Free soluble receptor activator of nuclear factor‐κb ligand in gingival crevicular fluid correlates with distinct pathogens in periodontitis patients

AIM: The aim of the experiment was to investigate the levels of free soluble receptor activator of nuclear factor-kb ligand (sRANKL) in periodontal health and disease and their correlations to clinical parameters and important periodontal pathogens. MATERIAL AND METHODS: Chronic periodontitis (n=35) and periodontally healthy (n=38) subjects participated in the present study. Pocket depth, recession and bleeding index were recorded at a total of 221 sites. Subgingival plaque samples from these sites were analysed for the levels of Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Tannerella forsythia and Treponema denticola. Gingival crevicular fluid samples were analysed with ELISA for levels of free sRANKL. Comparisons between groups were performed by applying non-parametric tests (Mann-Whitney) and correlations among parameters were sought for with Spearman's r coefficient. RESULTS: Mean levels of free sRANKL were higher in periodontitis subjects and correlated significantly with mean counts of T. denticola on the subject level and P. gingivalis, T. denticola on the site level (Spearman's r coefficient, p<0.05), but not with clinical parameters. No correlations were found between the levels of free sRANKL and investigated parameters in periodontally healthy individuals. No effect of smoking was found on investigated parameters and correlations (univariate analysis of variance and pairwise comparisons). CONCLUSIONS: Findings from the present study suggest a correlation of levels of sRANKL with important pathogens in periodontitis patients.