High-intensity Nd:YAG laser accelerates bone regeneration in calvarial defect models

Abstract

High-power pulsed lasers have been recently regarded to be anabolic to bone, but in vivo evidence is still lacking. This study aimed to investigate the capacity of bone repair using a high-power, Q-switched, pulsed, neodymium-doped yttrium aluminium garnet (Nd:YAG) laser, using bilateral calvarial defect models having non-critical sized, 5 mm (rat) or 8 mm (rabbit) diameter. One of the bilateral defects, which were all filled with collagen sponge or left empty, was irradiated with a Nd:YAG laser once every 2 days for 2 weeks at a constant total fluence rate (344 J/cm(2) ), output power (0.75 W), pulse repetition rate (15 pps) and wavelength (1064 nm) and examined for the laser effect. The same experimental scheme was designed using a rabbit calvarial defect model implanted with sponge, which was explored for the dose effect of output power at 0.75 and 3 W with the same quantities of the other parameters. New bone formation was evaluated by micro-computed tomography-based analysis and histological observation at 4 weeks after surgery. Laser irradiation significantly increased new bone formation by approximately 45%, not only in the sponge-filled defects of rats but also when the defects were left empty, compared to the non-irradiated group. Consistently, both doses of output power (0.75 and 3 W) enhanced new bone formation, but there was no significant difference between the two doses. This study is one of the first to demonstrate the beneficial effect of Nd:YAG lasers on the regeneration of bone defects which were left empty or filled with collagen sponge, suggesting its great potential in postoperative treatment targeting local bone healing.

Periodontal and peri‐implant wound healing following laser therapy

“…Kim et al. also investigated the capacity of bone repair using a high‐intensity, Q‐switched Nd:YAG laser in postoperative treatment targeting local bone healing. Laser irradiation significantly increased new‐bone formation by approximately 45%, not only in the collagen sponge‐filled defects of rats but also when the defects were left empty, compared with the nonirradiated group.…”

Adjunctive Nd:YAG Laser Irradiation for Ridge Preservation and Immediate Implant Procedures: A Consecutive Case Series

“…Additionally, Nd:YAG laser irradiation attenuated lipopolysaccharide‐mediated inflammatory responses of macrophages and endothelial cells in vitro . Thus, at immediate implant and ridge preservation sites, Nd:YAG laser application possibly promotes bone healing, suppresses bacteria, and modulates the immune response …”

“…Nd:YAG laser output may positively influence hard and soft tissue wound healing . Possible effects of Nd:YAG laser energy, based on animal and in vitro studies, include induction of preosteoblast bone morphogenetic protein‐2 expression, stimulation of osteoblast differentiation, and acceleration of bone regeneration . Nd:YAG laser energy applied in human periodontal pockets suppressed selected pathogens below culture detection limits in 85% of patients .…”

“…[8][9][10][11] Possible effects of Nd:YAG ¶ Replace Select Tapered, Nobel Biocare, Kloten, Switzerland # OraGRAFT, Lifenet Health, Virginia Beach, VA laser energy, based on animal and in vitro studies, include induction of preosteoblast bone morphogenetic protein-2 expression, 8 stimulation of osteoblast differentiation, 9 and acceleration of bone regeneration. 10 Nd:YAG laser energy applied in human periodontal pockets suppressed selected pathogens below culture detection limits in 85% of patients. 12 Additionally, Nd:YAG laser irradiation attenuated lipopolysaccharide-mediated inflammatory responses of macrophages and endothelial cells in vitro.…”

Management of an Immediate Implant Horizontal Defect Using Freeze‐Dried Bone Allograft and a Neodymium:Yttrium‐Aluminum‐Garnet Laser

“…In in vitro studies Nd:YAG laser energy has been found to induce preosteoblast bone morphogenetic protein‐2 expression, 7 stimulate osteoblast proliferation and differentiation, 8 increase osteoblast intracellular calcium, 9 and stimulate fibroblast proliferation and epidermal growth factor secretion 10 . In animal models, Nd:YAG laser energy markedly enhanced collagen III biosynthesis 11 and accelerated bone formation compared with controls 12 . Additionally, low‐level Nd:YAG irradiation may modulate the inflammatory response and thus affect wound healing 13 …”