FREEZE-DRIED DURA-MATER FOR GUIDED TISSUE REGENERATION IN POST-EXTRACTION DENTAL IMPLANTS - A CLINICAL AND HISTOLOGIC-STUDY

SOFT MEMBRANES WERE USED in 69 patients for bone regeneration around i mplants (blades and screws, submerged and non-submerged) placed into e xtraction sockets. In about 10% of the patients a prosthetic restorati on was completed immediately, while in the remaining patients the pros theses were connected after a healing period of 3 to 6 months; follow- up ranged from 6 to 30 months. In 22 patients a re-entry procedure was done to evaluate the membrane and in 4 patients a bone biopsy was tak en from 3 to 6 months after the placement of the membrane. In all case s the peri-implant tissues appeared clinically healthy and it was poss ible to see radiographically that the newly formed bone closely adapte d to the implants. In most cases it was possible at 6 months re-entry to see the membrane and detach it from the underlying tissues. There w as a partial dehiscence of the membrane in only 4% of the cases. After 3 months the tissue under the membrane presented macroscopical featur es similar to mature bone, and bone biopsies in all cases showed a spo ngious lamellar bone with a high level of activity and a wide band of osteoid tissue.