Biological roles of gingival epithelial cells in periodontitis patient

Gingival epithelium is a stratified squamous epithelium that functions as the barrier between the outside environment and the host. In the oral cavity, epithelial tissues are constantly exposed to a variety of bacteria, but most individuals maintain healthy homeostasis. Epithelial cells contribute to the innate host response, and antimicrobial peptide expression in all human epithelia, including oral epithelia. Gingival epithelium consists of oral epithelium and gingival sulcus epithelium, and junctional epithelium. Periodontitis is a chronic disease characterized by a deepening periodontal pocket, destruction of connective tissue and alveolar bone. The number of PMN and T cells increases face to epithelium with the progression of disease. Gingival epithelial cells produce inflammatory cytokines, such as interleukin (IL)-1, IL-8 and others and play a role to cause the initiation and progression of inflammation. Furthermore, gingival epithelium appears to play a role in the adaptive immune response by stimulating antigen-specific CD 4(+) T cells. Gingival epithelial down growth into periodontal defects is obstacle for periodontal regeneration therapy. Clinical application of enamel matrix protein or guided tissue regeneration method with barrier membrane has been known to inhibit the gingival epithelial down growth and induce periodontal regeneration in intrabony defects with periodontis. Thus, the knowledge of the biological roles of gingival epithelial cells may open the way for development of new therapeutic agents for periodontal diseases or peri-implantitis