title: Resorption of deproteinized bovine bone mineral in a porcine calvaria augmentation model.
abstract: OBJECTIVE
  The original aim of the study was to determine the osteoconductive capacity of deproteinized bovine bone mineral (DBBM) of different particle sizes underneath acrylic hemispheres in vivo. However, the model failed and allowed us to report on the resorption of DBBM.
  
  
  METHODS
  Acrylic hemispheres were filled with and without a DBBM at a small particle size of 125-250 μm and at the regular particle size of 250-1000 μm. The hemispheres were positioned on the calvaria of eight minipigs. Histological and histomorphometric analysis was performed after 12 weeks.
  
  
  RESULTS
  We found that the acrylic hemispheres were displaced and a dense fibrous capsule sequestered the augmented area. Histology showed severe resorption activity and the presence of multinucleated cells on the surface of DBBM particles in areas adjacent to the fibrous capsule. Histomorphometric analysis revealed that only less than half of the originally augmented area, which was approximately 30 mm(2) , remained after 12 weeks. The amount of residual DBBM (median 0.9 and 3.49 mm(2)) and bone (median 7.22 and 7.51 mm(2)) in the augmented area was similar in the small and the regular particle size group.
  
  
  CONCLUSIONS
  The model represents a pathologic situation of excess resorption of DBBM and bone in an augmented area. The underlying cellular mechanisms remain to be uncovered.
authors.affiliation: Department of Oral Surgery, Medical University of Vienna, Vienna, Austria.
authors.forename: Dieter
authors.initials: D
authors.lastname: Busenlechner
authors.forename: Stefan
authors.initials: S
authors.lastname: Tangl
authors.forename: Christoph
authors.initials: C
authors.lastname: Arnhart
authors.forename: Heinz
authors.initials: H
authors.lastname: Redl
authors.forename: Christian
authors.initials: C
authors.lastname: Schuh
authors.forename: Georg
authors.initials: G
authors.lastname: Watzek
authors.forename: Reinhard
authors.initials: R
authors.lastname: Gruber
mesh_terms: D000818:Animals; D001861:Bone Regeneration; D001862:Bone Resorption; D018786:Bone Substitutes / Q000494:pharmacology*; D002417:Cattle; D008903:Minerals / Q000494:pharmacology*; D010316:Particle Size; D012886:Skull / Q000601:surgery*; D013552:Swine
chemical_list: C077540:Bio-Oss; D018786:Bone Substitutes; D008903:Minerals