title: Evaluation of the Effects of Photobiomodulation on Bone Healing in Healthy and Streptozotocin-Induced Diabetes in Rats.
abstract: OBJECTIVE
  This study aimed to assess the effects of Photobiomodulation (PBM) with pulsed wave laser on Hounsfield unit (HU) and bone strength at a catabolic response (bone resorption) of a callus bone defect in healthy and streptozotocin (STZ)- induced type I diabetes mellitus (TI DM) in rats.
  
  
  BACKGROUND
  Conflicting results exist regarding the effect of PBM on bone healing in healthy and diabetic animals.
  
  
  METHODS
  We randomly divided 20 adult female rats into the following groups: (1) control, no TI DM, and no PBM; (2) no TI DM and PBM; (3) TI DM and no PBM; and (4) TI DM and PBM. TI DM was induced by STZ. All rats underwent partial transversal standardized osteotomies in their right tibias. The rats received PBM (890 nm, 80 Hz, 1.5 J/cm2) thrice per week during 30 days. At 4 weeks after the surgery, the rats were sacrificed and their tibias submitted to computed tomography scanning to measure HU. The samples underwent a three-point bending test to evaluate bone strength.
  
  
  RESULTS
  Analysis of variance (ANOVA) (p = 0.013) results showed that treatment by PBM significantly increased the biomechanical property (stress high load) of the callus defect from the partial tibia osteotomy in healthy rats compared to the control groups. However, we observed no significant increase in the biomechanical properties of the laser-treated diabetic bone defect compared to the control diabetic group. The ANOVA for the HU of callus density produced a p value of 0.000. A significant increase existed in the mean callus density in the healthy groups compared to the diabetic groups.
  
  
  CONCLUSIONS
  The 80-Hz laser did not significantly enhance bone repair from an osteotomy of the tibia in an experimental model of TI DM rats.
authors.affiliation: 1 Department of Biology and Anatomical Sciences, School of Medicine, Shahid Beheshti University of Medical Sciences , Tehran, Iran .
authors.forename: Ataroalsadat
authors.initials: A
authors.lastname: Mostafavinia
authors.affiliation: 2 School of medicine, Islamic Azad University , Tehran, Iran .
authors.forename: Sara
authors.initials: S
authors.lastname: Razavi
authors.affiliation: 3 Department of Anatomical sciences and Biology, School of Medicine, Shahid Beheshti University of Medical Sciences , Tehran, Iran .
authors.forename: Mohammadamin
authors.initials: M
authors.lastname: Abdollahifar
authors.affiliation: 3 Department of Anatomical sciences and Biology, School of Medicine, Shahid Beheshti University of Medical Sciences , Tehran, Iran .
authors.forename: Abdollah
authors.initials: A
authors.lastname: Amini
authors.affiliation: 4 Department of Statistics, Qom University , Qom, Iran .
authors.forename: Seyed Kamran
authors.initials: SK
authors.lastname: Ghorishi
authors.affiliation: 5 Celluar and Molecular Biology Research Center, Shahid Beheshti University of Medical Sciences , Tehran, Iran .
authors.forename: Fatemehalsadat
authors.initials: F
authors.lastname: Rezaei
authors.affiliation: 6 School of Medicine, Shahid Beheshti University of Medical Sciences , Tehran, Iran .
authors.forename: Ramin
authors.initials: R
authors.lastname: Pouriran
authors.affiliation: 5 Celluar and Molecular Biology Research Center, Shahid Beheshti University of Medical Sciences , Tehran, Iran .
authors.forename: Mohammad
authors.initials: M
authors.lastname: Bayat
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D001696:Biomechanical Phenomena; D001861:Bone Regeneration / Q000502:physiology / Q000528:radiation effects*; D003921:Diabetes Mellitus, Experimental; D004195:Disease Models, Animal; D005260:Female; D017102:Fracture Healing / Q000528:radiation effects; D028022:Low-Level Light Therapy / Q000379:methods*; D010027:Osteotomy / Q000379:methods*; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D012016:Reference Values; D013718:Tensile Strength / Q000528:radiation effects*; D013977:Tibia / Q000601:surgery
keywords: biomechanical properties; bone repair; diabetes mellitus; osteotomy; photobiomodulation; rat