Guided tissue regeneration with bioabsorbable and expanded polytetrafluoroethylene barrier membranes in the treatment of naturally occurring periodontal defects in dogs

THE PURPOSE OF THE PRESENT STUDY was to evaluate the healing events and com pare the effects of guided tissue regeneration (GTR) using 3 different memb ranes: a weakly cross-linked bioabsorbable bovine collagen membrane; a stro ngly cross-linked bioabsorbable bovine collagen membrane; and a non-resorba ble ePTFE membrane. Twenty adult female beagle dogs with naturally occurrin g periodontitis were subjected to periodontal probing and scaling. In both right and left mandibular quadrants, mucoperiosteal flaps were raised, and after debridement, the roots of experimental premolar teeth received apical reference notches. The following treatments were randomly assigned: 1) gin gival flap curettage (GFC) + ePTFE membrane, control membrane; 2) GFC + sli ghtly cross-linked collagen membrane, Ist test membrane; and 3) GFC + stron gly cross-linked collagen membrane, 2nd test membrane. The flaps were sutur ed in such a manner that the membranes were completely covered. All dogs re ceived a soft diet for a 2-week period and an oral hygiene program until ti me of sacrifice. The animals were randomly scheduled for sacrifice at 2, 4, 12, and 24 weeks. The ePTFE membranes still in place were removed at 6 wee ks. The jaws were dissected and specimens prepared for descriptive histolog y and histomorphometry. The early resorption of the Ist test membrane was a chieved at 4 weeks, and the 2nd test membrane at 12 weeks, both with normal inflammatory reaction. Measurements of epithelium, connective tissue attac hment, new bone, and neocementum were compared within an animal (paired t t est). Analyses were performed on data at 4, 12, and 24 weeks post-healing; little differences were found between these periods. Limited connective tis sue repair was favored by the placement of all the membranes (about 20%), w ith no statistically significant difference. These findings indicate that b ioabsorbable collagen membranes with different cross-linking and ePTFE barr iers promote similar new attachment in GTR procedures on naturally occurrin g periodontal defects in dogs.