The experiment root canals were filling with RF, HA and VITAPEX respectively, while the other twelve root canals were filling ZOE as control. Apical microleakage was determined using dye infiltration and measured by microscope.

• 分别充填ZOE、RF、HA、VITAPEX 4种材料至距根尖孔0.；5mm处，用染料渗入法在显微镜下观测染料渗入距离。