title: Guided bone regeneration around dental implants in the atrophic alveolar ridge using a bioresorbable barrier. An experimental study in the monkey.
abstract: The aim of this study was to evaluate guided bone regeneration (GBR) around dental implants placed in atrophic alveolar ridges using an experimental, nonporous bioresorbable barrier. In 8 Rhesus monkeys, the maxillary canines and lateral incisors were extracted bilaterally and the remaining alveoli were reduced to create atrophic ridges. After a healing period of 3 months, soft tissue expansion was performed using a subperiosteal tissue expander. After 1 month of tissue expansion, and IMZ implant was placed in the atrophic ridge on each side in such a way that its coronal 4 mm to 5 mm remained circumferentially exposed above the bone level. The test implants were covered with a bioresorbable barrier made of poly (D,L-lactid-co-trimethylencarbonate) in a 70/30 ratio, whereas the control implants were covered with a nonresorbable expanded polytetrafluoroethylene (e-PTFE) barrier. The e-PTFE barriers were stabilized with titanium minipins while the bioresorbable barriers were analogously fixed using bioresorbable minipins made of poly (L-lactid-co-D,L-lactid) 70/30. Clinical healing progressed uneventfully in both groups and no soft tissue dehiscences occurred. Histometric and histomorphometric analyses were performed 5 months post surgery. Both test and control implants exhibited direct bone-to-implant contact to variable extents. The mean direct mineralized bone-to-implant contact length fraction was 32% of the total implant length in the test sites and 58% in the control sites. Control sites exhibited significantly greater bone fill compared to the experimental sites (P < 0.001). Histologic observations of test specimens demonstrated a moderate inflammatory reaction related to the degradation and resorption products of the barrier. In conclusion, the nonresorbable e-PTFE GBR barrier was found to be superior to the bioresorbable barriers tested in the present investigation.
authors.affiliation: Department of Prosthodontics, Albert-Ludwigs University, Freiburg, Germany.
authors.forename: M B
authors.initials: MB
authors.lastname: Hürzeler
authors.forename: C R
authors.initials: CR
authors.lastname: Quiñones
authors.forename: P
authors.initials: P
authors.lastname: Schüpbach
mesh_terms: D016301:Alveolar Bone Loss / Q000601:surgery*; D000818:Animals; D001672:Biocompatible Materials; D001673:Biodegradation, Environmental; D001861:Bone Regeneration; D003758:Dental Implantation, Endosseous; D015921:Dental Implants; D016557:Guided Tissue Regeneration, Periodontal / Q000379:methods*; D019344:Lactic Acid; D008253:Macaca mulatta; D008422:Materials Testing; D008437:Maxilla; D008567:Membranes, Artificial; D011100:Polyglycolic Acid; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011108:Polymers; D016062:Porosity
chemical_list: D001672:Biocompatible Materials; D015921:Dental Implants; D008567:Membranes, Artificial; D011108:Polymers; C065658:dimethyltrimethylene carbonate-trimethylene carbonate copolymer; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid