title: The effects of combined low level laser therapy and mesenchymal stem cells on bone regeneration in rabbit calvarial defects.
abstract: OBJECTIVE
  This study evaluated the effect of Low Level Laser Therapy (LLLT) and Mesenchymal Stem Cells (MSCs) on bone regeneration.
  
  
  BACKGROUND
  Although several studies evaluated the effects of MSCs and LLLT, there is little information available regarding in vivo application of LLLT in conjunction with MSCs.
  
  
  METHODS
  Forty-eight circular bone defects (6mm in diameter) were prepared in the calvaria of 12 New-Zealand white rabbits. The defects of each animal were randomly assigned to 4 groups: (C) no treatment; (L) applying LLLT; (SC) filled with MSCs; (SCL) application of both MSCs and LLLT. LLL was applied on alternate days at wavelength of 810 nm, power density of 0.2 W/cm(2) and a fluency of 4 J/cm(2) using a Gallium-Aluminum-Arsenide (GaAlAs) diode laser. The animals were sacrificed after 3 weeks and then histological samples were evaluated to determine the amount of new bone formation and the remaining scaffold and inflammation.
  
  
  RESULTS
  The histological evaluation showed a statistically significant increase in new bone formation of LLLT group relative to the control and the other two experimental groups (p<0.05). There was no significant difference in bone formation of the control group compared to experimental groups filled with MSCs. Laser irradiation had no significant effect on resorption of the scaffold material. In addition, inflammation was significantly reduced in LLLT group compared to the control defects and the other two experimental groups.
  
  
  CONCLUSIONS
  Low level laser therapy could be effective in bone regeneration but there is no evidence of a synergistic effect when applied in conjunction with MSCs.
authors: Dental Department, AJA University of Medical Sciences, Tehran, Iran. Electronic address: rezafekrazad@gmail.com.
authors: R
authors: R
authors: Fekrazad
authors: Gorgan Faculty of Dentistry, Golestan University of Medical Sciences, Golestan, Iran. Electronic address: moss.sadeghi@gmail.com.
authors: M
authors: M
authors: Sadeghi Ghuchani
authors: Department of Stem Cells and Developmental Biology, Cell Science Research Center, Royan Institute for Stem Cell Biology and Technology, ACECR, Tehran, Iran. Electronic address: eslami@royaninstitute.org.
authors: M B
authors: MB
authors: Eslaminejad
authors: Department of Stem Cells and Developmental Biology, Cell Science Research Center, Royan Institute for Stem Cell Biology and Technology, ACECR, Tehran, Iran. Electronic address: leila_taghiyar@yahoo.com.
authors: L
authors: L
authors: Taghiyar
authors: Iranian Medical Laser Association, Tehran, Iran. Electronic address: kathykalhor@yahoo.com.
authors: K A M
authors: KA
authors: Kalhori
authors: Department of Clinical Sciences, Faculty of Veterinary Medicine, University of Tehran, Iran. Electronic address: mpedram@ut.ac.ir.
authors: M S
authors: MS
authors: Pedram
authors: Tabriz Faculty of Dentistry, Tabriz University of Medical Sciences, Tabriz, Iran. Electronic address: sh_arman_ima@yahoo.com.
authors: A M
authors: AM
authors: Shayan
authors: Department of Stem Cells and Developmental Biology, Cell Science Research Center, Royan Institute for Stem Cell Biology and Technology, ACECR, Tehran, Iran. Electronic address: Nasser.Aghdami@ki.se.
authors: N
authors: N
authors: Aghdami
authors: Laser Research Center, Faculty of Health Sciences, University of Johannesburg, South Africa. Electronic address: habrahamse@uj.ac.za.
authors: H
authors: H
authors: Abrahamse
mesh_terms: D000818:Animals; D064592:Autografts; D001861:Bone Regeneration / Q000502:physiology / Q000528:radiation effects*; D028022:Low-Level Light Therapy / Q000379:methods*; D008297:Male; D045164:Mesenchymal Stem Cell Transplantation / Q000379:methods*; D059630:Mesenchymal Stem Cells / Q000166:cytology / Q000502:physiology; D011817:Rabbits; D012886:Skull / Q000293:injuries / Q000601:surgery; D054457:Tissue Scaffolds
keywords: Animal study; Bone regeneration; Low Level Laser Therapy (LLLT); Stem cell