Effect of laser therapy on the prevention of postoperative pain in cases of endodontic urgency: a randomized clinical trial

Introduction: Postoperative pain is a complication that occurs after endodontic intervention with higher rates in teeth treated with previous emergency. An effective method for reducing symptoms in these cases is photobiomodulation therapy, which promotes analgesia, tissue regeneration and cell biostimulation. Objective: To investigate the intensity of postoperative pain after pulpectomy and the effect of using low-power laser for analgesia in teeth with irreversible pulpitis in permanent human teeth. Materials and methods: The study was a parallel blind randomized clinical trial with 42 patients, randomly allocated into two groups of 21 individuals, the Experimental Group using AsGaAl laser (wavelength 808nm) with a power of 100Mw, and the Control Group no laser. The NRS and VAS pain scales were applied, in addition to the use of a device to check sensitivity when biting. Postoperative pain in permanent teeth with irreversible pulpitis, as well as sensitivity when biting before and after emergency care, were evaluated. Demographic and medication characteristics were assessed for groups. Multiple intragroup analysis for spontaneous pain intensity was evaluated. Spontaneous pain intensity between groups was compared considering each assessment time. Results: There was a statistically significant difference on the NRS-10 scale between the groups after 12 hours (p = 0.042) and 24 hours (p = 0.022) of the procedure, indicating a higher peak of postoperative pain. For the VAS scale, there was only a statistically significant difference 24 hours after endodontic emergency care, which showed a significant increase (p = 0.019) in spontaneous pain. Conclusion: The application of low power laser was not effective/superior in analgesia of permanent teeth with symptomatic irreversible pulpitis.