ABSTRACT
<p><b>BACKGROUND</b>Guided tissue regeneration procedures provide predictable reconstruction of periodontal tissues in the treatment of furcation involvements in animals and humans. This study was to compare long-term effectiveness of two different types of polylactic acid (PLA) membranes on periodontal regeneration in surgically created class II furcation defects in dogs.</p><p><b>METHODS</b>Full thickness mucoperiosteal flap was raised on the buccal aspects of the experimental teeth and class II furcation defects having 5 mm vertical dimensions were created on mandibular premolar III and IV on each quadrant. The exposed root surfaces were thoroughly planed and PLA membranes were placed over the experimental defects on both sites. One site received liquid polymer membrane (LPM), and resorbable periodontal mesh (RPM) membranes were applied to the other site. The animals were sacrificed at 7 months after surgery and the specimens were processed for histological evaluation.</p><p><b>RESULTS</b>The average length of new attachment formed on the treated roots in both groups ranged from 3.02 mm to 4.5 mm. Complete bone filling was observed at the furcation sites. No statistically significant differences were found between two membranes in any of the parameters (P > 0.05).</p><p><b>CONCLUSION</b>This study demonstrates favorable regenerative outcomes by the use of two different types of PLA membranes that could be used as alternatives for guided tissue regeneration (GTR).</p>