CXCL8 and periodontal disorder: For interleukin 8 in stage two disease, we have M = 49.21, Sd = 7.33, t = −7.11, df = 41, compared to stage four where M = 70.21, Sd = 11.73, t = −6.75, df = 28.69, and for TNF α in stage two periodontal disease we observed that M = 30.63, Sd = 6.23, t = −11.94, df = 41, while in stage four M = 57.47, Sd = 8.51, t = −11.51, df = 32.00 (p < 0.05) (Table 19).