title: De novo bone formation underneath the sinus membrane supported by a bone patch: a pilot experiment in rabbit sinus model.
abstract: OBJECTIVE
  The objectives of this study were to evaluate bone regeneration beneath a newly devised bone substitute combined with collagen membrane (called a bone patch) lying over a concomitantly placed mini-implant following sinus floor elevation and verify its usefulness as a carrier system for recombinant human bone morphogenetic protein-2 (rhBMP-2) in rabbits.
  
  
  METHODS
  The sinus floor elevation procedure was performed bilaterally in five rabbits. Either a plain bone patch (control group) or an rhBMP-2-loaded patch (experimental group) was randomly placed beneath the elevated sinus membrane (SM) of both sinuses, where the mini-implants were concomitantly placed. Micro-computed tomographic and histologic analyses were performed at 4 weeks post-surgery.
  
  
  RESULTS
  In micro-computed tomography, the median values of the total augmented volume and the mineralized bone volume were significantly higher in the experimental group than in the control group (161 vs. 122 mm3[P < 0.01] and 48 vs. 42 mm3[P < 0.05], respectively). Histometric analysis revealed the same outcomes, with new bone areas of 6.41 and 2.97 mm2in the experimental and control groups, respectively (P < 0.001), and bone-to-implant contact ratios of 22.6% and 5.2%, respectively (P < 0.001).
  
  
  CONCLUSIONS
  The newly devised bone patch in this study can support the elevated SM and facilitate bone regeneration from the basal bone with a reduced amount of biomaterial. The addition of rhBMP-2 may shorten the healing time for multidirectional bone regeneration toward the implant.
authors.affiliation: Department of Periodontology, Research Institute for Periodontal Regeneration, College of Dentistry, Yonsei University, Seoul, Republic of Korea.
authors.forename: So-Ra
authors.initials: SR
authors.lastname: Yoon
authors.affiliation: Department of Periodontology, Research Institute for Periodontal Regeneration, College of Dentistry, Yonsei University, Seoul, Republic of Korea.
authors.forename: Jae-Kook
authors.initials: JK
authors.lastname: Cha
authors.affiliation: Department of Periodontology, School of Dentistry, Kyung Hee University, Seoul, Republic of Korea.
authors.forename: Hyun-Chang
authors.initials: HC
authors.lastname: Lim
authors.affiliation: Department of Periodontology, Research Institute for Periodontal Regeneration, College of Dentistry, Yonsei University, Seoul, Republic of Korea.
authors.forename: Jung-Seok
authors.initials: JS
authors.lastname: Lee
authors.affiliation: Department of Periodontology, Research Institute for Periodontal Regeneration, College of Dentistry, Yonsei University, Seoul, Republic of Korea.
authors.forename: Seong-Ho
authors.initials: SH
authors.lastname: Choi
authors.affiliation: Department of Periodontology, Research Institute for Periodontal Regeneration, College of Dentistry, Yonsei University, Seoul, Republic of Korea.
authors.forename: Ui-Won
authors.initials: UW
authors.lastname: Jung
mesh_terms: D000818:Animals; D001861:Bone Regeneration; D018786:Bone Substitutes; D003094:Collagen; D008297:Male; D008567:Membranes, Artificial; D023421:Models, Animal; D010012:Osteogenesis; D011817:Rabbits; D059546:Sinus Floor Augmentation
chemical_list: D018786:Bone Substitutes; D008567:Membranes, Artificial; D003094:Collagen
keywords: animal study; bone morphogenetic protein-2; bone regeneration; collagen; dental implant; histology; maxillary sinus; micro-computed tomography