Effectiveness and acceleration of bone repair in critical‐sized rat calvarial defects using low‐level laser therapy

Abstract

Background and Objective Tissue regeneration remains a challenge for orthopedic and craniomaxillofacial surgery to treat bone loss. The use of low‐level laser therapy suggests a promise on this road with positive results for narrow defects. However, temporal and quantitative evaluations are required to understand the healing process of large injuries. The aim of this study was to investigate the repair of critical‐size bone defects in rat calvaria using a GaAlAs laser. Study Design/Materials and Methods Bone defects (9 mm in diameter) were created on the skull of 30 Wistar rats separated in control or irradiated group. GaAlAs laser (λ = 830 nm, energy density = 2.5 J/cm2 and output power = 50 mW) was applied after surgery and six times more at 48 hours intervals. The animals were euthanized after 2, 4, and 8 weeks. Digital radiographs, descriptive histological and histomorphometric analyses were carried out. Results Radiographic analysis showed greater bone formation in the irradiated group than control at 8 weeks, covering 45% and 28% of the defect, respectively (P < 0.05). Histological analysis showed in the irradiated groups a higher amount of bone neoformation and greater maturity at 4 and 8 weeks. Histomorphometric analysis showed that the volume density of bone tissue at 4 weeks in the irradiated group was two times higher than the control (P < 0.01). Conclusion The biomodulation of low‐level laser therapy using 830 nm wavelength light was effective in promoting bone healing in critical defects despite the unfavorable prognosis as well as it accelerated the maturation of bone tissue. Lasers Surg. Med. 46:61–67, 2014. © 2013 Wiley Periodicals, Inc.

Fibrin Sealant Derived from Human Plasma as a Scaffold for Bone Grafts Associated with Photobiomodulation Therapy

“…In the two analysed periods, the animals biostimulated with the laser presented greater evidence of new bone formation and greater tissue organisation at the end of the experiment [33]. These results are consistent with the literature that indicates the positive photobiomodulatory effects of the laser in the initial phases of bone repair, when, among several events, there is a proliferation of osteoblasts and differentiation of mesenchymal cells [34,35].…”

Effects of Photobiomodulation on Experimental Bone Repair in Animal models: a Systematic Review

“…Some studies used only one evaluation period, totaling:5 sessions 8-10 , 6 sessions 3,21 and 8 sessions 15,17 . Other studies have had two or more evaluation periods, such as: 6 and 18 sessions 18 ; 3, 6 and 9 sessions 13 ;3, 6 and 12 sessions 14 16 temporal and quantitative evaluations are required to understand the healing process of large injuries. The aim of this study was to investigate the repair of critical-size bone defects in rat calvaria using a GaAlAs laser.…”

“…There were no pig/sheep study models found within our inclusion criteria methods. Regarding defect localization, three different regions employed in the studies analyzed: calvaria 3,16,18,20 constituting a promising strategy to produce bone tissue healing. Objective: the aim of the present study was to investigate the in vivo performance of PBM using an experimental model of cranial bone defect in rats.…”

“…To evaluate biomodulation effects were utilized several types of analysis, included: histopathological or histological analysis (in the most of studies),morphometric analysis 3,8,10,12,[16][17][18][19]23 constituting a promising strategy to produce bone tissue healing. Objective: the aim of the present study was to investigate the in vivo performance of PBM using an experimental 0.1) Laser wavelengths (nm) According to the analyzed manuscripts, the GaAlAs laser wavelength varies between 650 to 830 nm, with the length of 830 nm being the most used [8][9][10][11][12][13][14][15][16] . Another studies evaluated GaAlAs (735 nm) 17 , GaAlAs (808 nm) 18 , He-Ne (632 nm) 19 , InGaAlP (660-690 nm) 13 , InGaAlP (685 nm) 15 .…”

“…Most PBM studies have described optical power, ranging from 0.03 W to 6 W, with 50 mW being used more. Several studies mentioned the power density, among them, 0.03 W [8][9][10][11]22 , 0.05 W 12,15,16,20 , 0.1 W 3,13,18,23 , 1.5, 3 and 6W 21 . Even though power density or irradiance W•cm-2 represents an important parameter in PBM, two studies not described this parameter17,19.…”