The Effects of Photobiomodulation on Leukocyte and Platelet-Rich Fibrin as Barrier Membrane on Bone Regeneration: An Experimental Animal Study.

To compare the effects of leukocyte and platelet-rich fibrin (L-PRF) and photobiomodulation therapy (PBMT)-applied L-PRF (PBMT/L-PRF) as barrier membranes on new bone formation (BV/TV) for the treatment of critical-sized bone defects. The right iliac crests of five sheep were used in this experimental animal study. Eight critical-sized defects were surgically created in each sheep and a total of 40 defects were obtained. A deproteinized bovine bone graft was placed in all defects, and the defects were divided into four groups to be covered with L-PRF membrane, PBMT/L-PRF membrane, collagen membrane, or left uncovered as controls. Animals were sacrificed at 1 month. The sections obtained were histomorphometrically analyzed. The results showed that the collagen group presented significantly higher values for main bone healing parameters (BV/TV, bone volume, and bone surface;  < 0.05). The PBMT/L-PRF group presented higher values than the L-PRF group and controls for these parameters though not statistically significant ( > 0.05). The findings show that PBMT may provide additional regenerative properties to L-PRF when used as barrier membranes. However, these results did not reach the collagen membranes, which warrants further studies for adapting the laser parameters to increase regenerative capacity of L-PRF.