Mechanisms of Acupuncture Analgesia on Experimental Dental Pain - A Psychophysical Study (Phase1)

Mechanisms of Acupuncture Analgesia on Experimental Dental Pain - A Randomized, Single Blinded, Sham-controlled Psychophysical Study (Phase1)

The investigators will assess the effects of manual acupuncture on experimental dental pain in 36 healthy subjects by means of subjective pain intensity ratings and pain-specific autonomic nervous system (ANS) reactions.

This psychophysical and -physiological study is the first part of a two-phase project which pursues to explore how acupuncture-induced pain modulation interacts with pain-specific brain processing patterns by means of functional magnetic resonance imaging (fMRI) and by using an experimental dental pain model.

In this preceding study, the characterization of manual acupuncture effects on the experimental dental pain model will be tested under laboratory conditions and without restrictions of an fMRI-measurement in order to provide a sound foundation for the following fMRI-experiment. Pain modulating effects of the manual acupuncture intervention (4 points: needle manipulation of bilateral large-intestine 4 (LI4), stomach 6 and 7 (ST6, ST7) ipsilateral to the stimulated tooth) will be compared to sham-acupuncture (insertion and manipulation of 4 non-acupuncture points) and a control intervention (no acupuncture) which will each be performed at 3 different days in a randomized order. Intervention effects on experimental dental pain will be assessed by testing of 36 healthy volunteers by means of subjective pain intensity ratings and pain-specific ANS reactions such as electrodermal activity and heart rate/respiratory changes. Besides laying the groundwork for the following fMRI experiment, this study could provide valuable basic insights into the dynamics of the tested manual acupuncture effects and further provide important knowledge for the planning of future clinical studies encompassing dental conditions and development of acupuncture treatments.

Inclusion Criteria:

• right-handed
• Written informed consent
• Fluent in German language
• Sufficient dental sensitivity for the tooth stimulation
• No acupuncture treatment in the previous 12 months
• No medical knowledge about acupuncure

Exclusion Criteria:

• Alcohol, drug, and analgesics consumption within the last 24 hours
• Complaints of diseases of the oral cavity
• Pre-existing neurological and(or psychiatric conditions
• History of severe dental pain
• Regular intake of pain medication
• History of brain injuries
• Alcohol and drug abuse
• Chronic diseases that require a permanent intake of drugs