纳米根管充填材料根尖封闭能力的实验研究

目的 观察纳米材料根充后根尖微渗漏请况，评价其根尖封闭能力。方法 30颗离体单根管牙牙根，随机分为三组，每组10个，预备完成的根管用牙胶尖和一种根管糊荆、采用侧方加压法进行充填。根据染料在牙根中的渗入深度，评价根尖微渗漏情况。结果 三种材料的根尖微渗漏有显著差异（P〈0．01）；n-ZO组的根尖微渗漏最小，n-HA组次之，ZOE组最大。结论 纳米氧化锌糊剂和纳米羟磷灰石糊剂具有良好的根尖封闭性，可以作为根管封闭剞用于根管充填。

Assessment of apical sealing of nanomaterials

Objective To examine the apical sealing ability of two nanomaterial as root canal sealers.Methods Thirty roots of single-rooted teeth were prepared using step-back technique and randomly and equally divided into three groups.The root canals were obturated with gutta-percha and sealed with zinc oxide-eugenol sealer(ZOE,served as the control group),nano-zinc-oxide sealer(n-ZO),and nanohydroxyapatite sealer(n-HA),respectively.The filled roots were stained with ink,decalcified and dehydrated,and then placed in methysalicylate to make them transparent.The linear dye penetration was assessed using a stereomicroscope under X16 magnification.The apical sealing of the sealers was assessed according to the length of dye penetration.Results The distance of dye penetration of n-ZO was the smallest among the three sealers,while the distance of dye penetration of n-HA was smaller than that of ZOE.Conclusion Nano-zinc-oxide and nanohydroxyapatite have favorable apical sealing ability and are suitable as root canal sealers.