RESPONSE OF REGENERATIVE TISSUES TO PLAQUE - A HISTOLOGICAL STUDY IN MONKEYS

THIS STUDY WAS DESIGNED TO DETERMINE the histologic response of regene rated tissue to plaque, using an adult Taiwan monkey model with chroni cally-inflamed surgically-created, periodontal defects. Standardized 2 -walled periodontal defects were surgically created at the mesial of t he mandibular lateral incisor on one side. Sutures, 3-0 braided silk, were placed for 8 weeks and tissues positioned so that denuded root su rfaces were exposed to plaque, with the subsequent development of the chronically-inflamed periodental tissues. At 8 weeks the defects were subjected to guided tissue regeneration procedures using expanded poly tetrafluoroethylene membrane and allowed to heal for 6 months. Contral ateral clinically healthy sites, without surgical procedures, were use d as controls. In bath experimental (membrane) and control sites, silk ligatures were placed to allow plaque accumulation for 2 or 10 weeks. Four monkeys were sacrificed at each time point and specimens process ed for histologic and histometric study. The results indicated that pl aque-induced inflammation was less at sites treated by guided tissue r egenerative procedures when compared to originally clinically-healthy sites exposed to plaque for the same duration. However, histologically the newly formed osseous tissue was compromised under these condition s.