Effect Of Electroacupuncture With Local Anesthesia On Pain And Stress During Impacted Lower Third Molar Surgery

Perioperative pain and stress during surgical extraction of impacted lower third molars remain clinically relevant despite the use of local anesthesia. Psychological factors such as dental anxiety and physiological stress responses contribute to variability in pain perception and perioperative outcomes. Electroacupuncture has been proposed as a non-pharmacological adjunct that may modulate both nociceptive and stress-related pathways through neurohumoral mechanisms, including endogenous opioid release and autonomic regulation.

This prospective randomized controlled trial is designed to evaluate the effect of electroacupuncture as an adjunct to local anesthesia on perioperative response in patients undergoing ambulatory surgical extraction of impacted lower third molars. The study incorporates a three-arm parallel design, including electroacupuncture, sham acupuncture, and standard care without acupuncture, allowing differentiation between specific and non-specific effects of the intervention.

An integrated assessment approach will be used to capture multiple dimensions of the perioperative response, including subjective, biological, and physiological components. This design enables a comprehensive evaluation of the interaction between stress, autonomic activation, and nociceptive processing in a standardized oral surgery model. The findings are expected to contribute to the understanding of the clinical value of electroacupuncture as an adjunctive modality in perioperative care.

• Electroacupuncture (Procedure): Electroacupuncture is applied for 15 minutes prior to local anesthesia using a standardized protocol with selected acupuncture points. Electrical stimulation is delivered via a digital electroacupuncture device at an individually adjusted intensity to produce a clear but non-painful sensation.
• Sham Acupuncture (Procedure): Sham acupuncture consists of superficial needle insertion at non-acupuncture points without electrical stimulation or needle manipulation. The procedure mimics the active intervention in duration and setting but is designed to have no therapeutic effect.

Primary outcomes

• Perioperative Pain Intensity [Baseline and 30 minutes after surgical extraction]: Perioperative pain intensity assessed using a Numeric Rating Scale (NRS 0-10), where 0 indicates no pain and 10 indicates the worst imaginable pain; higher scores represent a worse outcome.

Secondary outcomes

• Perceived Stress [Baseline and 30 minutes after surgical extraction]: Perceived stress assessed using a Numeric Rating Scale (NRS 0-10), where 0 indicates no stress and 10 indicates the highest perceived stress, and the 10-item Perceived Stress Scale (PSS-10); higher scores on both scales indicate greater perceived stress and a worse outcome.
• Salivary Cortisol Levels [Baseline and 30 minutes after surgical extraction]: Salivary cortisol concentrations measured as a biomarker of stress response using enzyme-linked immunosorbent assay (ELISA).
• Salivary Alpha-Amylase Levels [Baseline and 30 minutes after surgical extraction]: Salivary alpha-amylase concentrations measured as an indicator of sympathetic activity using enzyme-linked immunosorbent assay (ELISA).
• Salivary Substance P Levels [Baseline and 30 minutes after surgical extraction]: Salivary substance P concentrations measured using ELISA as a biomarker of nociceptive response.
• Systolic Blood Pressure [Baseline and immediately after surgical extraction]: Systolic arterial blood pressure measured noninvasively using a validated automated digital monitor as an indicator of autonomic response, reported in millimeters of mercury (mmHg).
• Diastolic Blood Pressure [Baseline and immediately after surgical extraction]: Diastolic arterial blood pressure measured noninvasively using a validated automated digital monitor as an indicator of autonomic response, reported in millimeters of mercury (mmHg).
• Heart Rate [Baseline and immediately after surgical extraction]: Heart rate measured using a validated automated digital monitor as an indicator of autonomic response, reported in beats per minute (bpm).

Sex: All, ages: 25 Years to 35 Years

Inclusion Criteria:

* Adults aged 25-35 years
* ASA physical status I-II
* Indication for ambulatory surgical extraction of an impacted lower third molar
* Ability to understand the study procedures and provide written informed consent
* Willingness to comply with study procedures, including saliva sampling protocol
* Ability to abstain from food, beverages, and oral hygiene procedures for at least 1 hour prior to saliva sampling

Exclusion Criteria:

* Pregnancy
* Epilepsy
* Presence of a pacemaker or other active electronic implant
* Coagulation disorders
* Active infection at the site of acupuncture
* Systemic inflammatory diseases
* Oral inflammatory conditions (e.g., gingivitis or periodontitis)
* Hyposalivation
* Chronic opioid use
* Psychiatric conditions that may affect pain or stress assessment
* Use of nonsteroidal anti-inflammatory drugs, corticosteroids, or antibiotics within 7 days prior to the procedure
* Menstruation at the time of saliva sampling
* Inability or unwillingness to comply with study procedures

• Jasminka Peršec, Associate Professor, PhD, Study chair, University Hospital Dubrava