纳米羟基磷灰石封闭牙本质小管扫描电镜观察

Effect of nano-hydroxyapatite on dentinal tubule occlusion evaluated by scanning electron microscopy

目的 观察纳米羟基磷灰石对牙本质小管的封闭效果.方法 收集新鲜拔除的完整、无龋的第三磨牙,制备牙本质片,完全随机分为人工唾液对照组、纳米羟基磷灰石组、Gluma脱敏剂组,每组18片.分别采用人工唾液、纳米羟基磷灰石和Gluma脱敏剂处理7d,然后模仿日常刷牙方法用去离子水涂刷标本,持续7d后扫描电镜观察牙本质片横切面牙本质小管封闭效果和纵切面渗透深度.结果 与人工唾液对照组相比,横切面纳米羟基磷灰石堵塞部分牙本质小管口,堵塞物与管壁之间可见缝隙,Gluma脱敏剂在牙本质小管口表面形成封闭层,纵切面纳米羟基磷灰石粉体部分渗入到牙本质小管内,渗入深度深浅不一,Gluma脱敏剂未见渗入.结论 纳米羟基磷灰石可有效地封闭牙本质小管。

Objective To observe the effect of nano-hydroxyapatite （nHA） on dentinal tubule occlusion by scanning electron microscopy （SEM）.Methods The third molars extracted from healthy adults were collected and prepared into slices.The specimen were randomly divided into artificial saliva control group, nHA group and Gluma desensitizer group.After 7 days treatment by artificial saliva, nHA and Gluma desensitizer, the dentine discs were brushed by micro-applicator with deionized water for 2 minutes, twice a day for extra 7 days.Occlusion of dentinal tubules in dentin discs were observed by SEM and the penetrating depth were compared among groups.Results Compared with artificial saliva, nHA crystals partially occluded dentinal tubules and penetrated into the tubules;gluma desensitizer formed a sealing layer on partially dentin surface, but no dentin permeability was observed.Conclusion nHA can occlude the dentinal tubules effectively.