Western Society of Periodontics

Laboratory Studies

Volume Number 3, 1995

The effect of flap management and bioresorbable occlusive devices in GTR treatment of degree III furcation defects. An experimental study in dogs

This study has two objectives: (1) to study if an improved anchorage of the soft tissue flaps during the initial healing period after membrane placement would reduce the tendency for soft tissue recession and allow for healing of large furcation defects; and (2) to use the dog model to determine if the inclusion of a biodegradable device in GTR procedure will prevent soft tissue recession and promote new attachment formation in degree III furcation. Five beagle dogs were used in study 1 and eight dogs in study 2. In each animal, the third premolar of the left or right side of the mandible was selected as test site, using the contralateral tooth as control. Two months prior to the start of the experiment the second and fourth premolars in each side of the mandible were extracted. A large edentulous space was thus created. In study 1, degree III furcation defects were created and treated by e-PTFE membrane in the test and no membrane in the control site. In study 2, a bioresorbable membrane (Resolute) was installed in the test, and an e-PTFE membrane in the control sites. The e-PTFE membranes were removed after 30 days. The animals were sacrificed after five months. Biopsies then were obtained and analyzed histologically for new connective tissue attachment and bone. The results of this study demonstrated that large furcation defects can be regenerated by GTR therapy provided that the soft tissue flaps covering the membrane are prevented from receding apical of the furcation fornix during healing and the clot in the furcation defect remains noninfected. The study also showed that a biodegradable membrane is equally effective as a nondegradable Teflon membrane in GTR procedure. [S.L.]