RESUMO
AIM: To compare the levels of the soluble receptor activator of nuclear factor kappa B ligand (sRANKL), osteoprotegerin (OPG) and their relative ratio in gingival crevicular fluid (GCF) among periodontitis patients with varying smoking histories. MATERIAL AND METHODS: GCF samples were collected from 149 periodontitis patients who were never smokers (n=58), former smokers (n=39) and current smokers (n=52). sRANKL and OPG concentrations in GCF were measured by enzyme-linked immunosorbent assays. RESULTS: sRANKL, OPG and their relative ratio were not statistically significant among the never smokers, former smokers and current smokers. However, OPG was significantly reduced and subsequently the sRANKL:OPG ratio was significantly increased in the high pack-years group as compared with never smokers. The positive correlation between pack-years and the sRANKL:OPG ratio remained statistically significant after adjusting for age and current smoking status. CONCLUSION: Increased lifetime exposure to cigarette smoking above a minimum threshold suppresses OPG production and leads to increased sRANKL:OPG. This may partially explain increased bone loss in smoking-related periodontitis.
