title: In vitro and in vivo evaluation of e-PTFE and alkali-cellulose membranes for guided bone regeneration.
abstract: Guided bone regeneration (GBR) is employed to encourage the formation of new bone in osseous defects by restricting the infiltration of soft tissues. While a variety of membranes have been evaluated for this surgical procedure, the non-resorbable material of choice is currently expanded polytetrafluoroethylene (e-PTFE). A new alkali-cellulose membrane produced by a biotechnological process has been developed as an alternative to e-PTFE for GBR. In this study, the biocompatibility of this novel alkali-cellulose membrane and e-PTFE was compared using tissue culture and an in vivo GBR model. In vitro both materials supported the attachment, migration and differentiation of osteoblast-like cells in culture for up to 3 weeks. The in vivo model was based upon full-thickness transcortical bone defects in the mandibular rami of Sprague-Dawley rats. The right rami were used as controls, contralateral defects being covered bucally and lingually with either e-PTFE or alkali-cellulose membranes. Pathological and histomorphometric analysis was undertaken at 4 and 10 weeks post-implantation. Bone regeneration associated with alkali-cellulose membranes was predominantly endochondral in type in contrast to e-PTFE which induced direct bone formation (intramembranous ossification). The amount of new bone formed in defects was similar for both types of membrane, but alkali-cellulose membranes induced significantly greater inflammatory response; characterized by lymphocytes, macrophages and multinucleated giant cells. Degradation and possible exposure of individual cellulose fibres may account for the poor performance of alkali-cellulose membranes in vivo. This animal and in vitro study indicates that when choosing a non-resorbable membrane for GBR, e-PTFE membranes are likely to perform better than those produced from alkali-cellulose.
authors.affiliation: Centre for Biomaterials & Tissue Engineering, School of Clinical Dentistry, University of Sheffield, Sheffield S10 2TA, UK.
authors.forename: L A
authors.initials: LA
authors.lastname: Salata
authors.forename: P V
authors.initials: PV
authors.lastname: Hatton
authors.forename: A J
authors.initials: AJ
authors.lastname: Devlin
authors.forename: G T
authors.initials: GT
authors.lastname: Craig
authors.forename: I M
authors.initials: IM
authors.lastname: Brook
mesh_terms: D016301:Alveolar Bone Loss / Q000503:physiopathology / Q000601:surgery; D000704:Analysis of Variance; D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry; D001854:Bone Marrow Cells / Q000166:cytology; D001861:Bone Regeneration; D002448:Cell Adhesion; D002454:Cell Differentiation; D002465:Cell Movement; D002478:Cells, Cultured; D002482:Cellulose / Q000737:chemistry; D004195:Disease Models, Animal; D004867:Equipment Design; D015726:Giant Cells / Q000473:pathology; D016557:Guided Tissue Regeneration, Periodontal / Q000295:instrumentation*; D008214:Lymphocytes / Q000473:pathology; D008264:Macrophages / Q000473:pathology; D008334:Mandible / Q000503:physiopathology / Q000601:surgery; D008567:Membranes, Artificial; D010006:Osteoblasts / Q000166:cytology; D010012:Osteogenesis / Q000502:physiology; D011138:Polytetrafluoroethylene / Q000737:chemistry; D051381:Rats; D017207:Rats, Sprague-Dawley; D017208:Rats, Wistar; D018709:Statistics, Nonparametric
chemical_list: D001672:Biocompatible Materials; C084064:Gengiflex; D008567:Membranes, Artificial; D011138:Polytetrafluoroethylene; D002482:Cellulose