Salivary cytokine levels in subjects with chronic periodontitis and in periodontally healthy individuals: a cross‐sectional study

Background and Objective: Saliva has been proposed as a noninvasive diagnostic fluid that could be used in the diagnosis of oral and systemic diseases. The levels of salivary biomarkers, such as cytokines, could potentially be used as a surrogate to distinguish periodontally healthy individuals from subjects with periodontitis. Therefore, the goal of the present investigation was to determine if the levels of 10 different cytokines in saliva differed between a group of periodontally healthy individuals and a group of subjects with periodontitis. Correlations between the concentrations of these 10 cytokines and clinical parameters of periodontal disease were also examined. Material and Methods: In this cross‐sectional study, 74 subjects with chronic periodontitis and 44 periodontally healthy individuals were periodontally examined and had the levels of granulocyte–macrophage colony‐stimulating factor, interleukin‐1β, interleukin‐2, interleukin‐4, interleukin‐5, interleukin‐6, interleukin‐8, interleukin‐10, interferon‐γ and tumor necrosis factor‐α measured in whole saliva using a multiplexed bead immunoassay (Luminex). Significance of statistical differences in the levels of salivary cytokines between groups was determined using nonparametric analysis of covariance, adjusting for age and smoking status. The Spearman rank correlation coefficient was used to explore associations between the mean levels of salivary cytokines and mean clinical parameters. Results: There were no statistically significant differences between groups for any of the cytokines. There were weak, statistically significant positive associations between salivary interleukin‐8 and pocket depth ( r s = 0.2, p < 0.05) and bleeding on probing ( r s = 0.2, p < 0.05), and weak negative correlations between salivary interleukin‐10 and attachment level ( r s = −0.2, p < 0.05) and bleeding on probing ( r s = −0.3, p < 0.001). Conclusion: Mean salivary levels of granulocyte–macrophage colony‐stimulating factor, interleukin‐1β, interleukin‐2, interleukin‐4, interleukin‐5, interleukin‐6, interleukin‐8, interleukin‐10, interferon‐γ and tumor necrosis factor‐α could not discriminate between periodontal health and disease.