2Direnzo A, Gresla T, Johnson BR. Postoperative pain after 1-and 2-visit root canal therapy. Oral Surg Oral Med OralPathol Oral Radiol Endod,2002,93(5) :605-610.
3Albashaireh ZSM, Alnegrish AS. Postobttrration pain after single and nultiple-visit endodonfic therapy. A prospective therapy. J Dent, 1998,26 ( 3 ) : 227 -232.
4Glennon JP, Ng YL, Setehell D J, et al. Prevalence of and factors affecting postpreparation pain in patients undergoing two-visit root canal treatment. Int Endod J, 2004,37( 1 ) :29-37.