Objective: Initial orthograde root canal therapy (RCT) is common. Persistent pain is a known outcome, but its frequency is unknown. Therefore, we report on the proportion of patients experiencing pain and describe their perception of the cause.
Method: 62 dentists within the National Dental Practice-Based Research Network (NationalDentalPBRN.org) enrolled consecutive patients requiring RCT. Data were collected by questionnaire 6 months following obturation. Persistent pain criteria included the report of tooth-related pain with an average intensity =1/10 on a numeric rating scale over a recall period of 1 month and =1 day of pain over that month. Additional questions regarding medication use and perceived cause for the pain were asked. Result: 708 patients were enrolled over a 6-month period and follow-up data were collected from 651 (92%). Sixty-five (10%) patients met criteria for persistent pain. Mean (S.D.) average pain intensity for these patients was 2.7/10 (1.8), ranging in intensity from 1 to 9/10 with 2 patients reporting severe pain (=7/10) and 15 moderate (4-6/10). In comparison, patients not meeting criteria reported <0.01/10 (0.1), ranging from 1 to 2/10. Average number of days in pain for those meeting criteria was 10.7 (13.2), ranging from 1 to 30/30 with 15 reporting 20 or more days in pain. 33 (51%) of these patients meeting criteria reported taking medications for this pain in the last month, as opposed to 3 (0.7%) patients not meeting the pain criteria (p<0.001). Of the 19 patients who answered the question related to perceived cause, 7 identified “dental treatment”, 3 “dental disease”, 1 “trauma”, and 8 did not have an opinion. Conclusion: Six months following initial RCT, 1-in-10 patients were experiencing pain that was mostly mild in intensity. One third of patients answering the question about perceived cause felt it was resultant from dental treatment.