Efficacy of photobiomodulation using diode laser 650 nm combined with nano-cellulose and nano-amorphous calcium phosphate in bone healing of rabbit tibial defects assessed by H&E staining and computed tomography.

Background: The purpose of the current study was to evaluate the effect of Diode LLLT 650 nm, TEMPO oxidized Nano-fibrillated cellulose mixed with Nano-Amorphous calcium phosphate, and their combination on bone healing in rabbit tibia using H&E staining and computed tomography.

Methods: Eighteen adult male New Zealand rabbits were selected, two circular bone defects were created in each tibia, resulting in four bony defects in each rabbit, representing the four tested groups; group A (negative control), group B (filled with mineralized nano-cellulose), group C (combination), group D (laser). Animals were euthanized after two weeks and one month, defects were assessed by CT for bone density, then histological samples were examined by H&E stain.

Results: In both evaluation periods, group D recorded the greatest mean area percent of new bone formation and bone density, followed by group A, while group C recorded the lowest value. Groups A and D showed full closure of the defects, while groups B and C showed partial defect closure with retained bone graft material. H&E and CT showed that Laser group had the best results of defects healing, bone density and new bone formation, followed by the negative control group.

Conclusions: Diode laser 650nm photobiomodulation significantly improved bone defects healing. Mineralized nano-cellulose experimental bone substitute material showed a delayed effect in bone healing and graft material resorption. The combination of LLLT with the graft material had no positive outcome on bone defect healing.