TNF and IL-1β levels are the two main indicators by which inflammation can be determined in apical periodontitis.26The levels of IL-1β in the unstimulated saliva are also higher in patients with periodontitis compared with the healthy control and gingivitis group.27This indicates that this IL-1β is an important element of the inflammatory process in apical periodontitis. Here, TNF is linked to periapical periodontitis.