Methods:To observe the gaps between material and the walls of canals by scanning electron microscope ,the apical sealing ability of material by dye penetration method.

• 方法:采用染料渗漏法和扫描电镜观察新型聚氨酯液体根充材料与根管壁之间的密合度及其对根尖孔的封闭能力。