中文摘要：

目的评价4种根管充填方法的根充同质性和致密度，以期为临床应用提供参考。方法选择40颗单根管牙，镍钛旋转器械进行冠向下法根管预备，按随机数字表法分4组，分别采用热牙胶垂直加压充填法（A组）、固体核心载体充填法（B组）、常温流动牙胶充填法（C组）和冷牙胶侧压充填法（D组）进行根管充填，每组10颗牙。分别对每颗牙在4个水平进行片切，体式显微镜拍照，进行图像分析并计算牙胶充填面积百分比（percentage of gutta-percha filled area，PGFA），比较各组整体及根尖、根中、根冠区不同部分的根充同质性和致密度。结果根管整体水平A、B、C、D组PGFA值分别为（96．5±3．6）％、（95．6±3．9）％、（86．5±5．7）％、（81．5±4．2）％；根尖区各组PGFA值分别为（96．8±3．8）％、（97．2±4．0）％、（89．4±5．1）％、（79．84-3．4）％；根中区各组PGFA值分别为（95．6±4．0）％、（95．64-3．9）％、（83．4±5．3）％、（80．6±3．6）％；根管整体水平、根尖和根中区均显示A组和B组显著优于c组和D组（P〈0．01），D组显著低于其他各组（P〈0．01）；根冠区A组显著高于其他三组（P〈0．01），B组显著低于A组（P〈0．01），但显著高于C和D组（P〈0．01），C、D组之间差异无统计学意义（P〉0．05）。结论热牙胶垂直加压充填技术和固体核心载体充填技术在整体和根管各个部位均显示出较好的同质性和致密度；冷牙胶侧压组充填同质性和致密度欠佳。

英文摘要：

Objective To evaluate the homogeneity and density of root canal filling with four obturation techniques. Methods Forty extracted single root teeth were randomly divided into four groups with 10 teeth each. Under simulated clinical conditions, the root canals were shaped with Nickle titanium rotary files（Protaper） using crown-down technique and were filled with warm vertically condensed gutta- percha （ group A）, core carrier technique-thermafil （ group B）, guttaflow （ group C） and conventional cold laterally condensed gutta-percha （ group D）. Roots were sectioned at four levels . The cross-sections were photographed through a microscope, the photos were analysed, and the percentage of gutta-percha filled area （PGFA） was measured. Results The overall PGFA values were （96. 5 ± 3.6）%, （95.6 ± 3.9）%, （86.5±5.7）% and （81.5 ±4.2）% for groups A, B, C and D, respectively. The differences between these groups were statistically significant （ P 〈 0. 01 ）. Group A and B were significantly higher than group C and D （ P 〈 0. 01 ）. The PGFA in group D was significantly lower than that in other groups （ P 〈 0. 01 ）. The average PGFA in both group A and B was higher than that of group C and D at apical and middle level （P 〈0. 01 ）. Conclusions Warm vertical condensation and thermafil produce significantly higher PGFA than guttaflow and cold lateral condensation technique.