Effect of intraoral or extraoral photobiomodulation on oral mucositis induced by chemotherapy in rats

Purpose: To compare the effect of intraoral (IO) and extraoral (EO) diode laser irradiation on oral mucositis (OM) induced by 5- fluorouracil (5-FU) in rats. Study Design: Seventy-eight male Wistar rats were divided into the following groups: negative control (NC), positive control (PC), IO 6 J/cm2, EO with 6 J/cm2, and EO with 12 J/cm2. OM was induced with an intraperitoneal injection of 5-FU and scarification of the buccal mucosa. Animals received photobiomodulation (PBM) daily. Clinical, histologic, and redox state evaluations were performed at days 8, 10, and 14. Results: Clinically, on day 8, EO 6 J/cm2 showed a lower score compared to PC (P< .05). On days 10 and 14, all PBM groups exhibited improvement of OM compared to PC (P< .01). Histologically, on day 8, all PBM groups exhibited an accelerated healing process compared to PC (P< .01) and reduction of reactive species (P< .001). Also, all PBM groups demonstrated higher levels of antioxidant GPx compared to PC (P< .001). Conclusions: An EO diode laser protocol promoted positive effects in the clinical, histopathological, and redox state in OM induced by 5-FU in rats. Among the EO protocols, EO 6 J/cm2 showed the most encouraging results. Purpose: To compare the effect of intraoral (IO) and extraoral (EO) diode laser irradiation on oral mucositis (OM) induced by 5- fluorouracil (5-FU) in rats. Study Design: Seventy-eight male Wistar rats were divided into the following groups: negative control (NC), positive control (PC), IO 6 J/cm2, EO with 6 J/cm2, and EO with 12 J/cm2. OM was induced with an intraperitoneal injection of 5-FU and scarification of the buccal mucosa. Animals received photobiomodulation (PBM) daily. Clinical, histologic, and redox state evaluations were performed at days 8, 10, and 14. Results: Clinically, on day 8, EO 6 J/cm2 showed a lower score compared to PC (P< .05). On days 10 and 14, all PBM groups exhibited improvement of OM compared to PC (P< .01). Histologically, on day 8, all PBM groups exhibited an accelerated healing process compared to PC (P< .01) and reduction of reactive species (P< .001). Also, all PBM groups demonstrated higher levels of antioxidant GPx compared to PC (P< .001). Conclusions: An EO diode laser protocol promoted positive effects in the clinical, histopathological, and redox state in OM induced by 5-FU in rats. Among the EO protocols, EO 6 J/cm2 showed the most encouraging results.