Post-operative pain as a risk factor for reduced quality of life after root canal treatment: A prospective clinical study.

To evaluate the (i) incidence of post-operative pain after RCT at 24 h, 48 h and 7 days, (ii) factors affecting the incidence of post-operative pain and (iii) patients' post-operative quality of life (PoQoL) at 24 h, 48 h and 7 days. One hundred and sixty two (n = 162) patients underwent either single-visit or multiple-visit RCT or retreatment at the Restorative Department. Post-operative pain was assessed via phone calls at 24 h, 48 h and 7 days via the Numeric Rating Scale (NRS) and Modified Verbal Rating Scale (MVRS) pain assessment tools. The PoQoL was assessed at the same three time points based on an adopted questionnaire which assessed pain on chewing, speaking, sleeping, ability to perform daily activities and social relations as well as the effects of pain on the overall QoL. The incidence of pain and the effects on the PoQoL were evaluated using descriptive analysis while the prognostic factors were evaluated using ordinal logistic regression analysis. Patients who felt pain after instrumentation had mild (24 h n = 24, 48 h n = 23) to moderate pain (24 h n = 13, 48 h n = 13) that decreased after 7 days. Post-obturation discomfort was highest at 24 h (n = 41), reduced at 48 h (n = 31) and 7 days (n = 11).The majority of patients who felt pain after treatment needed analgesics only at 24 and 48 h for pain control. Post-instrumentation and post-obturation pain did not affect patients' overall PoQoL, although many complained of chewing difficulty within 24 to 48 h. Only pre-operative pain within 24 h before treatment was a positive predictive factor for post-instrumentation pain in the simple ordinal logistic regression model. As for the post-obturation pain, molar tooth was associated with 2.5 times higher likelihood of post-obturation pain. Post-operative pain after RCT was common within 24 to 48 h but reduced at 7 days, with a likelihood of chewing difficulty following treatment. The pain felt was mainly mild to moderate, well controlled by analgesics and did not significantly affect the PoQoL. Clinical Trial Registration: ClinicalTrials.gov ID NCT06412263, protocol ID 295316.