title: Influence of space-filling materials in subantral bone augmentation: blood clot vs. autogenous bone chips vs. bovine hydroxyapatite.
abstract: OBJECTIVE
  The first objective of the present study was to compare the short- and long-term 3D volume stability of sub-sinusal bone regeneration in rabbits using different space fillers. The second objective was to assess qualitatively and quantitatively the early bone formation process and long-term behavior of the regenerated bone.
  
  
  METHODS
  Fifteen rabbits underwent a double sinus lift procedure using: blood clot (Clot), autogenous bone chips (Auto) and bovine hydroxyapatite (BHA). Animals were euthanized at 1 week, 5 weeks and 6 months. Samples were subjected to X-ray microtomography and histology. Variations in the volume of bone augmentations were calculated at different time points. Qualitative analysis was performed using 7 μm sections and quantitative histomorphometric analyses were carried out using scanning electron microscopy.
  
  
  RESULTS
  From baseline (100%) to 5 weeks, the augmented volumes declined to 17.3% (Clot), 57.6% (Auto) and 90.6% (BHA). After 6 months, only 19.4% (Clot) and 31.4% (Auto) of initial volumes were found, while it remained more stable in the BHA group (84%). At 1 week, an initial osteogenesis process could be observed in the three groups along the bone walls. At 5 weeks, despite a significant decline in the volume, newly formed bone density was higher with Clot and Auto than with BHA. At 6 months, bone densities were statistically similar in the three groups. However, after 6 months, the surface invaded by newly formed bone (regenerated area) was significantly higher when BHA was used as space filler. In the BHA group, the biomaterial area slightly decreased from 42.7% (1 week) to 40% (5 weeks) and 34.9% (6 months) and the density of the composite regenerated tissue (bone+BHA) reached >50% at 6 months.
  
  
  CONCLUSIONS
  The three space fillers allowed bone formation to occur. Nevertheless, augmented volumes declined in the Clot and Auto groups, while they remained stable with BHA. A slowly resorbable biomaterial might be suitable in sub-sinusal bone augmentation for preventing the re-expansion process and for augmenting the density of the regenerated tissues.
authors.affiliation: Department of Periodontology and Oral Surgery, Faculty of Medicine, University of Liege, Belgium. france.lambert@chu.ulg.ac.be
authors.forename: France
authors.initials: F
authors.lastname: Lambert
authors.forename: Angélique
authors.initials: A
authors.lastname: Léonard
authors.forename: Pierre
authors.initials: P
authors.lastname: Drion
authors.forename: Sophie
authors.initials: S
authors.lastname: Sourice
authors.forename: Pierre
authors.initials: P
authors.lastname: Layrolle
authors.forename: Eric
authors.initials: E
authors.lastname: Rompen
mesh_terms: D020341:Absorbable Implants; D000540:Alveolar Ridge Augmentation / Q000379:methods*; D000818:Animals; D001672:Biocompatible Materials / Q000627:therapeutic use*; D001777:Blood Coagulation; D015519:Bone Density / Q000502:physiology; D001861:Bone Regeneration / Q000502:physiology; D016723:Bone Remodeling / Q000502:physiology; D001862:Bone Resorption / Q000473:pathology; D018786:Bone Substitutes / Q000627:therapeutic use*; D016025:Bone Transplantation / Q000502:physiology*; D002417:Cattle; D054893:Cone-Beam Computed Tomography; D017886:Durapatite / Q000627:therapeutic use*; D021621:Imaging, Three-Dimensional; D008297:Male; D008437:Maxilla / Q000473:pathology / Q000601:surgery*; D008443:Maxillary Sinus / Q000473:pathology / Q000601:surgery*; D008855:Microscopy, Electron, Scanning; D008903:Minerals / Q000627:therapeutic use; D010006:Osteoblasts / Q000473:pathology; D010010:Osteoclasts / Q000473:pathology; D010012:Osteogenesis / Q000502:physiology; D011817:Rabbits; D013997:Time Factors; D014182:Transplantation, Autologous; D055114:X-Ray Microtomography
chemical_list: C077540:Bio-Oss; D001672:Biocompatible Materials; D018786:Bone Substitutes; D008903:Minerals; D017886:Durapatite