连续波热牙胶充填后不同时机桩腔预备对根尖封闭性的影响

目的 评价连续波热牙胶充填后不同时机桩腔预备对根尖封闭性的影响。方法 50颗单根管牙,采用冠向下法,使用ProTaper机用镍钛系统预备根管。随机选择5颗牙为阴性对照组,5颗牙为阳性对照组。另40颗牙随机分为A、B、C、D4组,每组10颗,所有根管均使用连续波热牙胶充填术充填根管,阳性对照组不使用根管封闭剂,然后A、B、C、D组分别于根充后即刻、3d、7d、30d四个不同时间点进行桩腔预备。采用葡萄糖定量法测定第2、7、14、21、28d从冠方向根方渗漏的葡萄糖量。结果 从第14d起即刻桩腔预备组与延迟桩腔预备三组相比,葡萄糖渗漏量均有显著性差异(P<0.05),而实验期间延迟桩腔预备三组之间相比没有统计学差异(P>0.05)。结论 延迟桩腔预备会削弱充填材料和封闭剂封闭根管的能力。

Coronal leakage along root fillings of continuous wave of condensation technique after post space preparation at different moments

Objective To study the effects of post space preparation on the sealing ability of filling materials at different moments Methods 50 single root canal teeth were prepared using crown-down technique with ProTaper Nickel-titanium root canal preparation system.These teeth were divided randomly into A,B,C,D four experimental groups of 10 samples each and two control groups.Control groups included 5 positive controls and 5 negative controls.The experimental groups and negative controls were filled with continuous wave of condensation technique and Cortisomol sealer respectively,but positive controls were only filled with continuous wave of condensation technique.Then all these teeth were prepared for post space at different moments.The concentration of glucose leakage was determined at 2,7,14,21,28 days by using a glucose penetration model.Results From the 14th day,the glucose leakage of the immediate post space preparation group was significantly lower than those of the delayed post space preparation groups（P〈0.05）,and the difference among delayed post space preparation groups was not significant throughout the experiment（P〉0.05）.Conclusions The sealing ability of filling materials and Cortisomol sealer was decreased after delayed post space preparation.