title: Hydroxyapatite and collagen combination-coated dental implants display better bone formation in the peri-implant area than the same combination plus bone morphogenetic protein-2-coated implants, hydroxyapatite only coated implants, and uncoated implants.
abstract: OBJECTIVE
  The objective of this study was to compare peri-implant bone formation among uncoated (UC), hydroxyapatite (HA), collagen plus HA (CH), and collagen, HA, plus bone morphogenetic protein-2 (BMP-2) implant groups.
  
  
  METHODS
  Implants in the UC group had acid-etched surfaces. The surface coating was applied using the aerosol deposition method. The coated surfaces were examined by scanning electron microscopy, x-ray diffraction (XRD), and Fourier-transformed infrared absorption analysis. Subsequently, 6 implants from each group (total, 24 implants) were installed in the tibias of rabbits. The animals were sacrificed at 6 weeks after implant installation. Peri-implant bone formation and bone-to-implant contact (BIC) were measured in histologic sections. Significant differences among groups were evaluated using analysis of variance.
  
  
  RESULTS
  Based on the measured XRD patterns, there was a characteristic HA phase (International Centre for Diffraction Data [ICDD], 086-0740) coated on the titanium (ICDD, 089-3725). Subsequent coating processes for collagen and BMP-2 did not display additional diffraction peaks, but maintained the diffraction patterns of the HA-coated titanium. The presence of collagen was verified by infrared absorption analysis. When comparing these modifications with UC surfaces, only the CH coating displayed significantly greater peri-implant bone formation and BIC (P = .003 and P < .001, respectively). Adding BMP-2 to the implant surface did not produce any advantage compared with the CH coating.
  
  
  CONCLUSIONS
  In this study, the CH group displayed significantly greater new bone formation and BIC than the other groups. There was no significant difference among the other groups.
authors: Fellow, Department of Oral and Maxillofacial Surgery, College of Dentistry, Gangneung-Wonju National University, Gangneung, Korea.
authors: Sang-Woon
authors: SW
authors: Lee
authors: Researcher, Functional Materials Division, Korea Institute of Materials Science, Changwon, Korea.
authors: Byung-Dong
authors: BD
authors: Hahn
authors: Researcher, Gangneung Center, Korea Basic Science Institute, Gangneung, Korea.
authors: Tae Yeon
authors: TY
authors: Kang
authors: Researcher, Gangneung Center, Korea Basic Science Institute, Gangneung, Korea.
authors: Myung-Jin
authors: MJ
authors: Lee
authors: Professor, School of Biochemistry and Cell Biology, WCU Project, Skeletal Diseases Genome Research Center, Kyungpook National University, Daegu, Korea.
authors: Je-Yong
authors: JY
authors: Choi
authors: Assistant Professor, Department of Oral and Maxillofacial Surgery, College of Dentistry, Gangneung-Wonju National University, Gangneung, Korea.
authors: Min-Keun
authors: MK
authors: Kim
authors: Associate Professor, Department of Oral and Maxillofacial Surgery, College of Dentistry, Gangneung-Wonju National University, Gangneung, Korea. Electronic address: epker@chol.com.
authors: Seong-Gon
authors: SG
authors: Kim
mesh_terms: D000134:Acid Etching, Dental / Q000379:methods; D000336:Aerosols; D000818:Animals; D055396:Bone Morphogenetic Protein 2 / Q000737:chemistry*; D020099:Coated Materials, Biocompatible / Q000737:chemistry*; D024042:Collagen Type I / Q000737:chemistry*; D015921:Dental Implants; D003764:Dental Materials / Q000737:chemistry; D017267:Dental Prosthesis Design; D017886:Durapatite / Q000737:chemistry*; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D016348:Osseointegration / Q000502:physiology; D010012:Osteogenesis / Q000502:physiology*; D011817:Rabbits; D017550:Spectroscopy, Fourier Transform Infrared; D013499:Surface Properties; D013977:Tibia / Q000473:pathology / Q000601:surgery; D014025:Titanium / Q000737:chemistry; D014961:X-Ray Diffraction
chemical_list: D000336:Aerosols; C525718:BMP2 protein, human; D055396:Bone Morphogenetic Protein 2; D020099:Coated Materials, Biocompatible; D024042:Collagen Type I; D015921:Dental Implants; D003764:Dental Materials; D017886:Durapatite; D014025:Titanium