Interleukin-17, RANKL, and Osteoprotegerin Levels in Gingival Crevicular Fluid From Smoking and Non-Smoking Patients With Chronic Periodontitis During Initial Periodontal Treatment

Background: This study was performed to evaluate the effects of initial periodontal treatment on the gingival crevicular fluid (GCF) levels of interleukin (IL)-17, soluble receptor activator of nuclear factor-kappa B ligand (sRANKL), and osteoprotegerin (OPG) in smoking and non-smoking patients with chronic periodontitis. Methods: At baseline, GCF samples were obtained from 10 smoking and 10 non-smoking systemically healthy patients with chronic periodontitis. Initial periodontal treatment, consisting of motivation and instruction for daily plaque control and scaling and root planing (SRP), was performed. GCF sampling and clinical periodontal measurements were repeated 4 weeks after completion of SRP. The data were tested statistically by the Student t and Wilcoxon matched-pairs test and Spearman correlation analysis. Results: All clinical periodontal measurements had decreased significantly 4 weeks after SRP (P<0.001). GCF volume and the total amount and concentration of OPG decreased in smokers and non-smokers after SRP, whereas the IL-17 concentration increased (P <0.05). sRANKL levels did not differ between groups or with SRP (P >0.05). Significant correlations were found between baseline IL-17 and receptor activator of nuclear factor-kappa B ligand (RANKL) levels and between baseline papilla bleeding index and OPG levels (P <0.001 and P <0.05, respectively). Conclusions: Neither smoking nor periodontal inflammation seemed to influence GCF RANKL levels in systemically healthy patients with chronic periodontitis. Smoking and non-smoking patients with chronic periodontitis were not affected differently by the initial periodontal treatment with regard to GCF IL-17 and OPG concentrations. J Periodontol 2009;80:1274-1280.