(PR45) Clinical and Biological Predictors of Persistent Postoperative Pain in Apicoectomy Patients – a Prospective Cohort Study

Abstract: It has been shown that pain can persist after routine dental procedures, including apicoectomy. However, clinical and biological factors contributing to persistence of pain are not understood. In the present study, we assessed whether pre-operative pain, post-operative pain and its resolution trajectory, clinical testing, cytokine levels obtained from gingival crevicular fluid (GCF) and genetic factors predicted pain at 1 month. 93 subjects participated in the study. Pre-operative pain, endodontic testing and pre-op and 1 week post-op GCF were collected. Pain levels were reported during the post-operative 7-day period and out to 6 months after surgery. Cytokine levels were quantified in GCF samples. We performed univariate data analysis followed by logistic regression analysis. Our initial results demonstrate that 26% of subjects reported pain one month after surgery. Patients who report pain at 1-month had more days in pain within the last week (3.6 days vs 1.1 days), more frequent palpation hypersensitivity (42% vs 15%), higher initial pain intensity (3.9 vs 2.5). In logistic regression analysis, pre-operative pain predicted pain at 1-month (OR: 7.03, p=0.024). Pre-op inflammatory and anti-inflammatory cytokines have elevated expression in surgical teeth compared to control teeth (TNF⍺; p=0.02, IL-1β; p=0.06). As we complete our analysis, we will determine if distinct subgroups have similar trajectories of pain resolution, differences in cytokine expression in GCF, genetic variation or gene expression among these groups. These results will ultimately be pivotal in the design of future risk-factor and intervention studies aimed at decreasing the burden of persistent post-surgical pain in dental patients.