Short-pulse neodymium:yttrium-aluminium garnet (Nd:YAG 1064Â nm) laser irradiation photobiomodulates mitochondria activity and cellular multiplication of Paramecium primaurelia (Protozoa)

Few studies exist to explore the potential photobiomodulation (PBM) effect of neodymium:yttrium-aluminium garnet (Nd:YAG) laser irradiation using a flat-top handpiece delivery system. In this study, we explored the photobiomodulation effect of that laser, on Paramecium primaurelia. The parameters for the different study groups were: 0.50 W, 10 Hz, 100 msp, 30 J/cm2; 0.75 W, 10 Hz, 100 msp, 45 J/cm2; 1.00 W, 10 Hz, 100 msp, 60 J/cm2; 1.25 W, 10 Hz, 100 msp, 75 J/cm2 and 1.50 W, 10 Hz, 100 msp, 90 J/cm2. Our results suggest that only the parameter 0.5 W, 10 Hz, 100 msp, 30 J/cm2 positively photobiomodulates the Paramecium cells inducing an increment in oxygen consumption, endogenous ATP synthesis and fission rate rhythm. Applying the laser energy with parameters of 1.25 W, 10 Hz, 100 msp, 75 J/cm2 and 1.50 W, 10 Hz, 100 msp, 90 J/cm2, induce adverse effect on the Paramecium cells, which protect themselves through the increase in Heat Shock Protein-70 (HSP70). The data presented in our work support our assumption that, when using appropriate parameters of irradiation, the 1064 nm Nd:YAG laser with flat-top handpiece could be a valuable aid for effective clinical application of PBM.