Methods: A total of 67 patients diagnosed with periodontitis were classified according to the 2017 World Workshop Classification into Stage I/II vs. Stage III/IV and Grade B vs. Grade C. Unstimulated saliva samples were collected and analyzed for cortisol using electrochemiluminescence immunoassay, and for IL-1β and IL-6 using ELISA. The gene discussed is IL1B; the disease is periodontitis.