Double-Blinded Randomized Controlled Study Investigating the Efficacy of Exparel (Liposomal Bupivacaine) for Postoperative Pain Relief in Mandibular Third Molar Extractions

Third molar extractions frequently result in significant postoperative pain for patients, sometimes requiring narcotics for pain management. With the increased awareness of the addictive properties of narcotics, the field of oral and maxillofacial surgery (OMS) has been making progress to address postoperative pain with other modalities. Recently, liposomal bupivacaine (Exparel) has received significant attention in medicine due to its ability to provide prolonged post-surgical local anesthesia. While there is a variety of studies exploring the efficacy of Exparel following surgeries throughout the body, the current literature supporting its use relating to OMS procedures remains limited. Most notably, previous studies have shown that Exparel can decrease opioid consumption following third molar extractions. However, the efficacy of Exparel in pain management in comparison to other local anesthetic agents remains unclear. Thus, we aim to evaluate the efficacy of Exparel on minimizing postoperative pain following third molar extractions compared to bupivacaine. An IRB-approved double-blinded randomized controlled trial recruited patients undergoing bilateral third molar extractions at the Herman Ostrow School of Dentistry of USC. The inclusion criteria included patients undergoing bilateral mandibular third molar extractions along with none or bilateral maxillary third molar extractions, while the exclusion criteria included severe hepatic disease, inability to complete the postoperative questionnaire, pregnancy, the use of analgesics within 3 days prior to the procedure, use of antibiotics within 30 days, and additional mandibular extractions. Each patient received a 3 mL infiltration of Exparel on 1 side of the mouth and a 3 mL infiltration of 0.5% bupivacaine with 1:200,000 epinephrine (standard bupivacaine) on the other. Our primary outcome was pain intensity based on a numerical pain scale, and secondary outcomes included NSAID/Acetaminophen use, narcotic use, and any adverse effects. The pain intensity scale was recorded by the patient each morning and evening for 4 days following surgery. Statistical analysis was done via a 2-sample t-test. Additional stratification will be applied based on confounding factors, such as surgical or non-surgical extraction, tooth sectioning, flap design, degree of impaction, and extraction duration. Of 12 patients, 10 met inclusion criteria and underwent a split-mouth bupivacaine and Exparel injection after bilateral mandibular third molar extractions. Over the course of 4 days postoperatively, the sides receiving Exparel on average displayed less or equal levels of pain at all recorded times when compared with the sides of the mouth receiving bupivacaine. We noted the biggest difference on the evenings of day 0 and 2, with a mean reduction in pain levels of 1.187 (SD = 2.66) and 0.6 (SD = 2.18) on the sides receiving Exparel. Based on preliminary analysis, we did not see a statistically significant difference in the pain levels between the 2 sites ( P > .05). Of the 10 analyzed patients, 6 required the use of ibuprofen and/or acetaminophen while none required the use of narcotics. Adverse effects reported include chills, fever, lightheadedness, constipation, and headaches. We found no significant statistical difference in the postoperative pain levels of patients receiving Exparel in comparison to standard bupivacaine after mandibular third molar extractions. However, there is a trend of decreased pain values on the Exparel side of the mouth that can be observed. Analysis of a larger sample size will increase the power of our study to help confirm our preliminary analysis and if there is a clinically significant difference. Table 1Postoperative Mean Pain Levels on Sides Receiving Exparel or Bupivacaine. Open table in a new tab Table 2Postoperative Cumulative Pain Levels on Sides Receiving Exparel or Bupivacaine. Open table in a new tab