Is adrenomedullin upregulation due to apical periodontitis independent of periodontal disease?

To investigate the relationship between apical periodontitis [AP] severity and inflammatory markers [interleukin (IL)-12, tumor necrosis factor-alpha (TNF-alpha), and Mid-Regional Pro Adrenomedullin (MR-proADM)] in patients with AP. A total of 162 subjects were divided into three categories: AP group (n = 80), periodontitis (P) group (n = 42), healthy control group (n = 40). The scoring of disease severity in 80 AP patients without any periodontal disease, using dental radiographs, was based on "The Abscess Score" (AS), as those having at least 1 tooth with AP and severity of PAI 3-4 were classified as AS 1 (mild); those with only1 tooth and severity of PAI 5 as AS 2 (moderate) and those having > 2 tooth with severity of PAI 5 as AS 3 (severe). Blood samples were collected from all of the patients. Enzyme-linked immunosorbent assay was used to evaluate the samples. The MR-pro ADM levels of both the AP and P groups were considerably higher than the control group (p < 0.01). The IL-12 levels of the AP group were higher than the P and control groups (p < 0.05). TNF-alpha levels of the P group were significantly higher than both the AP and control groups (p < 0.01). MR-pro ADM levels of both the AP and Periodontitis groups were higher than the control group. TNF-alpha was a biomarker of periodontitis, while IL-12 was a biomarker of apical periodontitis.