Acupuncture affects experimental dental pain

Acupoint specificity does not seem to be an important factor in reducing dental pain, a recent randomized cross-over trial has shown.

The study included 35 men (mean age, 23.7±4.1 years) who received one of three different interventions: real acupuncture, sham acupuncture, or no acupuncture. Dental pain was electrically induced using a validated pain model, through fabricated dental splints. The primary endpoint was pain intensity, measured using the Borg Category Ratio 10 (Borg CR10) scale.

Real acupuncture resulted in a significantly larger negative change in mean pain rating than the no acupuncture intervention (mean change, –0.67±1.35; p=0.002). On the other hand, Borg CR10 changes were comparable between the real and sham acupuncture conditions (mean change, –0.29±1.13; p=0.156).

Explorative analyses further showed that real acupuncture was significantly better than no acupuncture over all post-treatment time points (p<0.001). No such effect was found when compared to sham acupuncture (p=0.224).

Responses of the autonomic nervous system showed a similar pattern. Skin conductance level (SCL) was significantly more increased in the real vs no acupuncture group (p<0.001), though no such difference was reported in comparison to sham acupuncture (p=0.776). The same pattern was reported for SCL change values.

During the needle insertion phase, heart rate dropped significantly in the acupuncture as opposed to no acupuncture (p<0.001), but not to sham acupuncture (p=0.421). This remained true in the needle manipulation phase. Heart rate variability was also greater in the real vs no acupuncture, but not relative to sham acupuncture.

The present study “provided evidence that experimentally induced dental pain can be influenced by either real acupuncture or manual stimulation of needles at non-acupuncture points,” researchers said.