Predicting pre- and postoperative pain of endodontic origin in a southern Brazilian subpopulation: an electronic database study.

AIM To determine the prevalence of preoperative endodontic pain (PREP) and the incidence of postoperative endodontic pain (POEP), identifying the predictors of PREP and POEP in a southern Brazilian subpopulation, using clinical data from an electronic chart database (ECD). METHODOLOGY This retrospective observational study included 563 consecutive individuals presenting for root canal treatment (RCT). Patients were treated by undergraduate and graduate students, following standard RCT protocols. Demographic, medical and dental variables were extracted from a pre-structured and standardized ECD. The main outcomes PREP and incident POEP were collected through a 0-10 numeric rating scale, dichotomized as none/mild (<4) or moderate/severe (≥4) pain. Predictive models calculating the prevalence ratios (PR) of PREP and the relative risks (RR) of incident POEP were carried out with Poisson regression analysis, estimating the relationship between clinical factors, PREP and incident POEP. RESULTS Mean age at baseline was 49.2 ± 17.1 years, with 68.4% women. The prevalence and incidence of moderate/severe PREP and POEP were 44.4% and 3.8%, respectively. RCT intervention significantly reduced PREP (P < 0.001). Multivariate analysis revealed that group of teeth, location (mandibular teeth), pulpitis, necrotic pulp, preoperative swelling and periapical radiolucency were independently associated with moderate/severe PREP, whilst age ≥60 years and root canal retreatments were independent protective factors to PREP (P < 0.05). No demographic, medical or dental variables were associated with POEP, although molar teeth (RR = 4.23, 95%CI = 0.93-19.2, P = 0.056) had a borderline nonsignificant association. CONCLUSIONS Moderate/severe PREP was independently associated with age, group of teeth, location, preoperative swelling, retreatments and pulp and periapical status. No demographic, medical or dental variable predicted moderate/severe POEP following RCT amongst this subpopulation.