Is laser acupuncture effective in controlling gag reflex while taking dental impressions? A randomized double-blinded sham-controlled clinical trial.

OBJECTIVE: The purpose of this study was to investigate the effect of laser acupuncture on controlling gag reflexes by stimulating pericardium 6 (PC6) and conception vessel 24 (CV24) acupuncture points in patients in need of taking dental impressions. METHODS: In this randomized controlled double-blinded clinical trial study, in 30 patients aged 20-60 years, alginate impressions were taken in the prosthetic and orthodontic clinic at the Dental School of Mashhad University of Medical Sciences, Mashhad, Iran. The participants were randomly divided into 2 groups. The intervention and the control group each included 15 subjects. Both groups were in the exact status of age, gender, and indexes, including the Gagging Severity Index (GSI), Subjective Severity of Gag Reflex (SSGR), Vomiting Number (VN), as well as the Improvement Index, measured. Both groups underwent alginate impressions pre-and postintervention. PC6 and CV24 acupuncture points were irradiated for 4 seconds in contact mode with a laser prob pressure on the skin that was slightly bleached without causing pain for the patient. The laser energy was 0.8 J with an energy density of 2.854 J/cm2 at the surface of the probe (spot size, 0.28 cm2). The total radiation dose was 45.7 J/cm2, and the power density was 714.2 w/cm2. RESULTS: The findings showed that SSGR and VN significantly improved (P ≤ .05) in the intervention group compared to the control group, but GSI was higher in the intervention group. In the intragroups analysis for the comparison between before and after the intervention, it was found that although the average GSI was elevated after the intervention rather than before, the difference was insignificant (P = .083). Also, after the intervention, the average SSGR was significantly reduced (P< .001), and VN was insignificantly lessened (P = .334). Moreover, it was observed after the intervention rather than before that GSI was significantly increased (P< .001), whereas SSGR significantly declined (P< .001), and VN meaningfully decreased (P = .001). The observations demonstrated that the Improvement Index status was significantly better in the intervention group compared to the control group (P = .002). CONCLUSION: This study found that the application of laser acupuncture on PC6 and CV24 acupuncture points might be effective in reducing the gag reflex and can be used as a noninvasive technique while taking dental impressions.