7Chong BS, Pitt-Ford TR. Enodontic retreament. Dent Update,1996,23(9) :384-7.
8Hulsmann M, Hahn W. Complications during root canal irrigation-literature review and case reports [J]. lnt Endod J, 2000, 33 (3): 186-193.
9Negm MM. Effect of intracanal use of nonsteroidal antiinflammatory agents on posttreatment endodontic pain [J] .Oral Surg Oral Med onal pathol, 1994,77 (4) : 507-511.
10Takcda FH, Harashima T, Kimura Y.A comparative study of the removal of Smear layer by three endodontic irrigants and two types of laser[J], lnt Endod,J, 1999, 32: 32-39.