Figure 8b. Illustrations of a periodontal pocket and its treatment. (a) On the right, a normal periodontal ligament is depicted (thick arrows). On the left, the portion affected by periodontal disease results in a periodontal pocket (thin arrow), with resorption of adjacent bone (arrowheads). (b) The periodontal pocket is treated by filling it with freeze-dried bone (curved arrow), by placing a expanded polytetrafluoroethylene membrane (straight arrow) between soft tissues, and by performing a bone graft to prevent soft-tissue ingrowth. (Reprinted, with permission, from reference 8.)