title: Volumetric changes of the graft after maxillary sinus floor augmentation with Bio-Oss and autogenous bone in different ratios: a radiographic study in minipigs.
abstract: OBJECTIVE
  The objective of the present study was to learn about the volumetric changes of the graft after maxillary sinus floor augmentation with Bio-Oss and autogenous bone from the iliac crest or the mandible in different ratios in minipigs.
  
  
  METHODS
  Bilateral maxillary sinus floor augmentation was performed in 40 minipigs with: (A) 100% autogenous bone, (B) 75% autogenous bone and 25% Bio-Oss, (C) 50% autogenous bone and 50% Bio-Oss, (D) 25% autogenous bone and 75% Bio-Oss, and (E) 100% Bio-Oss. The autogenous bone graft was harvested from the iliac crest or the mandible and the graft composition was selected at random and placed concomitant with implant placement. Computed tomographies of the maxillary sinuses were obtained preoperatively, immediately postoperatively, and at euthanasia after 12 weeks. The volumetric changes of the graft were estimated using the Cavalieri principle and expressed as mean percentage with a 95% confidence interval (CI).
  
  
  RESULTS
  The mean volume of the graft was reduced by (A) 65% (95% CI: 60-70%), (B) 38% (95% CI: 35-41%), (C) 23% (95% CI: 21-25%), (D) 16% (95% CI: 12-21%), and (E) 6% (95% CI: 4-8%). The volumetric reduction was significantly influenced by the ratio of Bio-Oss and autogenous bone (P<0.001), but not by the origin of the autogenous bone graft (P=0.2).
  
  
  CONCLUSIONS
  The volume of autogenous bone grafts from the iliac crest and the mandible is reduced significantly after maxillary sinus floor augmentation in minipigs. The graft volume is better preserved after the addition of Bio-Oss and the volumetric reduction is significantly influenced by the ratio of Bio-Oss and autogenous bone. However, further studies are needed addressing the amount of new bone formation and bone-to-implant contact before the final conclusion can be made about the optimal ratio of Bio-Oss and autogenous bone.
authors: Department of Oral and Maxillofacial Surgery, Aalborg Hospital, Aarhus University Hospital, Aarhus, Denmark. marthom@mail.tele.dk
authors: Thomas
authors: T
authors: Jensen
authors: Søren
authors: S
authors: Schou
authors: Patricia A
authors: PA
authors: Svendsen
authors: Julie Lyng
authors: JL
authors: Forman
authors: Hans Jørgen G
authors: HJ
authors: Gundersen
authors: Hendrik
authors: H
authors: Terheyden
authors: Palle
authors: P
authors: Holmstrup
mesh_terms: D000818:Animals; D018786:Bone Substitutes / Q000494:pharmacology*; D016025:Bone Transplantation / Q000379:methods*; D003758:Dental Implantation, Endosseous / Q000379:methods*; D015921:Dental Implants; D005260:Female; D007085:Ilium / Q000637:transplantation*; D020007:Implants, Experimental; D008334:Mandible / Q000000981:diagnostic imaging / Q000637:transplantation*; D008443:Maxillary Sinus / Q000000981:diagnostic imaging / Q000601:surgery; D008903:Minerals / Q000494:pharmacology*; D011897:Random Allocation; D059546:Sinus Floor Augmentation / Q000379:methods*; D013552:Swine; D013556:Swine, Miniature; D014057:Tomography, X-Ray Computed; D016042:Transplantation, Heterotopic
chemical_list: C077540:Bio-Oss; D018786:Bone Substitutes; D015921:Dental Implants; D008903:Minerals