title: Impact of bone harvesting techniques on cell viability and the release of growth factors of autografts.
abstract: BACKGROUND
  Autogenous bone grafts obtained by different harvesting techniques behave differently during the process of graft consolidation; the underlying reasons are however not fully understood. One theory is that harvesting techniques have an impact on the number and activity of the transplanted cells which contribute to the process of graft consolidation.
  
  
  METHODS
  To test this assumption, porcine bone grafts were harvested with four different surgical procedures: bone mill, piezosurgery, bone drilling (bone slurry), and bone scraper. After determining cell viability, the release of molecules affecting bone formation and resorption was assessed by reverse transcription polymerase chain reaction and immunoassay. The mitogenic and osteogenic activity of the conditioned media was evaluated in a bioassay with isolated bone cells.
  
  
  RESULTS
  Cell viability and the release of molecules affecting bone formation were higher in samples harvested by bone mill and bone scraper when compared with samples prepared by bone drilling and piezosurgery. The harvesting procedure also affected gene expression, for example, bone mill and bone scraper samples revealed significantly higher expression of growth factors such as bone morphogenetic protein-2 and vascular endothelial growth factor compared with the two other modalities. Receptor activator of nuclear factor kappa B ligand expression was lowest in bone scraper samples.
  
  
  CONCLUSIONS
  These data can provide a scientific basis to better understand the impact of harvesting techniques on the number and activity of transplanted cells, which might contribute to the therapeutic outcome of the augmentation procedure.
authors.affiliation: Department of Oral Surgery and Stomatology, School of Dental Medicine, University of Bern, Bern, Switzerland. richard.miron@zmk.unibe.ch
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Miron
authors.forename: Reinhard
authors.initials: R
authors.lastname: Gruber
authors.forename: Erik
authors.initials: E
authors.lastname: Hedbom
authors.forename: Nikola
authors.initials: N
authors.lastname: Saulacic
authors.forename: Yufeng
authors.initials: Y
authors.lastname: Zhang
authors.forename: Anton
authors.initials: A
authors.lastname: Sculean
authors.forename: Dieter D
authors.initials: DD
authors.lastname: Bosshardt
authors.forename: Daniel
authors.initials: D
authors.lastname: Buser
mesh_terms: D000818:Animals; D064592:Autografts / Q000378:metabolism / Q000601:surgery*; D055396:Bone Morphogenetic Protein 2 / Q000032:analysis; D001862:Bone Resorption / Q000378:metabolism; D016025:Bone Transplantation / Q000295:instrumentation*; D001842:Bone and Bones / Q000166:cytology* / Q000378:metabolism; D002452:Cell Count; D002454:Cell Differentiation / Q000502:physiology; D049109:Cell Proliferation; D002470:Cell Survival / Q000502:physiology; D002478:Cells, Cultured; D024042:Collagen Type I / Q000032:analysis; D050659:Core Binding Factor Alpha 1 Subunit / Q000032:analysis; D017077:Culture Media, Conditioned; D036341:Intercellular Signaling Peptides and Proteins / Q000378:metabolism*; D008934:Mitogens / Q000032:analysis; D010006:Osteoblasts / Q000502:physiology; D015675:Osteocalcin / Q000032:analysis; D010012:Osteogenesis / Q000502:physiology; D053244:Osteoprotegerin / Q000032:analysis; D010027:Osteotomy / Q000295:instrumentation; D059745:Piezosurgery / Q000379:methods; D053245:RANK Ligand / Q000032:analysis; D013552:Swine; D013556:Swine, Miniature; D020858:Tissue and Organ Harvesting / Q000295:instrumentation* / Q000379:methods; D053773:Transforming Growth Factor beta1 / Q000032:analysis; D042461:Vascular Endothelial Growth Factor A / Q000032:analysis
chemical_list: D055396:Bone Morphogenetic Protein 2; D024042:Collagen Type I; D050659:Core Binding Factor Alpha 1 Subunit; D017077:Culture Media, Conditioned; D036341:Intercellular Signaling Peptides and Proteins; D008934:Mitogens; D053244:Osteoprotegerin; D053245:RANK Ligand; D053773:Transforming Growth Factor beta1; D042461:Vascular Endothelial Growth Factor A; D015675:Osteocalcin