Objective:To estmate the apex blocking efficacy of five kinds of root canal blocking materials and analyze the influence factors.Methods: The root canals of 100 fresh extracted incisor teeth were filled with calcium hydroxide paste,chloroform gutta percha paste,self made root canal blocking agent,AH 26 and AH-plus respectively in lateral or vertical pressure way.Their microeffusion was measured after stained.Results:Apex microeffusion filled with calcium hydroxide is higher than the others,and the o...