title: Effect of recombinant human bone morphogenetic protein-2 on the osseointegration of dental implants: a biomechanics study.
abstract: BACKGROUND
  Bone augmentation procedures in combination with dental implants enhance osseointegration in areas that demonstrate localized bone deficit. Clinical confirmation of a biomechanically stable interface is essential for functional implant loading.
  
  
  OBJECTIVE
  The aim of this study was to evaluate biomechanically the effect of recombinant human bone morphogenetic protein (rhBMP)-2 on implant osseointegration and correlate it with periotest and radiographic measurements.
  
  
  METHODS
  Hollow cylinder implants were filled with absorbable collagen sponge soaked with rhBMP-2 or left empty and implanted in dog mandibles. The animals were followed for 4, 8, and 12 weeks, periotest assessment was performed at the end of each time interval, and specimens were collected for pullout biomechanical testing and radiographic evaluation of bone-implant contact levels.
  
  
  RESULTS
  Periotest assessment did not provide evidence of statistically significant differences between the two groups and correlated well with the radiographic bone-implant contact levels. The pullout test revealed a higher correlation between force/displacement and displacement/energy for the experimental group, suggesting that the addition of rhBMP-2 did influence the rate of osseointegration.
  
  
  CONCLUSIONS
  The results from the pullout test support the potential role of rhBMP-2 in clinical applications by promoting a biomechanically mature interface at 12 weeks. However, radiographic and periotest assessment of the bone-implant interface did not provide evidence of the differences observed with biomechanical testing.
authors.affiliation: Department of Fixed Prosthodontics, Dental School, Athens University, Athens, Greece. nsykaras@otenet.gr
authors.forename: Nikitas
authors.initials: N
authors.lastname: Sykaras
authors.forename: Anthony M
authors.initials: AM
authors.lastname: Iacopino
authors.forename: Robert G
authors.initials: RG
authors.lastname: Triplett
authors.forename: Victoria A
authors.initials: VA
authors.lastname: Marker
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins / Q000494:pharmacology*; D015921:Dental Implants; D017267:Dental Prosthesis Design; D004285:Dogs; D004337:Drug Carriers; D005781:Gelatin Sponge, Absorbable; D006801:Humans; D008297:Male; D008334:Mandible / Q000000981:diagnostic imaging / Q000187:drug effects / Q000601:surgery; D016348:Osseointegration / Q000187:drug effects*; D010027:Osteotomy; D011859:Radiography; D011994:Recombinant Proteins; D013314:Stress, Mechanical; D013499:Surface Properties; D013524:Surgical Flaps; D013997:Time Factors; D016212:Transforming Growth Factor beta / Q000494:pharmacology*
chemical_list: C525718:BMP2 protein, human; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins; D015921:Dental Implants; D004337:Drug Carriers; D011994:Recombinant Proteins; D016212:Transforming Growth Factor beta; C499469:recombinant human bone morphogenetic protein-2