Fig. 2
Salivary cytokine levels and detection frequencies in healthy and diseased groups. Presented are concentrations of (a) CXCL8 (IL-8) and (b) IL-1β in each group. The box-and-whisker plots indicate the median value (horizontal line), the interquartile range (IQR as bottom and top of the box) and the whiskers extending to the extreme values within 1.5xIQR. Points beyond the whiskers are outliers as defined by the Tukey method. Dashed horizontal lines indicate the assay’s lower limit of detection (LOD) and upper limit of quantification (ULOQ). Values below the LOD were imputed as LOD/2. Significance was determined using Kruskal–Wallis test followed by Dunn’s correction for multiple comparisons (* p < 0.05). (c) The bar chart depicts the percentage of samples with detectable IL-17A, IL-6 and TGF-β1 in each group. Group differences assessed by Chi-square test for trend are presented (*p < 0.05, **p < 0.01). Data in all panels (a–c) are from the same cohorts: healthy (n = 20), gingivitis (n = 19) and periodontitis (n = 20).
