title: Healing of dehiscence-type defects in implants placed together with different barrier membranes: a comparative clinical study.
abstract: OBJECTIVE
  Premature exposure of membranes used in guided bone regeneration (GBR) results in decreased bone formation. The effect of an expanded polytetrafluoroethylene (e-PTFE) and two collagen membrane on bone healing of buccal dehiscence defects around implants in cases with and without premature membrane exposure was clinically evaluated.
  
  
  METHODS
  Three groups were established: Group OS (Ossix, n=73 implants, 41 patients), Group BG (Bio-Gide, n=53 implants, 28 patients) and Group GT (e-PTFE, Gore-Tex, n=34 implants, 17 patients). Defect height and width were measured at the time of implant placement and at second stage surgery. Surface area was calculated as half ellipses. When several implants were placed simultaneously, a mean of their defect width and height was calculated.
  
  
  RESULTS
  Mean percentage reduction of defect area (92.2+/-13.78% Group OS, 94.6+/-6.69% Group BG, and 97.3+/-4.91% Group GT) and height (81.6+/-23.19%, 85.4+/-12.26%, and 93.4+/-9.39% respectively) did not show statistically significant differences between groups. Differences between groups were not statistically significant for all parameters when cases without spontaneous membrane exposure were compared. However, differences were significant when spontaneous membrane exposure occurred. Mean percentage reduction of defect area among cases where membrane exposure occurred was 91.5+/-10.86% Group OS, 71.5+/-8.61% Group BG, and 73.7+/-13.97% Group GT. Mean percentage reduction of defect height among cases with membrane exposure was 76.4+/-18.28%, 53.4+/-9.86%, and 49.4+/-11.05%, respectively.
  
  
  CONCLUSIONS
  Premature exposure of membranes and subsequent and consequent exposure of implants results in impaired bone healing. Certain barrier membranes, as used in group OS, are apparently capable of supporting gingival healing even when prematurely exposed that could be advantageous in GBR procedures.
authors.affiliation: Dental and Maxillofacial Center, Tel-Aviv Medical Center, Tel-Aviv, Israel.
authors.forename: Ofer
authors.initials: O
authors.lastname: Moses
authors.forename: Sandu
authors.initials: S
authors.lastname: Pitaru
authors.forename: Zvi
authors.initials: Z
authors.lastname: Artzi
authors.forename: Carlos E
authors.initials: CE
authors.lastname: Nemcovsky
mesh_terms: D000704:Analysis of Variance; D001672:Biocompatible Materials / Q000627:therapeutic use; D001861:Bone Regeneration; D016009:Chi-Square Distribution; D003094:Collagen / Q000627:therapeutic use; D003758:Dental Implantation, Endosseous / Q000379:methods*; D015921:Dental Implants; D016557:Guided Tissue Regeneration, Periodontal / Q000379:methods*; D006801:Humans; D008567:Membranes, Artificial; D008875:Middle Aged; D011138:Polytetrafluoroethylene / Q000627:therapeutic use; D013529:Surgical Wound Dehiscence / Q000503:physiopathology*; D014945:Wound Healing / Q000502:physiology*
chemical_list: C106416:Bio-Gide; D001672:Biocompatible Materials; D015921:Dental Implants; D008567:Membranes, Artificial; D011138:Polytetrafluoroethylene; D003094:Collagen