title: Healing patterns in calvarial bone defects following guided bone regeneration in rats. A micro-CT scan analysis.
abstract: OBJECTIVE
  The objective of this study was to evaluate healing patterns of critical-size calvarial bone defects treated according to principles of guided bone regeneration using micro-CT scan analysis. Specifically, the contribution of bone, periosteum and dura mater to the amount and mineralization of newly formed bone was evaluated.
  
  
  METHODS
  Surgically induced, critical-size calvarial bone defects in 48 adult male Wistar rats received the following: an occlusive expanded polytetrafluoroethylene (ePTFE) membrane at the exo- and endocranial aspect (OO; n = 12); an occlusive membrane at the exocranial and a perforated membrane at the endocranial aspect (OP; n = 12); a perforated membrane at the exocranial and an occlusive membrane at the endocranial aspect (PO; n = 12); and a perforated membrane at the exo- and endocranial aspect (PP; n = 12). The animals were euthanized at 4 weeks for quantitative analysis of bone volume fraction and mineralization in the region of interest (ROI) as well as in the external, middle and central area of the defect using micro-CT.
  
  
  RESULTS
  Bone volume fraction ranged from 31.4% (OP) to 24.5% (PP). No differences were found among the groups. Bone volume fraction and mineralization in the middle area were significantly greater in group OP than in group PP, and in the central area in group OO and PO than in group PP.
  
  
  CONCLUSIONS
  The results of this study suggest that use of occlusive ePTFE membranes enhances bone formation and maturation in the calvarial skeleton. When occlusion of endo- and exocranial tissues was compromised by membrane perforation, impaired bone formation and mineralization were observed.
authors.affiliation: Department of Orthodontics, Royal Dental College, Faculty of Health Sciences, Aarhus University, Aarhus, Denmark. cverna@odont.au.dk
authors.forename: Carlalberta
authors.initials: C
authors.lastname: Verna
authors.forename: Michel
authors.initials: M
authors.lastname: Dalstra
authors.forename: Ulf M E
authors.initials: UM
authors.lastname: Wikesjö
authors.forename: Leonardo
authors.initials: L
authors.lastname: Trombelli
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D001861:Bone Regeneration; D002113:Calcification, Physiologic; D004388:Dura Mater / Q000502:physiology; D048091:Guided Tissue Regeneration / Q000379:methods*; D008297:Male; D008567:Membranes, Artificial; D010521:Periosteum / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D012886:Skull / Q000000981:diagnostic imaging / Q000601:surgery; D014057:Tomography, X-Ray Computed / Q000379:methods; D014945:Wound Healing / Q000502:physiology*
chemical_list: D008567:Membranes, Artificial