Effect of different microstructures of e-PTFE membranes on bone regeneration and soft tissue response: a histologic study in canine mandible

The purpose of the present study was to compare the effect of 3 types of ti tanium reinforced e-PTFE membranes (GTRM #1, #2, and #3) on bone regenerati on and tissue integration. GTRM #1 was a standard titanium reinforced membr ane, GTRM #2 was a prototype characterized by a more open total surface mic rostructure and GTRM #3 was a prototype characterized by two extremely poro us external layers separated by a totally occlusive internal layer. The mem branes were used to cover saddle type ridge defects surgically created in t he mandible of 6 dogs. After a healing period of 6 months, all the membrane protected sites demonstrated almost complete osseous healing of the defect s. GTRM #3 specimens showed the most favourable biologic response, in fact they were characterized by a larger surface of contact between the membrane and the regenerated bone, but from a clinical point of view GTRM #3 materi al was too difficult to remove. The results of this study suggest that an e xtremely open porous microstructure, in combination with a totally occlusiv e barrier, may provide significant improvements in regenerative outcomes. H owever, these design characteristics may be applied only to resorbable devi ces, which do not require removal.