Effects of Light-Emitting Diode Photobiomodulation Therapy and BioOss as Single and Combined Treatment in an Experimental Model of Bone Defect Healing in Rats
The present study assesses histopathologically and histomorphometrically the effects of light-emitting diode (LED) photobiomodulation therapy (LPT) on bone healing in BioOss-filled femoral defects of rats. It has been reported that LPT modulates cellular metabolic processes, leading to an enhanced regenerative potential for biological tissues. Thirty-six male Wistar rats with femoral bone defects were divided into 4 groups: defect group (empty bone defect, without application of LPT), graft group (bone defect filled with BioOss, without application of LPT), (defect+LPT) group (empty bone defect, with application of LPT), and (graft+LPT) group (bone defect filled with BioOss, with application of LPT). An OsseoPulse LED device (wavelength: 618 nm; output power: 20 mW/cm2) was initiated 24 hours postsurgery and performed every 24 hours for 7, 14, and 21 days. The LPT-applied and BioOss-filled defects presented a higher amount of new bone formation with trabeculae formation. These defects showed statistically significant lower values of inflammation severity, and fewer remnants of biomaterial were present. Within the limitations of this study, LPT has positive effects on bone healing histopathologically and histomorphometrically for the defects filled with BioOss 3 weeks after the rats' femora injury.
Standardized 3-mm diameter bone defects: (a) defect filled with BioOss; (b) empty defect.
(a) Photomicrographs of bone tissue sections from femurs of animals in week 1 stained with hematoxylin and eosin in the defect group, showing details of severe inflammatory infiltrate areas (asterisks) and minimal vascularization (asterisks) as well as new bone with weak trabecular structure (arrows; magnifications; ×40 and ×200). (b) Photomicrographs of bone tissue sections from femurs of animals in week 1 stained with hematoxylin and eosin in the graft group, showing details of severe inflammatory infiltrate areas (asterisks), moderate vascularization (asterisks), and pronounced new bone formation and trabecular bone structure (arrows) as well as remnants of biomaterial in some areas (double arrow; magnifications: ×40 and ×200). (c) Photomicrographs of bone tissue sections from femurs of animals in week 1 stained with hematoxylin and eosin in the (defect+light-emitting diode photobiomodulation therapy [LPT]) group, showing details of severe inflammatory infiltrate areas (asterisks) and moderate vascularization (asterisks) as well as an increase in osteoblasts and trabecular bone structure (arrows; magnifications: ×200 and ×400). (d) Photomicrographs of bone tissue sections from femurs of animals in week 1 stained with hematoxylin and eosin in the (graft+LPT) group, showing details of severe inflammatory infiltrate areas (asterisks), moderate vascularization (asterisks), pronounced trabecular bone structure, and presence of osteoblasts (arrows) as well as remnants of biomaterial in some areas (arrow heads; magnifications: ×200 and ×400).
(a) Photomicrographs of bone tissue sections from femurs of animals in week 2 stained with hematoxylin and eosin in the defect group, showing details of severe inflammatory infiltrate areas (asterisks), moderate vascularization (asterisks), and osteoblastic activity (arrows), as well as new osteocyte (arrow heads) formations (magnifications: ×40 and ×200). (b) Photomicrographs of bone tissue sections from femurs of animals in week 2 stained with hematoxylin and eosin in the graft group, showing details of severe inflammatory infiltrate areas (asterisks), moderate vascularization (asterisks), as well as presence increased osteoblastic activity (arrow heads) and osteoid matrix formation (arrows; magnifications: ×200 and ×400). (c) Photomicrographs of bone tissue sections from femurs of animals in week 2 stained with hematoxylin and eosin in the (defect+light-emitting diode photobiomodulation therapy [LPT]) group, showing details of severe inflammatory infiltrate areas (asterisks), moderate vascularization (asterisks), well-developed trabecular bone structure (arrow head), and osteoblastic activity (arrows) as well as remnants of biomaterials (double arrow; magnifications: ×40 and ×200). (d) Photomicrographs of bone tissue sections from femurs of animals in week 2 stained with hematoxylin and eosin in the (graft+LPT) group, showing details of severe inflammatory infiltrate areas (asterisks), severe vascularization (asterisks), pronounced trabecular bone structure (arrows), as well as remnants of biomaterial in some areas (double arrow; magnifications: ×100 and ×200).
(a) Photomicrographs of bone tissue sections from femurs of animals in week 3 stained with hematoxylin and eosin in the defect group, showing details of severe inflammatory infiltrate areas (asterisks) and moderate vascularization (asterisks) as well as well-organized trabecular bone structure (arrows), osteoblasts (arrow heads), and osteocytes embedded inside the osteoid matrix (wavy line; magnifications: ×100 and ×200). (b) Photomicrographs of bone tissue sections from femurs of animals in week 3 stained with hematoxylin and eosin in the graft group, showing details of severe inflammatory infiltrate areas (asterisks), moderate vascularization (asterisks), well-developed trabecular bone structure (arrows), and osteoid matrix formation (arrow head) as well as remnants of biomaterial in some areas (double arrow; magnifications: ×100 and ×200). (c) Photomicrographs of bone tissue sections from femurs of animals in week 3 stained with hematoxylin and eosin in the (defect+light-emitting diode photobiomodulation therapy [LPT]) group, showing details of severe inflammatory infiltrate areas (asterisks) and moderate vascularization (asterisks) as well as well-developed trabecular bone structure (arrows) and osteoblastic activity (arrow heads; magnifications: ×200 and ×400). (d) Photomicrographs of bone tissue sections from femurs of animals in week 3 stained with hematoxylin and eosin in the (graft+LPT) group, showing details of severe inflammatory infiltrate areas (asterisks) and severe vascularization (asterisks), pronounced trabecular bone structure, and presence of osteoid matrix formation (arrows) as well as remnants of biomaterial (arrow heads) inside the trabecular bone (magnifications: ×100 and ×200).
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