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

Not Applicable

Completed

• Conditions: Experimental Dental Pain
• Interventions: Procedure: Acupuncture; Procedure: Sham-Acupuncture; Procedure: No Acupuncture

• Registration Number: NCT02589418
• Lead Sponsor: University of Zurich

Brief Summary

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.

Detailed Description

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.

Study Timeline

• Study Start: 2015-10
• Study First Submitted: 2015-10-23
• Study First Submitted QC: 2015-10-26
• Study First Posted: 2015-10-28
• Status Verified: 2016-03
• Primary Completion: 2016-03
• Study Completion: 2016-03
• Last Update Submitted: 2016-03-14
• Last Update Posted: 2016-03-15

Recruitment & Eligibility

• Status: COMPLETED
• Sex: Male
• Target Recruitment: 35

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

Read More

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

Read More

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: SINGLE_GROUP

Arm && Interventions

Group	Intervention	Description
Healthy subjects	No Acupuncture	All subjects participate at 3 experimental conditions (Acupuncture, Sham-Acupuncture and No Acupuncture) at 3 different days in a randomized order.
Healthy subjects	Sham-Acupuncture	All subjects participate at 3 experimental conditions (Acupuncture, Sham-Acupuncture and No Acupuncture) at 3 different days in a randomized order.
Healthy subjects	Acupuncture	All subjects participate at 3 experimental conditions (Acupuncture, Sham-Acupuncture and No Acupuncture) at 3 different days in a randomized order.

Primary Outcome Measures

Name	Time	Method
Comparison of the - mean post-pre acupuncture intervention pain intensity rating differences - and mean post-pre sham-acupuncture rating differences	15 minutes	In case of a significant effect in outcome 1, outcome 2 will be tested using a hierarchical procedure in order to avoid multiple testing.
Comparison of the - mean post-pre acupuncture intervention pain intensity rating differences - and mean post-pre control intervention (no acupuncture) rating differences	15 minutes

Secondary Outcome Measures

Name	Time	Method
Changes in heart rate variability (HRV) during the three intervention types (acupuncture, sham-Acupuncture, no acupuncture).	10 minutes	Comparison of changes in the HRV measured during the acupuncture/sham-acupuncture and no acupuncture
Changes in respiratory frequency during the three intervention types (acupuncture, sham-Acupuncture, no acupuncture).	10 minutes	Comparison of changes in respiratory frequency measured during the acupuncture/sham-acupuncture and no acupuncture.
Longer lasting effects of acupuncture on subjective intensity ratings	50 minutes	Besides the pre-post intervention comparisons (primary outcome), 2 additional timepoints (Total: pre-intervention, post-intervention, 15 min post-intervention, 30 min post-intervention) will be examined to test differences in temporal dynamics between the 3 intervention effects on subjective pain intensity.
Changes in skin conductance during the three intervention types (acupuncture, sham-Acupuncture, no acupuncture).	10 minutes	Comparison of changes in the skin conductance measured during the acupuncture/sham-acupuncture and no acupuncture
Frequency of SAEs	1 month	Serious adverse event (SAEs) occurrences will be recorded and their frequency will be calculated.
Longer lasting effects of acupuncture on pain-specific changes in heart rate.	50 minutes	Besides the pre-post intervention comparisons (primary outcome), 2 additional timepoints (Total: pre-intervention, post-intervention, 15 min post-intervention, 30 min post-intervention) will be examined to test differences in temporal dynamics between the 3 intervention effects on pain-specific heart rate alterations.
Longer lasting effects of acupuncture on pain-specific changes in skin conductance.	50 minutes	Besides the pre-post intervention comparisons (primary outcome), 2 additional timepoints (Total: pre-intervention, post-intervention, 15 min post-intervention, 30 min post-intervention) will be examined to test differences in temporal dynamics between the 3 intervention effects on pain-specific skin conductance alterations.
Longer lasting effects of acupuncture on pain-specific changes in respiratory frequency.	50 minutes	Besides the pre-post intervention comparisons (primary outcome), 2 additional timepoints (Total: pre-intervention, post-intervention, 15 min post-intervention, 30 min post-intervention) will be examined to test differences in temporal dynamics between the 3 intervention effects on pain-specific changes in respiratory frequency.

Trial Locations

Locations (2)

Clinic of Masticatory Disorders, Removable Prosthodontics, Geriatric and Special Care Dentistry Center of Dental Medicine University of Zurich; 🇨🇭 Zurich, Switzerland

Institute for Complementary and Integrative Medicine, University Hospital Zurich; 🇨🇭 Zurich, Switzerland