Figure 2.

Schematic overview of the key biomarkers related to periodontal disease progression. Initial events are triggered by LPS from Gram-negative plaque biofilms on the periodontal tissues. As a first line of defense, PMNs are recruited to the site. Monocytes and activated macrophages respond to endotoxin by releasing cytokines (TNF and IL-1) that direct further destruction processes. MMPs, which can act as powerful collagen-destroying enzymes, are produced by fibroblasts and PMNs. TNF, IL-1, and receptor activator of nuclear factor-kappa B ligand (RANKL) are elevated in active sites and mediate osteoclastogenesis and bone breakdown. Bone-specific markers, such as ICTP, are released into the surrounding area and transported by way of gingival crevicular fluid into the sulcus or pocket and serve as potential biomarkers for periodontal disease detection. Adapted with permission from Blackwell Publishing.¹