Saliva can also be used to detect Porphyromonas gingivalis, a bacterium closely associated with periodontitis. In addition, salivary adrenomedullin (AM) and nitric oxide (NO) levels have shown potential for distinguishing patients with aggressive periodontitis from other groups and for indicating the presence of periodontitis, respectively. Other salivary biomarkers such as macrophage inflammatory protein-1α, matrix metalloproteinase-8, interleukin (IL)-1β, IL-6, prostaglandin E2, and tumor necrosis factor (TNF)-α have shown potential for indicating gingivitis and periodontitis. Moreover, salivary levels of Toll-like receptor-4, IL-18, uric acid, aspartate transaminase, and procalcitonin have been found to be higher in patients with periodontitis than in healthy individuals and can be useful in the diagnosis and prognosis of periodontal diseases.