title: Morphometric evaluation of the repair of critical-size defects using demineralized bovine bone and autogenous bone grafts in rat calvaria.
abstract: OBJECTIVE
  To evaluate the repair of critical-size bone defects in rats treated with demineralized bovine bone (DBB) compared with autogenous bone (AB).
  
  
  METHODS
  A bone defect of 8 mm in diameter was created in the calvaria of 50 Rattus norvegicus, treated either with DBB or AB. Sub-groups of five rats of each group were killed at 7, 14, 21, 30 and 90 days post-operatively, and the skulls were removed and processed histologically. Histological sections were stained with hematoxylin and eosin.
  
  
  RESULTS
  Histological analysis showed complete closure of the defects with new bone at 90 days in group AB, and substitution of the biomaterial by fibrotic connective tissue in the DBB group at 21 days. Morphometric analysis showed that DBB was rapidly absorbed at 14 days, with its volume density decreasing from 47%+/-0.8% at 7 days to 1.2%+/-0.41% at 14 days. Subsequently, volume densities of the connective tissue and neoformed bone increased from 51.1%+/-11.17% to 86.8%+/-7.92% and from 1.9%+/-1.13% to 12%+/-8.02%, respectively, for the same time interval. The volume density of AB particles did not change throughout the experimental periods, but the amount of new bone increased markedly between 7 and 90 days, from 4.5%+/-1.57% to 53.5%+/-6.42% (P<0.05).
  
  
  CONCLUSIONS
  DBB did not provide complete repair of the defects, with significantly less new bone formation than in the AB group.
authors: Institute of Biology, UNICAMP, Bauru Dental School, University of São Paulo, Brazil.
authors: Rodrigo Cardoso
authors: RC
authors: de Oliveira
authors: Fabio Henrique Gelonese
authors: FH
authors: de Oliveira
authors: Tânia Mary
authors: TM
authors: Cestari
authors: Rumio
authors: R
authors: Taga
authors: José Mauro
authors: JM
authors: Granjeiro
mesh_terms: D020341:Absorbable Implants; D000818:Animals; D001672:Biocompatible Materials / Q000627:therapeutic use; D001857:Bone Matrix / Q000502:physiology*; D001861:Bone Regeneration / Q000187:drug effects*; D018786:Bone Substitutes / Q000627:therapeutic use*; D016025:Bone Transplantation / Q000379:methods*; D002417:Cattle; D003399:Craniotomy / Q000379:methods; D008297:Male; D010012:Osteogenesis / Q000187:drug effects / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D012886:Skull / Q000187:drug effects / Q000502:physiology / Q000601:surgery*; D013997:Time Factors
chemical_list: D001672:Biocompatible Materials; D018786:Bone Substitutes