title: The effects of recombinant human bone morphogenetic protein-2-loaded tricalcium phosphate microsphere-hydrogel composite on the osseointegration of dental implants in minipigs.
abstract: Bone formation in tooth defect areas and the osseointegration of dental implants are very important for successful dental implant surgery. The aim of the present study was to assess the strengthening effect of a β-TCP microsphere-hydrogel composite containing recombinant human bone morphogenetic protein-2 (rhBMP-2) on bone healing and implant osseointegration. The molars and premolars on the left and right sides of the maxilla were extracted from six male minipigs, and dental implants were placed using either the β-TCP microsphere-hydrogel carrier alone or the carrier loaded with rhBMP-2 (500 μg). The animals were kept alive for a further 8 weeks. The molars and premolars from the left and the right sides of the mandibles of another six minipigs were extracted, and the animals were kept alive for 4 weeks. Two 5-mm-diameter bone defects were then made on both sides of the mandible. The defects were filled with saline, β-TCP microsphere-hydrogel carrier, or the carrier loaded with rhBMP-2 (300 μg), and dental implant fixtures were inserted. The animals were kept alive for a further 4 weeks. Bone formation was examined using plane radiographs, micro-CT, and the histology of undecalcified specimens. The group treated with the rhBMP-2-loaded carrier composite showed a significantly higher percentage bone volume and a greater trabecular thickness for the newly formed bone in the tooth defect areas when compared to the group treated with the carrier alone. The rhBMP-2 group had a significantly higher osseointegration, a larger percentage bone volume, greater trabecular thickness in the newly formed bone in tooth defect areas, a larger newly formed bone fraction in the fixture pitch, and a greater number of newly formed trabecular bones when compared to the other groups. We confirmed that the rhBMP-2-loaded carrier composite promotes new bone formation after tooth extraction and strengthens osseointegration of dental fixtures by improving the degree of osseointegration around the dental implant fixture.
authors.affiliation: Department of Orthopedic Surgery, College of Medicine, SMG-SNU Boramae Medical Center, Seoul National University, Seoul, Korea; Institute of Medical and Biological Engineering, Seoul National University Medical Research Center, Seoul, Korea.
authors.forename: Jae Hyup
authors.initials: JH
authors.lastname: Lee
authors.forename: Mi Young
authors.initials: MY
authors.lastname: Ryu
authors.forename: Hae-Ri
authors.initials: HR
authors.lastname: Baek
authors.forename: Hyun-Kyung
authors.initials: HK
authors.lastname: Lee
authors.forename: Jun-Hyuk
authors.initials: JH
authors.lastname: Seo
authors.forename: Kyung Mee
authors.initials: KM
authors.lastname: Lee
authors.forename: A-Young
authors.initials: AY
authors.lastname: Lee
authors.forename: Guang Bin
authors.initials: GB
authors.lastname: Zheng
authors.forename: Bong-Soon
authors.initials: BS
authors.lastname: Chang
authors.forename: Choon-Ki
authors.initials: CK
authors.lastname: Lee
mesh_terms: D000818:Animals; D055396:Bone Morphogenetic Protein 2 / Q000008:administration & dosage*; D002130:Calcium Phosphates / Q000008:administration & dosage; D003758:Dental Implantation, Endosseous / Q000379:methods*; D015921:Dental Implants; D006801:Humans; D020100:Hydrogels / Q000008:administration & dosage*; D008297:Male; D008863:Microspheres; D016348:Osseointegration / Q000187:drug effects*; D013552:Swine; D013556:Swine, Miniature
chemical_list: D055396:Bone Morphogenetic Protein 2; D002130:Calcium Phosphates; D015921:Dental Implants; D020100:Hydrogels; C018392:tricalcium phosphate
keywords: Bone defect; Dental implant; Hydrogel; Osseointegration; Recombinant human bone morphogenetic protein-2; β-tricalcium phosphate