Papers of the Week

Acupuncture is a complementary and nonpharmacological intervention that can be effective for the management of chronic pain in addition to or instead of medication. Various animal models for neuropathic pain, inflammatory pain, cancer-related pain, and visceral pain already exist in acupuncture research. We used a newly validated human pain model and examined whether acupuncture can influence experimentally induced dental pain. For this study, we compared the impact of manual acupuncture (real acupuncture), manual stimulation of a needle inserted at non-acupuncture points (sham acupuncture) and no acupuncture on experimentally induced dental pain in thirty-five healthy men who were randomized to different sequences of all three interventions in a within-subject design. BORG CR10 pain ratings and autonomic responses (electrodermal activity and heart rate variability) were investigated. An initial mixed model with repeated measures included preintervention pain ratings and the trial sequence as covariates. The results showed that acupuncture was effective in reducing pain intensity when compared to no acupuncture (β =-0.708, p = 0.002), corresponding to a medium Cohen's d effect size of 0.56. The comparison to the sham acupuncture revealed no statistically significant difference. No differences in autonomic responses between real and sham acupuncture were found during the intervention procedures. Perspective: This study established a dental pain model for acupuncture research and provided evidence that experimentally induced dental pain can be influenced by either real acupuncture or manual stimulation of needles at non-acupuncture points. The data do not support that acupoint specificity is a significant factor in reducing experimental pain. Trial registration: The study was registered at clinicaltrials.gov (registration ID: NCT02589418).