cr:YSGG激光联合粘结剂封闭牙本质小管的封闭效果

目的 通过扫描电镜观察,定量评估并比较自酸蚀粘结剂、Er,Cr:YSGG激光及其联合应用对牙本质小管的封闭效果.方法 将40颗人新鲜拔除的第三磨牙制备成1.5 mm厚的牙本质片,用35%磷酸处理10 s,采用简单随机分组法将标本随机分为四组:A组为空白对照组,不做任何处理;B组和C组为自酸蚀粘结剂组和Er,Cr:YSGG激光组,分别用Clearfil S3 Bond自酸蚀粘结剂和Er,Cr:YSGG激光进行表面处理;D组为Er,Cr:YSGG激光联合粘结剂组,先用Er,Cr:YSGG激光进行表面照射,后用自酸蚀粘结剂进行表面处理,扫描电镜下观察各组牙本质表面及纵剖面的超微结构.结果 (1)表面结构:A组牙本质小管口全部开放,清晰无玷污层;B组牙本质小管口表面覆盖大量晶体状结晶物,牙本质小管口明显缩窄;C组牙本质小管口表面呈凹凸不平的熔融状,牙本质小管口不规则地向管中心缩窄;D基本看不到牙本质小管口,牙本质表面覆盖有一层均匀的细结晶物.(2)纵剖面结构:A组牙本质小管呈条索状平行排列,小管内光滑无堵塞物;B组牙本质小管内可见长条状的致密树脂突堵塞物;C组牙本质小管内堵塞物进入牙本质小管深度较浅;D组牙本质小管内可见白色细条索状堵塞物,外部为一层均匀致密物质.(3)组间牙本质小管直径和面积比较,空白对照组>粘结剂组>激光组>联合组,组间牙本质小管堵塞率比较,联合组>激光组>粘结剂组,差异均有统计学意义(P<0.05).结论 自酸蚀粘结剂,Er,Cr:YSGG激光,以及两者联合应用均能有效封闭牙本质小管,且联合组优于单独应用.

Occluding effects of the combined application of Er,Cr:YSGG laser and adhesive on dentinal tubules:an in vitro study.

Objective To quantitatively evaluate and compare the sealing effects of self-etching adhe-sive, Er, Cr: YSGG laser and the combined application on dentin tubules by scanning electron microscope (SEM). Methods Forty fresh extracting human third molar samples were made into dentin specimens of 1.5 mm thickness that were treated with 35%phosphoric acid for 10 seconds. The specimens were randomly divided into four groups by simple random distribution method. Group A served as the control group without any further treatment;group B was treated with Clearfil S3 Bond self-etching adhesive alone; groups C were irradiated with Er, Cr:YSGG laser;groups D were treated with Er, Cr:YSGG laser plus Clearfil S3 Bond self-etching adhesive. The surface was irradiated and subjected to surface treatment with a self-etching binder. The utrastructure of dentin surface and vertical section in different groups was observed by SEM. Results (1) Surface observation:In group A, all of the dentinal tubules were numerous exposed without smear layer. In group B, the dentin tubules orifices were covered with irregular crystalline substance and the aperture of dentin tubule significantly narrowed. In group C, dentin tubule surface had a melted appear-ance and the dentin tubule orifices irregularly narrowed to the pipe center. In group D, dentin tubule orifices can hardly be seen and the surface structure primarily showed a smooth crystalline substance appearance. (2) vertical section obser-vation:In group A, the dentin tubules were arranged in parallel without blockage. In group B, the tubules were covered with long strips of dense resin clogs. In group C, the tubules were covered with blockages not deep as group B. In group D, the dentin tubules were covered with white thin dense funicular clogs, and outside is a layer of uniform density materi-al. (3) In terms of diameters and areas of open dentinal tubules, there was significant difference between groups, group A>group B>group C>group D (P<0.05). In terms of plugging rate of open dentinal tubules, group D>group C>group B (P<0.05). Conclusion All self-etching adhesive, Er, Cr:YSGG laser and the combined application can occlude the tu-bules effectively, and moreover, the combined application has an advantage over Er, Cr:YSGG laser, while the Er, Cr:YSGG laser is superior to self-etching adhesive.