New method for postoperative pain relief using a combination of noxious and non-noxious stimuli after impacted wisdom tooth extraction.

Although in clinical dentistry the major method used for pain relief is oral administration of analgesics, alternative methods are available, such as transcutaneous electrical nerve stimulation (TENS), acupuncture, vibration and conditioned pain modulation (CPM), formerly termed diffuse noxious inhibitory control. The aim of the present study was to investigate the combined effects of non-noxious (TENS) and noxious (CPM) stimuli on postoperative pain after extraction of an impacted wisdom tooth. The study involved 44 patients who were scheduled to undergo impacted wisdom tooth extraction. The patients were randomly allocated into four groups: noxious stimuli, non-noxious stimuli, combined noxious and non-noxious stimuli, and a sham group. On the day after tooth extraction, stimulation procedures for pain relief were performed and changes in the level of perceived pain were scored using a visual analog scale (VAS). The combination of non-noxious and noxious stimuli decreased the VAS scores by 63.7%, indicating a more potent analgesic effect than that in the non-noxious, noxious, and sham groups. This method of analgesia using a combination of non-noxious and noxious stimuli can be applied to patients who are unable to tolerate analgesics, such as those with allergy, hypersensitivity or digestive disorders, and those who are pregnant.