The micro effusion was measured in 10 stained teeth of each group. The micro-chink between filling materials and the wall of root canal of the other 10 teeth was measured with scanning electron microscope.

• 三天后随机选每组10颗牙经染色后行微渗漏长度测量，另外每组10颗牙经扫描电镜测量根管壁与牙胶间微缝隙宽度，进行统计学分析。