Can Acupuncture Reduce the Induction Time of a Local Anaesthetic? - a Pilot Study

We report on a pilot study we undertook to investigate if segmental acupuncture treatment, given two minutes prior to a regional inferior dental block (ID) with Prilocaine Hydrochloride, would reduce the onset time of a local anaesthetic.

Thirty healthy people, who needed a regional inferior dental block (ID) as part of dental treatment in the lower jaw, were randomly allocated to three groups. They received segmental acupuncture, heterosegmental superficial acupuncture, or standard treatment (regional inferior dental block) without acupuncture. In the segmental acupuncture group, acupuncture was given within the innervation of the trigeminal nerve. The needles were left in for two minutes, followed by a regional inferior dental block (ID). In the second group, acupuncture needles were inserted superficially in extra-segmental points and left in for two minutes without stimulation, followed by the regional inferior dental block. A control group received standard treatment only, of a regional inferior dental block.

The concept ‘pain free for dental work’ was defined as ‘patients reporting pins and needles in the lower lip’ and measured by a drilling test. Patients who reported no pain during the drilling test were included in the study. The time from administration of the injection to the patients’ reporting pins and needles was recorded by an independent dental nurse.

All tested patients reported sufficient anaesthesia during the drilling test. In the segmental acupuncture group, anaesthesia was achieved after 62 seconds, compared to the heterosegmental superficial acupuncture group, who took 115 seconds and the control group, who received standard treatment only, and took 119 seconds. The difference between the segmental acupuncture group and the heterosegmental superficial acupuncture group was statistically significant (p<0.015); the difference between the segmental acupuncture group and the control, who received a regional inferior dental block only, was also significant (p<0.032). No significant difference was found between the heterosegmental superficial acupuncture group and the control group who received a regional inferior dental block only (p<0.84).

It appears from this pilot study that the onset time of local anaesthesia is reduced if segmentally administered acupuncture is given prior to the regional inferior dental block. However, it needs to be reproduced including objective measurements.