Blood circulation changes in palatal gingiva before and after low-level laser irradiation in rats

Abstract

Introduction: Clinical practice with low-level laser therapy (LLLT) has been investigated; however researchers and therapists have questioned the clinical benefits of laser therapy due to divergent results in the literature. Aim of the study: This research evaluated the effects of laser therapy on blood circulation following application of two diode lasers with different wavelengths with laser Doppler flowmetry (LDF). Materials and Methods: In order to evaluate the effectiveness of LLLT on circulation of blood vessels in palatal gingiva, two diode lasers were applied to the palatal gingiva at 2 mm distance to the two upper incisors of 20 rats. Ten rats were irradiated with a wavelength of 810 nm (10 J/cm 2 , Fotona) while other 10 rats were irradiated with wavelength of 660 nm (10 J/cm 2 , Helbo, Bredent) for 7 consecutive days. Rate of blood circulation in the ascending palatine artery was determined with LDF from the same gingival location before and 1 h after irradiation on each day. Data were analyzed by repeated measurements of analysis of variance (ANOVA). Results: The results indicated that blood circulation was significantly increased after 1 h following irradiation with both diode laser types ( P Conclusion: The irradiation of the palatal gingiva by LLLT enhanced the local blood circulation; however, the amount of increase was limited and similar to following identical applications on consecutive days.