Effect of 830-nm laser light on the repair of bone defects grafted with inorganic bovine bone and decalcified cortical osseous membrane.
OBJECTIVE
The aim of this study was to assess histologically the effect of LLLT (lambda830 nm) on the repair of standardized bone defects on the femur of Wistar albinus rats grafted with inorganic bovine bone and associated or not to decalcified bovine cortical bone membrane.


BACKGROUND
Bone loss may be a result of several pathologies, trauma or a consequence of surgical procedures. This led to extensive studies on the process of bone repair and development of techniques for the correction of bone defects, including the use of several types of grafts, membranes and the association of both techniques. There is evidence in the literature of the positive effect of LLLT on the healing of soft tissue wounds. However, its effect on bone is not completely understood.


METHODS
Five randomized groups were studied: Group I (Control); Group IIA (Gen-ox); Group IIB (Gen-ox + LLLT); Group IIIA (Gen-ox + Gen-derm) and Group IIIB (Gen-ox + Gen-derm + LLLT). Bone defects were created at the femur of the animals and were treated according to the group. The animals of the irradiated groups were irradiated every 48 h during 15 days; the first irradiation was performed immediately after the surgical procedure. The animals were irradiated transcutaneously in four points around the defect. At each point a dose of 4 J/cm2 was given (phi approximately 0.6 mm, 40 mW) and the total dose per session was 16 J/cm2. The animals were humanely killed 15, 21, and 30 days after surgery. The specimens were routinely processed to wax, serially cut, and stained with H&E and Picrosirius stains and analyzed under light microscopy.


RESULTS
The results showed evidence of a more advanced repair on the irradiated groups when compared to non-irradiated ones. The repair of irradiated groups was characterized by both increased bone formation and amount of collagen fibers around the graft within the cavity since the 15th day after surgery, through analysis of the osteoconductive capacity of the Gen-ox and the increment of the cortical repair in specimens with Gen-derm membrane.


CONCLUSIONS
It is concluded that LLLT had a positive effect on the repair of bone defect submitted the implantation of graft.
Barbos Pinheiro
Antonio Luiz
AL
Laser Center, School of Dentistry, Federal University of Bahia, Salvador, Brazil. albp@ufba.br
Limeira Júnior
Francisco De Assis
Fde A
Márquez Gerbi
Marleny Elizabeth
ME
Pedreira Ramalho
Luciana Maria
LM
Marzola
Clovis
C
Carneiro Ponzi
Elizabeth Arruda
EA
Oliveira Soares
André
A
Bandeira De Carvalho
Livia Cristina
LC
Vieira Lima
Helena Cristina
HC
Oliveira Gonçalves
Thais
T
D000818:Animals; D001672:Biocompatible Materials; D003648:Decalcification Technique; D005260:Female; D028022:Low-Level Light Therapy; D008297:Male; D008567:Membranes, Artificial; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D014945:Wound Healing / Q000528:radiation effects*
D001672:Biocompatible Materials; D008567:Membranes, Artificial