title: Osteoconductive effects of vinyl styrene microbeads in rat calvarial defects.
abstract: OBJECTIVE
  The aim of the present study was to evaluate the use of the nonresorbable vinyl styrene microbeads (VSM) alloplast as a delivery vehicle for platelet-derived growth factor (PDGF-BB) in rat calvarial critical size defects.
  
  
  METHODS
  Seventy-three Long-Evans male rats were divided into 4 groups; a negative control, vinyl styrene microbeads (VSM), PDGF-BB, and VSM plus PDGF-BB. Critical size calvarial defects were carried out and isolated with membranes sandwiching the defects with their fillers. Animals were sacrificed after 2, 4, and 16 weeks classifying each group into 3 subgroups. Calvarial specimens were radiographed for evaluation of regenerated bone volume and densitometry histogram analysis. Specimens were divided mid-sagittally and stained with hematoxylin and eosin (H&E) and trichrome stain for qualitative and histomorphometric analysis using an image analysis software.
  
  
  RESULTS
  The VSM groups showed statistically higher defect fills than the VSM-free groups at all sacrifice times except for the VSM/PDGF group that showed this difference after 2 weeks in relation to the PDGF group and the negative control after 4 and 16 weeks. For the radiographic analysis, the VSM/PDGF group showed the lowest bone volume compared with the other groups except when it was compared with the 4 weeks VSM group. In contrast, the PDGF showed the highest bone volumes at all sacrifice times that were only significant when compared with the 4 weeks VSM group and the 4 and 16 weeks VSM/PDGF group.
  
  
  CONCLUSIONS
  VSM enhances bone defect fill whereas the VSM/PDGF-BB is not able to improve bone regeneration capacity when compared with VSM alone.
authors.affiliation: Faculty of Dental Medicine, Al-Azhar University, Assiut, Egypt. kmarzouk1@gmail.com
authors.forename: Khalid Mohamed
authors.initials: KM
authors.lastname: Marzouk
authors.forename: Ahmed Y
authors.initials: AY
authors.lastname: Gamal
authors.forename: Akram A
authors.initials: AA
authors.lastname: Al-Awady
authors.forename: Mohamed M
authors.initials: MM
authors.lastname: Sharawy
mesh_terms: D000818:Animals; D000077214:Becaplermin; D001672:Biocompatible Materials / Q000494:pharmacology*; D001861:Bone Regeneration / Q000187:drug effects / Q000502:physiology*; D018786:Bone Substitutes / Q000494:pharmacology*; D004337:Drug Carriers; D016503:Drug Delivery Systems; D048091:Guided Tissue Regeneration / Q000379:methods; D008297:Male; D008863:Microspheres; D010982:Platelet-Derived Growth Factor / Q000008:administration & dosage / Q000502:physiology*; D020574:Proto-Oncogene Proteins c-sis; D051381:Rats; D020318:Rats, Long-Evans; D012886:Skull / Q000187:drug effects / Q000502:physiology* / Q000601:surgery; D020058:Styrene / Q000627:therapeutic use
chemical_list: D001672:Biocompatible Materials; D018786:Bone Substitutes; D004337:Drug Carriers; D010982:Platelet-Derived Growth Factor; D020574:Proto-Oncogene Proteins c-sis; D000077214:Becaplermin; D020058:Styrene