0099-2399/85/1103-0135/$02.00/0 JOURNAL OF ENDODONTICS Copyright 9 1985 by The American Association of Endodontists Printed in U.S.A. VOL. 11, NO. 3, MARCH 1985 CLINICAL ARTICLE Incidence of Postoperative Pain Following the Use of Different Sealers in Immediate Root Canal Filling Incidencia del Dolor Postoperatorio Luego de la Obturacion del Conducto Radicular en Una Sola Sesion Realizada Con Distintos Materiales Tayfun Ala~am, DDS, PhD Whether to instrument and obturate an endodontically involved tooth in single or in multiple visits is a subject of disagreement among both practitioners and investi- gators. Filling the canal in one sitting is a time-reducing procedure for both clinician and patient. However, pos- sible complications such as postoperative pain and swelling raise some objections to this procedure. Ferranti (1) compared postoperative symptoms fol- lowing single-and multiple-visit endodontic therapy. He found that 48.6% of the patients had slight tenderness while 7.3% experienced intense pain in the 109 cases completed in a single visit. Fox et al. (2) evaluated 247 teeth following complete endodontic treatment in one visit. Within 24 h after the treatment, 90% of the patients had little or no sponta- neous pain. O'Keefe (3), in his study on pain in endodontic ther- apy, found no significant difference in the total post- operative pain response after one- or two-visit endo- dontic therapy. Soltanoff (4) reported that 19% of the cases he completed in one visit had moderate to severe pain while only 14% of the cases experienced the same degree of pain after multiple visit root canal therapy. This result was statistically significant. Ashkenaz (5) reported a 4% incidence of postoper- ative pain in 195 vital teeth that were treated in a single visit. In Pekruhn's study (6), 15.6% of the patients that were treated in either single or multiple visits reported a relatively painful response on the first postobturation :lay. The single-visit patients seemed to experience a greater degree of postobturation pain than the multiple- 135 visit patients. However, the difference was not statisti- cally significant. Oliet (7) conducted a clinical study to compare single- visit endodontic procedures. The single-visit patients had moderate to severe pain in 10.6% of the cases. However, the amount of postoperative pain experi- enced by the single- and two-visit patients was not significant. Finally, Roane et al. (8) investigated the incidence of postoperative pain after single- and multiple-visit en- dodontic procedures. They found that the frequency of pain was lower in the single-visit group (15.2% of treatments) when compared with the multiple-visit group (31.2% of treatments) and pointed out the need for further studies to explain various aspects of one- visit endodontic treatment. Realizing the need for more specific investigations, the present study was conducted to correlate the post- operative pain present after single-visit endodontic ther- apy of vital teeth with the type of root canal sealer utilized in the obturation. MATERIALS AND METHODS The study involved 212 vital single or multirooted teeth which required endodontic therapy as a result of a diagnosis of irreversible pulpitis. All of the teeth were treated by the same operator. Each canal was instru- mented to the radiographic apex utilizing 3% hydrogen peroxide as the irrigant, dried, and filled with laterally condensed gutta-percha cones. However, four different root canal sealers were used. Iodoform paste was used in 53 cases, Oxpara root canal cement (R. R. Co.) was