Salivary Cortisol Response After Ropivacaine-Dexamethasone Administration: A Randomized Clinical Trial

Background: This randomized parallel-group clinical study evaluated salivary cortisol as a biomarker of perioperative stress response during surgical extraction of impacted mandibular third molars performed under local anesthesia administration of ropivacaine and dexamethasone. Methods: The trial was registered in the ISRCTN registry (ISRCTN87752106). Ninety patients undergoing impacted mandibular third molar surgery were randomly assigned (1:1:1; n = 30/group) to receive inferior alveolar nerve block with 0.5% ropivacaine plus dexamethasone (R+D group), 0.5% ropivacaine (R group), or 0.5% bupivacaine (B group). Salivary cortisol as the primary outcome was measured at 15 min before anesthesia, and 15 min and 24 h postoperatively. Preoperative psychological stress was assessed using the Revised Norman Corah Dental Anxiety Scale. Results: No significant differences were observed between groups in preoperative anxiety (p = 0.890) or baseline salivary cortisol levels (p = 0.984). Significant intergroup differences in cortisol levels were observed at 15 min (p = 0.002) and 24 h postoperatively (p = 0.001). Cortisol levels at 15 min postoperatively were significantly lower in the R+D group compared to the R (p = 0.001) and B groups (p = 0.004) and after 24 h (R+D vs. R: p = 0.005; R+D vs. B: p < 0.001). Conclusions: The ropivacaine-dexamethasone administration significantly reduced perioperative salivary cortisol levels compared to ropivacaine alone or bupivacaine alone during impacted mandibular third molar surgery. This modulation of the neuroendocrine response likely results from dexamethasone-induced suppression of hypothalamic-pituitary-adrenal axis and the improved analgesic effects of this combination. The observed results may contribute to improved physiological stability, postoperative recovery and the clinical benefit of this anesthetic approach in oral surgery.