Prevalence of persistent pain after endodontic treatment and factors affecting its occurrence in cases with complete radiographic healing.

Aims To (i) determine the prevalence of persistent dento-alveolar pain following nonsurgical and/or surgical endodontic treatment conducted in a teaching dental hospital and (ii) identify the risk factors associated with persistent pain after apparently successful root canal treatment.Study design A total of 175 patients/teeth were reviewed 12-59 months following treatment. The patients were examined clinically and radiographically and a detailed pain history obtained. Multiple logistic regression analysis was used to investigate the association between potential risk factors and persistent pain after successful endodontic treatment.Results The prevalence of persistent pain after successful root canal treatment was 12% (21/175). Treatment success was determined by the absence of clinical and radiographic signs of dental disease. The factors that were significantly (P < 0.05) associated with persistent pain following endodontic treatment were: 'duration of preoperative pain' [odds ratio (OR) = 8.6], 'preoperative pain from the tooth' (OR = 7.8), 'preoperative tenderness to percussion' (OR = 7.8), 'previous chronic pain problems' (OR = 4.5), 'gender' (OR = 4.5) and 'history of painful treatment in the orofacial region' (OR = 3.8). 'Type of treatment received (surgical or nonsurgical treatment)' showed borderline significance at the 10% level.Conclusions The presence and duration of preoperative pain from the tooth site, lasting at least 3 months, a positive history of previous chronic pain experience or painful treatment in the orofacial region, and female gender were important risk factors associated with persistent pain after successful endodontic treatment.