Expression of Reactive Oxygen Species in Junctional and Pocket Epithelium

The generation of reactive oxygen species (ROS) is part of an antimicrobial response to pathogenic challenge and potentially has a deleterious effect on local periodontal tissues. Junctional epithelial cells in periodontal tissue form the initial defensive line against bacterial challenge. In response to this challenge, junctional epithelial cell proliferation and migration occurs and is a key biological response that is associated with the initiation of periodontal attachment loss. The regulation of this process and its contribution to the initiation and progression of disease are not fully understood, but the local expression of antimicrobial peptides, cytokines, and growth factors is involved. However, the expression of ROS-associated molecules by epithelial cells appears to play a significant role in disease onset as well. In this chapter, we summarize the structural organization of junctional and pocket epithelium, the expression of ROS molecules in this cellular compartment, and their possible roles in mediating periodontal disease onset.