2Harrison JW, Baumgartner JC. Svec TA. Incidence of pain as-sociate with ehinical factors daring and after root canal therapy [J]. J Endod , 1983.9(9):384-387.
3Albashaireh Z, Alnegrish A. Postobturation pain after single- and multiple- visit endodontie therapy. A prospective study[J]. J Dent , 1998, 26(3): 227.
4Trope M, Delano Q, Orstavik D. Endodontic treatment of teeth with apical periodontitis: Single vs. multivisit treatment [J]. JEndod , 1999, 25(5): 345.
5Seltzer S. Endodontology [M]. 2nd ed. philadephia= Iea&Febiger , 1988:389-438.
6Tanomaru J M, Leonardo MR, Tanomaru Filho M, et al . Effect of different irrigation solutions and calcium hydroxide on bacte rim I.PS[J]. Int Endod J ,2003,36(11):733-739.
