IMPLANT PLACEMENT IN LARGE EDENTULOUS RIDGES EXPANDED BY GBR USING A BIORESORBABLE COLLAGEN MEMBRANE

The purpose of this study is to evaluate the possibility of expanding an edentulous ridge spanning two or more teeth by a two-step technique with bioresorbable collagen membranes. Sixteen healthy patients were treated four in the mandible and 12 in the maxilla. The borderline of the crest width was less than or equal to 4 mm. In each patient only o ne ridge augmentation was performed. After elevation of a full-thickne ss flap a surgical stent was positioned to identify the area of ideal implant positioning. The width of the crest at the location of the sur gical stent was measured at the time of GBR procedure and 7 to 12 mont hs later during implant insertion. Native collagen sponges were placed buccally and lingually and a collagen membrane was shaped and trimmed to completely cover the edentulous ridge. The flaps were sutured to a chieve primary closure. Antibiotic and clorhexidine mouthrinse were pr escribed, and the patients were recalled every 2 weeks. At implant pla cement the mean increase in the size of the crest was 2.49 mm (+/- 1,6 1 mm). In 12 out of 16 patients (75%) if was possible to insert 27 imp lants according to the prosthetic need established previously: All imp lants were successfully loaded, and in the four cases where no appreci able results were obtained no clinical complications or loss of hard a nd soft tissue were observed.