title: Influence of rhBMP-2 on bone formation and osseointegration in different implant systems after sinus-floor elevation. An in vivo study on sheep.
abstract: BACKGROUND
  Several studies have reported certain bone morphogenic proteins (BMPs) to have positive effects on bone generation. Although some investigators have studied the effects of human recombinant BMP (rhBMP-2) in sinus augmentation in sheep, none of these studies looked at the placement of implants at the time of sinus augmentation. Furthermore, no literature could be found to report on the impact that different implant systems, as well as the positioning of the implants had on bone formation if rhBMP-2 was utilized in sinus-lift procedures.
  
  
  OBJECTIVE
  The aim of this study was to compare sinus augmentation with rhBMP-2 on a poly-d, l-lactic-co-glycolic acid gelatine (PLPG) sponge with sinus augmentation with autologous pelvic cancellous bone in the maxillary sinus during the placement of different dental implants.
  
  
  METHODS
  Nine adult female sheep were submitted to bilateral sinus-floor elevation. In one side (test group) the sinus lift was performed with rhBMP-2 on a PLPG-sponge, while the contralateral side served as the control by using cancellous bone from the iliac crest. Three different implants (Bränemark(®), 3i(®) and Straumann(®)) were inserted either simultaneously with the sinus augmentation or as a two staged procedure 6 weeks later. The animals were sacrificed at 6 and 12 weeks for histological and histomorphometrical evaluations during which bone-to-implant contact (BIC) and bone density (BD) were evaluated.
  
  
  RESULTS
  BD and BIC were significantly higher at 12 weeks in the test group if the implants were placed at the time of the sinus lift (p<0.05). No difference was observed between the different implant systems or positions.
  
  
  CONCLUSIONS
  The use of rhBMP-2 with PLPG-sponge increased BIC as well as BD in the augmented sinuses if compared to autologous bone. Different implant systems and positions of the implants had no effect on BIC or BD.
authors.affiliation: Department of Oral and Maxillofacial Surgery, University of Freiburg, Germany.
authors.forename: Ralf
authors.initials: R
authors.lastname: Gutwald
authors.forename: Jörg
authors.initials: J
authors.lastname: Haberstroh
authors.forename: Andres
authors.initials: A
authors.lastname: Stricker
authors.forename: Eva
authors.initials: E
authors.lastname: Rüther
authors.forename: Florian
authors.initials: F
authors.lastname: Otto
authors.forename: Samuel Porfirio
authors.initials: SP
authors.lastname: Xavier
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Oshima
authors.forename: E
authors.initials: E
authors.lastname: Marukawa
authors.forename: I
authors.initials: I
authors.lastname: Seto
authors.forename: S
authors.initials: S
authors.lastname: Enomoto
authors.forename: Christiaan F
authors.initials: CF
authors.lastname: Hoogendijk
authors.forename: Rainer
authors.initials: R
authors.lastname: Schmelzeisen
authors.forename: Sebastian
authors.initials: S
authors.lastname: Sauerbier
mesh_terms: D020341:Absorbable Implants; D000540:Alveolar Ridge Augmentation / Q000379:methods*; D000818:Animals; D015519:Bone Density / Q000187:drug effects*; D055396:Bone Morphogenetic Protein 2 / Q000008:administration & dosage / Q000494:pharmacology*; D016025:Bone Transplantation; D015921:Dental Implants; D017267:Dental Prosthesis Design; D019094:Dental Prosthesis, Implant-Supported; D004195:Disease Models, Animal; D016503:Drug Delivery Systems; D005260:Female; D005781:Gelatin Sponge, Absorbable; D006801:Humans; D008443:Maxillary Sinus / Q000601:surgery; D013516:Oral Surgical Procedures, Preprosthetic / Q000379:methods; D016348:Osseointegration / Q000187:drug effects*; D010012:Osteogenesis / Q000187:drug effects; D011994:Recombinant Proteins; D012756:Sheep
chemical_list: C525718:BMP2 protein, human; D055396:Bone Morphogenetic Protein 2; D015921:Dental Implants; D011994:Recombinant Proteins