Clinical Outcomes and Salivary C-Reactive Protein Levels Following Mandibular Third Molar Surgery with Cold Saline Irrigation: A Randomized Split-Mouth Clinical Trial

To evaluate the effect of low-temperature saline irrigation on postoperative clinical outcomes and salivary C-reactive protein (sCRP) levels after surgical removal of impacted mandibular third molars. This randomized, controlled, split-mouth clinical trial was conducted in 14 patients. The experimental side received saline irrigation at 0 to 4°C, whereas the control side received irrigation at room temperature (∼25°C). Postoperative pain, facial swelling, and trismus were assessed on postoperative days 1, 2, and 7. Unstimulated saliva was collected preoperatively and at 48 hours postoperatively for sCRP quantification. Between-side comparisons were performed using paired t-tests or Wilcoxon signed-rank tests as appropriate. Changes in sCRP (T2–T0) were analyzed within and between sides. The effect size for Wilcoxon tests was calculated as r = Z/√N. Pain on postoperative day 1 was significantly lower on the low-temperature irrigation side than on the control side (p = 0.021). No significant between-side differences were observed for pain on days 2 and 7, or for facial swelling and trismus at any follow-up time point. sCRP levels increased significantly at 48 hours postoperatively on both sides (p = 0.001). However, the increase in sCRP was smaller on the low-temperature irrigation side compared with the control side (p = 0.048). Low-temperature saline irrigation may reduce early postoperative pain and attenuate the postoperative increase in sCRP, but did not demonstrate a beneficial effect on facial swelling or trismus in this study. ClinicalTrials.gov, NCT07243210.