Guided tissue regeneration in surgically created 3-walled and 2-walled periodontal osseous defects in monkeys.

BACKGROUND: In the previous clinical studies, guided tissue regeneration resulted in periodontal regeneration after treatment of 3-walled intrabony defects. The purpose of the present study was to compare the regenerative potential of 3-walled and 2-walled surgically created periodontal osseous defects in monkeys following placement of a biocompatible, porous polytetrafluorethylene membrane. METHODS: In each of 8 Taiwan monkeys, 2 maxillary and 2 mandibular teeth were selected for experimentation. Using a diamond bur, 3-walled osseous defects were created on the distal of the maxillary cuspid and the mesial of the mandibular second bicuspid of one side. Two-walled (lingual wall and proximal wall) osseous defects were created on the contralateral side. After root planing, teflon membranes were applied to the mandibular test teeth. In the maxilla, all procedures were the same except for the placement of teflon membranes. Two monkeys were sacrificed 3, 6 and 9 months after operation and prepared for histologic and histometric evaluation. Reentries were performed while the other 2 monkeys were terminated 11 months after operation. RESULTS: Histologic evaluation revealed that new connective tissue attachments were found to a greater extent in the 3-walled periodontal osseous defects treated with teflon membranes compared with the non-membrane sites (p = 0.05). More periodontal regeneration was not predictably obtained in the surgically created 2-walled osseous defects when the teflon membranes were used. CONCLUSIONS: For 3-walled periodontal osseous defects, guided tissue regeneration was superior to conventional periodontal flap surgery. For 2-walled defects, new connective tissue attachment could not be predictably achieved.