Association Between Eye Color and Postoperative Pain in Female Patients With Symptomatic Irreversible Pulpitis in Mandibular Molars: A Prospective, Parallel-Group, Observational Study.

Background: Current evidence indicates that some phenotypic characteristics, such as eye or hair color, might be associated with the experience of pain. We, therefore, compared the anesthetic success rate of inferior alveolar nerve block (IANB) and postoperative pain scores between light eyes and dark eyes in female patients who experienced symptomatic irreversible pulpitis (SIP) in a mandibular molar. Methods: This prospective, parallel-group, observational study was registered with ClinicalTrials.gov (NCT06206304). A total of 110 adult female patients who experienced moderate or severe pain with SIP participated in this study. All patients received IANB with 4% articaine with 1:100.000 epinephrine. Endodontic access cavity preparation was initiated after confirmation of IANB. Pain during treatment was recorded by using a Visual Analog Scale. Anesthetic success was recorded as "none" or "mild" pain. Root canal treatment was performed, with standardized protocols. Postoperative pain scores were also recorded at 24, 48, and 72 h and 7 days after treatment. Statistical analyses of the data were performed using the independent t-test, repeated measures ANOVA test, and Pearson's chi-square test. The statistical significance level was set at 0.05. Results: No significant differences were found in the success rate of IANB and postoperative pain scores between light- and dark-eyed patients at any time point (p > 0.05). The success rate of IANB was 72.73% and 67.27% for light- and dark-eyed patients, respectively. Conclusion: Pain scores decreased significantly after RCT in both groups on all days (p < 0.05). No significant differences were found in the success rate of IANB and postop pain scores between light- and dark-eyed female patients who experienced SIP in a mandibular molar. Trial Registration: ClinicalTrials.gov identifier: NCT06206304.