Bone Healing Research
Clinical Studies
Abe, T. (1989). LLLT using a Diode Laser in Successful Treatment of a Herniated Lumbar/Sacral Disc, with Magnetic Resonance Imaging (MRI) Assessment: A Case Report. Laser Therapy. John Wiley & Sons.
Sousa G R, Ribeiro M S, Groth E B. (2002). Bone repair of the periapical lesions treated or not with low intensity laser (wavelength=904 nm). Laser Surg Med. Abstract Issue 2002. abstract 303.
Experimental Studies
Tajali S B, MacDermid J C, Houghton P, and Grewal R (2010). Effects of low power laser irradiation on bone healing in animals: a meta-analysis. Journal of Orthopeadic Surgery and Research 2010, 5:1. Abstract: Purpose: The meta-analysis was performed to identify animal research defining the effects of low power laser irradiation on biomechanical indicators of bone regeneration and the impact of dosage. Method: We searched five electronic databases (MEDLINE, EMBASE, PubMed, CINAHL, and Cochrane Database of Randomised Clinical Trials) for studies in the area of laser and bone healing published from 1966 to October 2008. Included studies had to investigate fracture healing in any animal model, using any type of low power laser irradiation, and use at least one quantitative biomechanical measures of bone strength. There were 880 abstracts related to the laser irradiation and bone issues (healing, surgery and assessment). Five studies met our inclusion criteria and were critically appraised by two raters independently using a structured tool designed for rating the quality of animal research studies. After full text review, two articles were deemed ineligible for meta-analysis because of the type of injury method and biomechanical variables used, leaving three studies for meta-analysis. Maximum bone tolerance force before the point of fracture during the biomechanical test, 4 weeks after bone deficiency was our main biomechanical bone properties for the Meta analysis.
Results: Studies indicate that low power laser irradiation can enhance biomechanical properties of bone during fracture healing in animal models. Maximum bone tolerance was statistically improved following low level laser irradiation (average random effect size 0.726, 95% CI 0.08 - 1.37, p 0.028). While conclusions are limited by the low number of studies, there is concordance across limited evidence that laser improves the strength of bone tissue during the healing process in animal models.
Ozawa Y; Shimizu N; Kariya G; Abiko Y (1998). Low-Energy Laser Irradiation Stimulates Bone Nodule Formation At Early Stages Of Cell Culture In Rat Calvarial Cells. Bone 22 (4): 347-354. Abstract: To determine the target cells responsible for the action of laser irradiation and roles of irradiation on these cells during bone formation, we investigated the effects of low-energy laser irradiation at various cell culture stages on cellular proliferation, bone nodule formation, alkaline phosphatase activity, and osteocalcin gene expression, employing rat calvarial cells. Osteoblast-like cells isolated from fetal rat calvariae were irradiated once with a low-energy Ga-Al-As laser (830 nm, 500 mW) at various cell culture stages (days 1-16). Laser irradiation at early stages of culture significantly stimulated cellular proliferation, ALP activity, and osteocalcin gene expression thereafter. Furthermore, laser irradiation at earlier stages of culture significantly stimulated a greater number (1.7-fold) and larger area (3.4-fold) of bone nodules that had developed in the culture dish on day 21. However, these effects could not be found by irradiation at a later date. These results suggest that laser irradiation may play two principal roles in stimulating bone formation. One is stimulation of cellular proliferation, especially proliferation of nodule-forming cells of osteoblast lineage, and the other is stimulation of cellular differentiation, especially to committed precursors, resulting in an increase in the number of more differentiated osteoblastic cells and an increase in bone formation. Both bone-formation-stimulating roles may be exhibited by laser irradiation to immature cells only.
Ribeiro D A and Matsumoto M A (2008) Low-level laser therapy improves bone repair in rats treated with anti-inflammatory drugs. Journal of Oral Rehabiliation Vol 35: 12 925-933 Dec 08
Abstract: Nowadays, selective cyclooxygenase-2 non-steroidal anti-inflammatory drugs have been largely used in surgical practice for reducing oedema and pain. However, the association between these drugs and laser therapy is not known up to now. Herein, the aim of this study was to evaluate the action of anti-COX-2 selective drug (celecoxib) on bone repair associated with laser therapy. A total of 64 rats underwent surgical bone defects in their tibias, being randomly distributed into four groups: Group 1) negative control; Group 2) animals treated with celecoxib; Group 3) animals treated with low-level power laser and Group 4) animals treated with celecoxib and low-level power laser. The animals were killed after 48 h, 7, 14 and 21 days. The tibias were removed for morphological, morphometric and immunohistochemistry analysis for COX-2. Statistical significant differences (P < 0·05) were observed in the quality of bone repair and quantity of formed bone between groups at 14 days after surgery for Groups 3 and 4. COX-2 immunoreactivity was more intense in bone cells for intermediate periods evaluated in the laser-exposed groups. Taken together, such results suggest that low-level laser therapy is able to improve bone repair in the tibia of rats as a result of an up-regulation for cyclooxygenase-2 expression in bone cells.
Silva Junior A, Pinheiro A, Oliveira M et al. (2002). Computerized Morphometric Assessment Of The Effect Of Low-Level Laser Therapy On Bone Repair: An Experimental Animal Study. Journal of Clinical Laser Medicine & Surgery, 20 (2): 83-87.
Trelles, M.A. & Mayayo, E. (1987). Bone Fracture Consolidates Faster With Low Power Laser. Lasers in Surgery and Medicine 7 (1) 36-45.
Glinkowski W, Rowinski J (1995). Effect Of Low Incident Levels Of Infrared Laser Energy On The Healing Of Experimental Bone Fractures. Laser Therapy, 7: 67-70.
Chen, J., & Zhou, Y. (1989). Effect of Low Level Carbon Dioxide Laser Radiation on Biochemical Metabolism of Rabbit Mandibular Bone Callus. Laser Therapy. John Wiley & Sons.
David R, Nissan M, Cohen I, Soudry M.(1996). Effect of low-power He- Ne laser on fracture healing in rats. Lasers Surg Med, 19: 458-464.
In Vitro Studies
Bassleer, C., Dachy,M., Reginster, J.Y., Gysen, P., Bassleer, R., Franchimont, P. (1985). Human Articular Chondrocytes Cultivated in Three Dimensions: Effects of I.R. Laser Irradiation. International Congress on Laser in Medicine and Surgery, Bologna: 381-385.