The relationship of intracanal medicaments to postoperative pain in endodontics

AIM: To investigate the relationship of postoperative pain to three different medicaments placed in the root canal after a complete biomechanical debridement of the root canal system in patients presenting for emergency relief of pain. METHODOLOGY: Two hundred and twenty-three teeth belonging to 221 patients presenting as emergencies to the Royal Dental Hospital of Melbourne were included in the study. Inclusion was limited to patients with a diagnosis of pulp necrosis and acute apical periodontitis. All teeth underwent conventional root canal treatment, which involved the instrumentation to the apices of each canal at the first visit. Canals were instrumented using a stepback technique and hand-files along with irrigants using Milton's (1% sodium hypochlorite) solution followed by 15% EDTAC. The canals were dried and one of the following three medicaments was inserted into the canal in random sequence: Group 1: Ledermix paste (Lederle Pharmaceuticals, Division of Cyanamid, Wolfratshausen, Germany); Group 2: calcium hydroxide paste (Calcipulpe, Septodont, France); and Group 3: no dressing. Before dismissal, the preoperative pain experienced on the previous night was recorded using a visual analogue pain scale. Patients were then instructed to record the degree of pain experienced 4 h after treatment and daily for a further 4 days. RESULTS: The mean score pain for all three groups was between 42 and 48 prior to treatment being commenced. After 4 days, the pain score for Group 2 was 10, for Group 3 was 7 and for Group 1 was 4. Mean preoperative pain level was 44.4 (of a maximum 100) for all groups, and declined by 50% (to 22.1) after 24 h. Patients in Group 1 (Ledermix) experienced significantly less (P = 0.04) postoperative pain than those in the other two groups. There was no significant difference between Group 2 (calcium hydroxide) and Group 3 (no dressing). CONCLUSION: Under the conditions of this study, painful teeth with acute apical periodontitis that had been dressed with Ledermix paste gave rise to less pain than that experienced by patients who had a dressing of calcium hydroxide or no dressing at all. Ledermix is an effective intracanal medicament for the control of postoperative pain associated with acute apical periodontitis, with a rapid onset of pain reduction.