implants - international magazine of oral implantology

I research Figs. 1 & 2_Exposure of the recipient site for the graft prior to harvest, measurement of its dimensions and the minimal time elapsed between graft harvest and placement. Fig. 3_Preoperative situation. Fig. 4_Mean surgical time of five minutes for harvesting. Fig. 5_Inferior osteotomy connecting the posterior and anterior vertical cuts. Figs. 6 & 7_Fixing of the block grafts after appropriate separation into smaller parts. _Introduction Thedentalrehabilitationofpartiallyortotallyeden- tulouspatientswithoralimplantshasbecomecommon practice with reliable long-term results.1 However, un- favourablelocalconditionsofthealveolarridgedueto atrophy,periodontaldisease,traumasequel,malforma- tion or neoplasia may cause insufficient bone volume, which may complicate the therapy of the masticatory function with dental implants.2 When alveolar ridges lack the appropriate bone volume, additional surgical reconstructiveproceduresarerequired. The use of autologous bone grafts with dental im- plants was described originally by Brånemark et al. in 1975,andtodayisawell-acceptedprocedureinoraland maxillofacial rehabilitation.3-5 Insertion of an en- dosseous implant requires sufficient bone volume for completebonecoverage.Physiologically,anidealbone grafting material should provide osteogenicity, os- teoinductivityandosteoconductivityfornewbonefor- mation. Despite some recent advances in bone-substi- tute technology, autogenous bone grafts remain the “gold standard” in reconstructive surgeries because of their osteoinductive, osteoconductive and non-im- munogenicproperties.Guidedboneregeneration(GBR) is an alternative technique to onlay grafting for lo- calisedalveolarridgeaugmentationpriortodentalim- plant placement.6, 7 The clinical potential of membrane techniques for bone regeneration was recognised by Nyman et al.8 They demonstrated that membranes act as a physical barrier when applied over bone defects, preventingtheingrowthofcompeting,non-osteogenic cellsintothemembrane-protectedspace.7,9 Spacepro- vision, such as guided tissue regeneration, was shown to be effective in regenerating new bone on atrophied alveolar ridge, either vertically or horizontally, with the use of a membrane. Similar to onlay bone graft, which also serves as a space maintainer, GBR may incur simi- larcomplicationsthatpertaintotheuseofonlaygraft. Complications related to GBR may come from mem- brane exposure, miniscrew exposure and contamina- tion.Exposedmembranesorfixationscrewsoftencause local inflammation with decreased bone formation.10 Retromolar bone grafts prior to implant placement Outcomes and complications—Part I Authors_Andreas Sakkas, Carsten Winter, Frank Wilde & Alexander Schramm, Germany 06 I implants3_2013 Fig. 5 Fig. 6 Fig. 2 Fig. 3 Fig. 4 Fig. 1