Efficacious guided tissue regeneration for intrabony, furcation class II, and recession defects can be accomplished with both nonresorbable and bioresorbable barriers. The potential for regeneration of the periodontium is highly dependent on defect morphology and the availability of "progenitor cells." Many factors associated with surgical technique and barrier properties influence the regenerative outcome of guided tissue regeneration. Maintained flap coverage of the barrier minimizes epithelial down-growth as well as the risk of bacterial contamination of the barrier and the healing wound. Coverage of the newly regenerated tissues after removal of nonresorbable barriers is essential. The use of bioresorbable barriers eliminates a second operation for membrane removal and the associated potential trauma to the regenerating tissues. A stringent postoperative plaque control regimen is necessary during the healing period. The use of systemic antibiotics, prescribed concomitantly with insertion of the barriers has limited effect in controlling various pathogens and is therefore questionable.