Background: Higher levels of receptor activator of nuclear factor kappa-β ligand, i.e., RANKL, were reported among periodontitis patients compared with their healthy peers. This study aimed to measure the salivary level of RANKL among waterpipe smokers and to find the possible correlation between salivary level of RANKL and clinical periodontal parameters.
Materials and methods: This study is a cross-sectional study involving 89 (49 waterpipe smokers and 40 nonsmokers) participants. The whole unstimulated saliva samples were collected for quantitative determination of RNAKL using a human RANKL enzyme-linked immunosorbent assay kit. Plaque index, gingival index, bleeding on probing, periodontal pocket depth (PPD), and clinical attachment level (CAL) were recorded for each participant. Mann-Whitney U-test was used to detect any difference between groups at P < 0.05. Spearman correlation coefficient test was used to test the association between variables. Linear regression was used to investigate the cause-and-effect relationship between the associated variables.
Results: In a comparison, RANKL, PPD, and CAL showed statistical differences (P < 0.05) between waterpipe smokers and nonsmokers. RANKL was found to be positively associated with CAL, and approximately 62.8% of CAL in this study sample could be explained by RANKL. The regression equation was CAL = 1.744 + 0.004 (RANKL).
Conclusions: The salivary level of RANKL was positively related to CAL in this study sample.
Keywords: Clinical attachment level; receptor activator of nuclear factor kappa-β ligand; smokers; waterpipe.