纳米材料根管封闭剂根尖封闭性能的实验研究

In vitro evaluation of apical sealing ability of nanomaterial

目的:观察纳米材料的根尖封闭性能。方法:选取40个直根管的上前牙,随机分为4个试验组(每组各8个)和2个对照组(对照1组和对照2组各4个),采用逐步后退法预备根管,用侧向加压法进行充填。4个试验组所用根管封闭剂分别为氧化锌丁香油糊剂组(ZOE),羟磷灰石糊剂组(HA),纳米氧化锌糊剂组(NZO),纳米羟磷灰石糊剂组(NHA),置于微渗漏模型,于第1、2、4、7、10、15、20、25、30天检测从冠方向根方漏出的葡萄糖量,根据葡萄糖微渗漏情况,评价根尖封闭性。结果:经葡萄糖氧化酶法检测,4组材料的葡萄糖渗漏量有显著性差异(F值=16523.5,P<0.0001),渗漏量由高至低为ZOE>HA>NHA>NZO组(P<0.0001)。且4组材料的渗漏量均随时间延长呈上升趋势。其中ZOE上升趋势最显著。结论:纳米氧化锌糊剂具有良好的根尖封闭性能,羟磷灰石糊剂和纳米羟磷灰石糊剂次之,氧化锌糊剂根尖封闭性能最差。

Objective：To observe apical sealing ability of two kinds of nanomaterial. Methods：40 straight human maxillary anterior teeth were randomly divided into four experimental groups of 8 samples each and two control groups of 4 samples each. The root canals were prepared using step-back technique and obturated with gutta-percha and one of the sealers by the lateral condensation technique. Group 1 ： Filled with zinc oxide-eugenol sealer and gut- ta-percha （ZOE） ; group 2 ： Filled with hydroxyapatite sealer and gutta-percha （HA） ; group 3 ： Filled with nano- zinc-oxide sealer and gutta-percha （NZO）; group 4： Filled with nanohydroxyapatite sealer and gutta-percha （NHA）. The teeth were placed into microleakage model. Glucose leakage from the coronal to apical was measured by the concentration of glucose in apical reservoir at 1, 2, 4, 7, 10, 15, 20, 25 and 30 days with GOD （glucose oxidase ） method. The apical sealing ability of the materials were assessed according to the concentration of glucose leakage. Results：The glucose leakage of four kinds of materials differed significantly （P 〈 0. 000 1 ）. The glucose leakage of ZOE was more than that of HA, NHA, NZO. The glucose leakage of NZO was the smallest. The leakage of four kinds of materials increased with time. Conclusion： Nano-zinc-oxide has excellent apical sealing ability, hydroxypatite and nanohydroxypatite have favorable apical sealing ability.