Effect of low level laser therapy on the repair of bone defects grafted with inorganic bovine bone

Abstract

The aim of this study was to assess histologically the effect of LLLT (λ 830 nm) on the repair of standardized bone defects on the femur of Wistar albinus rats which were grafted with inorganic bovine bone Gen-ox ® . Three randomized groups were studied: group I (control, n=6); group II (Gen-ox ® , n=9) and group III (Gen-ox ® + LLLT, n=9). The animals were irradiated every 48 h during 15 days; the first irradiation was performed immediately after the procedure. The animals were irradiated transcutaneuosly at four points around the defect. At each point a dose of 4 J/cm 2 was given (Ø~0.6 mm, 40 mW) and the total dose per session was 16 J/cm 2 . The animals were killed by an overdose of general anesthetic 15, 21 and 30 days after surgery. The specimens were routinely processed by embedding in paraffin, serially cut and stained with H&E and Picrosirius and analyzed under light microscopy. The results showed evidence of a more advanced repair in the irradiated group when compared to the non-irradiated groups. The repair of the irradiated group was characterized by both increased bone formation and amount of collagen fibers around the graft within the cavity from the 15th day after surgery, also considering the osteoconductive capacity of the Gen-ox ® . We conclude that LLLT had a positive effect on the repair of bone defects implanted with inorganic bovine bone.

Estudo morfométrico da terapia LED de baixa potência em tendinite de ratos

“…Estudos demonstram ainda que a utilização da terapia LED de baixa potência pode ser eficiente para prevenção da geração de cáries, com efeito bactericida, alívio da dor na cicatrização [21][22][23] e reparação óssea 24,25 , demonstrando a versatilidade da aplicação do LED. Além disso, abre novas perspectivas para futuros estudos de associação, pois a sua aplicação parece apresentar efeitos benéficos para a tendinite.…”

Regeneration Approaches for Dental Pulp and Periapical Tissues with Growth Factors, Biomaterials, and Laser Irradiation

“…In contrast, several lines of studies reported that the combination of LILT with growth factors or biomaterials accelerates osteoblast differentiation and bone regeneration. It has been indicated that the combination of LILT with graft of autologous bone or inorganic bovine bone [71][72][73][74], enamel matrix derivative [75], and BMPs [76][77][78] accelerated bone regeneration, compared with LILT alone or biomaterials alone. Recently, we examined effects of LILT by Ga-Al-As laser on BMP2 induced osteoblastogenesis [79], and found that low intensity laser irradiation accelerated BMP2-induced transcription factors such as Id1, Osterix, and Runx2, expressions of type I collagen, osteonectin, and osteocalcin mRNA, markers of osteoblasts, and activation of Smad1/5/8 as well as alkaline phosphatase, in C2C12 myoblast cells that differentiate into osteoblasts by exposure to BMP2.…”

Infrared Laser Photobiomodulation (λ 830 nm) on Bone Tissue Around Dental Implants: A Raman Spectroscopy and Scanning Electronic Microscopy Study in Rabbits

“…2 Different techniques-such as the use of grafts, biomaterials, [3][4][5] bone transplants, 3 and the application of biostimulators such as ultrasound 6 -have been used in dentistry with the ultimate aim of improving the quality of bone around dental implants. Most recently, the use of laser photobiomodulation has been successfully used to improve bone quality.…”

“…3,9,10 Several studies have demonstrated that near IR (infrared) laser photobiomodulation is the most suitable for bone repair, due to its higher penetration depth on the bone tissue when compared to the visible laser. [2][3][4][5]11 Although microscopic examination and image examinations are the most frequently used methods for assessment of bone healing around dental implants, these methods are unable to provide information at the molecular level. 12,13 An alternative method is near infrared Raman spectroscopy (NIRS), which has been used in several noninvasive diagnostic applications of biological samples such as several types of cancers, 14 human coronary arteries, 15 22 to evaluate the microstructure of human cortical bone (osteon), 23 and to investigate the long-term effects on the surface microstructure of hydroxyapatite disks implanted inside articular capsules of mice.…”