title: Bone augmentation at peri-implant dehiscence defects comparing a synthetic polyethylene glycol hydrogel matrix vs. standard guided bone regeneration techniques.
abstract: OBJECTIVE
  The aim of the study was to test whether or not the use of a polyethylene glycol (PEG) hydrogel with or without the addition of an arginylglycylaspartic acid (RGD) sequence applied as a matrix in combination with hydroxyapatite/tricalciumphosphate (HA/TCP) results in similar peri-implant bone regeneration as traditional guided bone regeneration procedures.
  
  
  METHODS
  In 12 beagle dogs, implant placement and peri-implant bone regeneration were performed 2 months after tooth extraction in the maxilla. Two standardized box-shaped defects were bilaterally created, and dental implants were placed in the center of the defects with a dehiscence of 4 mm. Four treatment modalities were randomly applied: i)HA/TCP mixed with a synthetic PEG hydrogel, ii)HA/TCP mixed with a synthetic PEG hydrogel supplemented with an RGD sequence, iii)HA/TCP covered with a native collagen membrane (CM), iv)and no bone augmentation (empty). After a healing period of 8 or 16 weeks, micro-CT and histological analyses were performed.
  
  
  RESULTS
  Histomorphometric analysis revealed a greater relative augmented area for groups with bone augmentation (43.3%-53.9% at 8 weeks, 31.2%-42.8% at 16 weeks) compared to empty controls (22.9% at 8 weeks, 1.1% at 16 weeks). The median amount of newly formed bone was greatest in group CM at both time-points. Regarding the first bone-to-implant contact, CM was statistically significantly superior to all other groups at 8 weeks.
  
  
  CONCLUSIONS
  Bone can partially be regenerated at peri-implant buccal dehiscence defects using traditional guided bone regeneration techniques. The use of a PEG hydrogel applied as a matrix mixed with a synthetic bone substitute material might lack a sufficient stability over time for this kind of defect.
authors.affiliation: Clinic of Fixed and Removable Prosthodontics and Dental Material Science, University of Zurich, Zurich, Switzerland.
authors.forename: Daniel S
authors.initials: DS
authors.lastname: Thoma
authors.affiliation: Department of Periodontology, Research Institute for Periodontal Regeneration, College of Dentistry, Yonsei University, Seoul, South Korea.
authors.forename: Ui-Won
authors.initials: UW
authors.lastname: Jung
authors.affiliation: Department of Periodontology, Research Institute for Periodontal Regeneration, College of Dentistry, Yonsei University, Seoul, South Korea.
authors.forename: Jin-Young
authors.initials: JY
authors.lastname: Park
authors.affiliation: Clinic of Fixed and Removable Prosthodontics and Dental Material Science, University of Zurich, Zurich, Switzerland.
authors.forename: Stefan P
authors.initials: SP
authors.lastname: Bienz
authors.affiliation: Clinic of Fixed and Removable Prosthodontics and Dental Material Science, University of Zurich, Zurich, Switzerland.
authors.forename: Jürg
authors.initials: J
authors.lastname: Hüsler
authors.affiliation: Clinic of Fixed and Removable Prosthodontics and Dental Material Science, University of Zurich, Zurich, Switzerland.
authors.forename: Ronald E
authors.initials: RE
authors.lastname: Jung
mesh_terms: D000818:Animals; D001861:Bone Regeneration / Q000187:drug effects*; D018786:Bone Substitutes / Q000494:pharmacology; D002130:Calcium Phosphates / Q000494:pharmacology*; D003094:Collagen / Q000494:pharmacology; D015921:Dental Implants; D004285:Dogs; D017886:Durapatite / Q000494:pharmacology*; D016557:Guided Tissue Regeneration, Periodontal / Q000379:methods*; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate / Q000494:pharmacology*; D008437:Maxilla / Q000000981:diagnostic imaging / Q000601:surgery; D009842:Oligopeptides / Q000494:pharmacology*; D013529:Surgical Wound Dehiscence / Q000188:drug therapy*; D014945:Wound Healing / Q000187:drug effects; D055114:X-Ray Microtomography
chemical_list: D018786:Bone Substitutes; D002130:Calcium Phosphates; D015921:Dental Implants; D009842:Oligopeptides; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D003094:Collagen; D017886:Durapatite; C049554:glycyl-arginyl-glycyl-aspartyl-serine; C018392:tricalcium phosphate
keywords: animal research; bone; bone regeneration; bone substitutes; dental implants; guided tissue regeneration; polyethylene glycols