title: Bone Regeneration with Bilayer Bone Augmentation Technique for the Treatment of Dehiscence-Type Defects Around Implants: A Preliminary Study in Dogs.
abstract: OBJECTIVE
  The purpose of this study was to histomorphometrically compare the effects of the bilayer bone augmentation technique for the treatment of dehiscence-type defects around implants and evaluate the role as a membrane of the xenogeneic bone positioned as the outer layer in the bilayer bone augmentation technique.
  
  
  METHODS
  Four standardized dehiscence defects measuring 5 mm in height from the crestal bone, 3 mm in width mesiodistally, and 4 mm in depth from the surface of the buccal bone were prepared on each mandible unilaterally in three dogs, and one implant was placed per defect, where each defect was treated with autograft, xenograft, the bilayer bone augmentation technique, or negative control without a membrane. The animals were sacrificed after an 8-week healing interval for histomorphometric analyses. The measurements of newly formed bone height, newly formed bone height contacting the implant, newly formed bone area, and the width of newly formed bone were made using incandescent and polarized light microscopy.
  
  
  RESULTS
  Bone height and newly formed bone height contacting the implant in the autograft group were higher than in the xenograft, bilayer bone augmentation, and control groups. Newly formed bone area in the bilayer bone augmentation and autograft groups was higher than in the xenograft and control groups. The width of newly formed bone at 4.5 mm apically from the implant shoulder was greater in the xenograft and bilayer bone augmentation groups than in the control and autograft groups. However, the differences between the groups in bone height, newly formed bone height contacting the implant, newly formed bone area, and width of newly formed bone were not statistically significant in the histomorphometric examinations (P < .05). Data were verified with the Kruskal-Wallis test.
  
  
  CONCLUSIONS
  The results of this study show the osteogenic effect of autogenous bone and the effect of mechanical support for prolonged space maintenance of xenogeneic bone for the treatment of dehiscence-type defects around implants. Further studies with a larger sample size are needed to confirm the efficacy of the bilayer bone augmentation technique.
authors.forename: Dae-Jong
authors.initials: DJ
authors.lastname: You
authors.forename: Hyun-Joong
authors.initials: HJ
authors.lastname: Yoon
mesh_terms: D000540:Alveolar Ridge Augmentation / Q000379:methods*; D000818:Animals; D064592:Autografts / Q000637:transplantation; D001861:Bone Regeneration / Q000502:physiology*; D016025:Bone Transplantation / Q000379:methods*; D003758:Dental Implantation, Endosseous / Q000379:methods; D015921:Dental Implants; D004285:Dogs; D064593:Heterografts / Q000637:transplantation; D008334:Mandible / Q000473:pathology / Q000601:surgery; D008336:Mandibular Diseases / Q000473:pathology / Q000601:surgery; D010012:Osteogenesis / Q000502:physiology; D013529:Surgical Wound Dehiscence / Q000601:surgery*; D013997:Time Factors; D020390:Tooth Socket / Q000473:pathology / Q000601:surgery; D014945:Wound Healing / Q000502:physiology
chemical_list: D015921:Dental Implants