title: Comparison of bone morphogenetic protein-2 delivery systems to induce supracrestal bone guided by titanium implants in the rabbit mandible.
abstract: OBJECTIVE
  To compare the ability of three non-glycosylated/rhBMP-2 (BMP-2) delivery systems to induce supracrestal bone.
  
  
  METHODS
  Thirty-six custom SLActive dental implants were partially embedded in transverse orientation into the posterior mandibles of 18 adult rabbits with the head of the implant located 3 mm supracrestal. Delivery of BMP-2 (30 μg) from the following materials was studied: (1) Ti implant + BMP-2 with hydroxyapatite (HA)-coated collagen (Col/HA) scaffold, (2) Ti implant with Col/HA infused with PEG hydrogel + BMP-2, or (3) Ti implant with HA/β-TCP/PEG hydrogel scaffold + BMP-2. Scaffolds were secured with a metal "umbrella." Non-BMP-2 contralateral controls were included. MicroCT imaging and histological analysis was performed after 10 weeks to assess new supracrestal bone formation. In vitro BMP-2 release studies were conducted.
  
  
  RESULTS
  All treatment groups displayed new supracrestal bone formation. Ti + BMP-2 with Col/HA (3.0 ± 0.2 mm) and Ti with Col/HA/PEG hydrogel + BMP-2 (2.7 ± 0.4 mm) had significantly greater (P < 0.05) outcomes than without BMP-2. Maximum bone volume occurred in the Ti implant with HA/β-TCP/PEG hydrogel scaffold + BMP-2 group.
  
  
  CONCLUSIONS
  The use of an implant system composed of a partially inserted Ti implant, adjacent scaffold and scaffold stabilizer resulted in the formation of new supracrestal bone across all test groups with and without BMP-2. Delivery of BMP-2 directly from the Ti implant increased bone height, BIC and bone volume as compared to no BMP-2 when a Col/HA was used, but did not improve performance of the HA/β-TCP/PEG scaffold.
authors.affiliation: Department of Oral and Maxillofacial Surgery, Division of Implant Dentistry, Affiliated Stomatology Hospital of Medical School, Nanjing University, Nanjing, China.
authors.forename: Bo
authors.initials: B
authors.lastname: Wen
authors.affiliation: Department of Reconstructive Sciences, Center for Regeneration Medicine and Skeletal Development, School of Dental Medicine, University of Connecticut, Farmington, CT, USA.
authors.forename: Liisa
authors.initials: L
authors.lastname: Kuhn
authors.affiliation: Department of Reconstructive Sciences, Center for Regeneration Medicine and Skeletal Development, School of Dental Medicine, University of Connecticut, Farmington, CT, USA.
authors.forename: Lyndon
authors.initials: L
authors.lastname: Charles
authors.affiliation: Department of Reconstructive Sciences, Center for Regeneration Medicine and Skeletal Development, School of Dental Medicine, University of Connecticut, Farmington, CT, USA.
authors.forename: David
authors.initials: D
authors.lastname: Pendrys
authors.affiliation: Department of Craniofacial Sciences, Division of Oral and Maxillofacial Surgery, School of Dental Medicine, University of Connecticut, Farmington, CT, USA.
authors.forename: David
authors.initials: D
authors.lastname: Shafer
authors.affiliation: Department of Reconstructive Sciences, Center for Regeneration Medicine and Skeletal Development, School of Dental Medicine, University of Connecticut, Farmington, CT, USA.
authors.forename: Martin
authors.initials: M
authors.lastname: Freilich
mesh_terms: D000818:Animals; D055396:Bone Morphogenetic Protein 2 / Q000008:administration & dosage / Q000494:pharmacology*; D002130:Calcium Phosphates / Q000494:pharmacology; D003094:Collagen / Q000494:pharmacology; D015921:Dental Implants; D016503:Drug Delivery Systems; D017886:Durapatite / Q000494:pharmacology; D020100:Hydrogels / Q000494:pharmacology; D008334:Mandible / Q000601:surgery; D010012:Osteogenesis / Q000187:drug effects*; D011092:Polyethylene Glycols / Q000494:pharmacology; D011817:Rabbits; D054457:Tissue Scaffolds; D014025:Titanium; D055114:X-Ray Microtomography
chemical_list: C525718:BMP2 protein, human; D055396:Bone Morphogenetic Protein 2; D002130:Calcium Phosphates; D015921:Dental Implants; D020100:Hydrogels; C485817:beta-tricalcium phosphate; D011092:Polyethylene Glycols; D003094:Collagen; D017886:Durapatite; D014025:Titanium
keywords: BMP-2; biomaterial scaffold; dental implant; vertical supracrestal bone growth