两种技术充填后根管桩腔预备后体外微渗漏研究

目的：研究桩腔预备对两种根管充填方法根管封闭效果的影响。方法：选择近期拔除的40颗单根管离体牙，采用逐步后退法机用扩管预备，随机分为A、B、C、D4组，配合AH—plus糊剂分别采用牙胶尖侧方加压（A、B组）及热牙胶垂直加压充填根管（C、D组），1周后对A、C组作桩腔预备，B、D两组作对照，印度墨水染色，对染料渗透的长度进行测量及分析。结果：B组和D组根尖微渗漏值无统计学差异，A组和B组、A组和C组、C组和D组的染料渗透长度有显著性差异（P〈0．01）。结论：桩腔预备降低了根尖封闭效果，热牙胶垂直加压充填对微渗漏的影响小于牙胶尖侧方加压充填。

Research on microleakage of two root canal obturators after post space preparation in vitro

Objective：To observe apical sealing ability on two root canal obturators after post space preparation. Method： Forty extracted human single-rooted human teeth were mechanically prepared using the step-back technique and then assigned to 4 experimental groups randomly of 10 teeth each,filled with lateral condensation technique or vertical condensation technique respectively.Post space preparation was done on 2 groups with different fillings after 7 days, another as negative controls. Apical microleakage was evaluated with ink dye penetration. Result： There were no statistically difference between negative controls （P 〉0.05）.More microleakage were detected after Post space preparation （P 〈0.01）. Conclusion： Post space preparation decreases apical sealing ability, and less microleakage were created when filled with Vertical condensation technique than with lateral condensation technique.