title: Expanded vs. dense polytetrafluoroethylene membranes in vertical ridge augmentation around dental implants: a prospective randomized controlled clinical trial.
abstract: OBJECTIVE
  This prospective randomized controlled trial was designed to test the performance of titanium-reinforced dense polytetrafluoroethylene (d-PTFE) membrane vs. titanium-reinforced expanded polytetrafluoroethylene (e-PTFE) membrane in achieving vertical bone regeneration, both associated with a composite grafting material.
  
  
  METHODS
  The study enrolled 23 patients requiring bone augmentation with guided bone regeneration (GBR) procedures for placing implants in atrophic posterior mandibles (available bone height <7 mm). Implants were inserted and left to protrude from the bone level to achieve the programmed amount of vertical regeneration. Defects were filled with a composite bone graft (50% autologous bone and 50% mineralized bone allograft) and randomly covered with either an e-PTFE membrane (control) or a d-PTFE membrane (test). Membrane removal was performed after 6 months, and changes in bone height were recorded.
  
  
  RESULTS
  Seventy-eight implants were inserted in 26 mandibular sites contextually to vertical ridge augmentation procedures. The healing period was uneventful in all sites, and the vertical defects were satisfactorily filled with a newly formed hard tissue. Mean defect fill after 6 months was 5.49 mm (SD ± 1.58) at test sites and 4.91 mm (SD ± 1.78) at control sites. The normalized data (percentage changes against baseline) did not show any statistically significant difference between test and control groups (P = NS).
  
  
  CONCLUSIONS
  Based on the data from this study, both d-PTFE and e-PTFE membranes showed identical clinical results in the treatment of vertical bone defects around implants, using the GBR technique. The membrane removal procedure was easier to perform in the d-PTFE group than in the e-PTFE group.
authors.affiliation: Private Practice, Genova, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Ronda
authors.forename: Alberto
authors.initials: A
authors.lastname: Rebaudi
authors.forename: Lucio
authors.initials: L
authors.lastname: Torelli
authors.forename: Claudio
authors.initials: C
authors.lastname: Stacchi
mesh_terms: D000328:Adult; D000368:Aged; D000540:Alveolar Ridge Augmentation / Q000379:methods*; D001861:Bone Regeneration / Q000502:physiology*; D003758:Dental Implantation, Endosseous / Q000379:methods*; D015921:Dental Implants; D005260:Female; D016557:Guided Tissue Regeneration, Periodontal / Q000379:methods*; D006801:Humans; D008297:Male; D008334:Mandible / Q000601:surgery; D008567:Membranes, Artificial; D008875:Middle Aged; D011138:Polytetrafluoroethylene; D011446:Prospective Studies; D014025:Titanium; D016896:Treatment Outcome
chemical_list: D015921:Dental Implants; D008567:Membranes, Artificial; D011138:Polytetrafluoroethylene; D014025:Titanium
keywords: biomaterials; bone regeneration; clinical research; clinical trials; guided tissue regeneration