Saliva concentrations of RANKL and osteoprotegerin in smoker versus non-smoker chronic periodontitis patients

PubMed ID: 18727653Objectives: To compare the salivary receptor activator of NF-?B ligand (RANKL) and osteoprotegerin (OPG) concentrations in smokers versus non-smokers with chronic periodontitis. Material and Methods: Whole saliva samples were obtained from 67 untreated chronic periodontitis patients, of whom 34 were smokers, and from 44 maintenance patients, of whom 22 were smokers. Full-mouth clinical periodontal measurements were recorded. Saliva cotinine, sRANKL and OPG concentrations were determined by ELISA. Statistical analysis was performed using the Mann-Whitney U test, Bonferroni's correction for multiple comparisons and Spearman's correlations. Results: Untreated smokers exhibited significantly higher values of clinical periodontal recordings than untreated non-smokers (all p<0.05). Salivary cotinine level correlated with clinical attachment level (p=0.023). Smoker versus non-smoker maintenance groups showed no significant differences in clinical parameters. There were significant differences in sRANKL and OPG concentrations between untreated and maintenance groups (all p<0.01). Salivary OPG concentration was significantly lower (all p<0.01) and the sRANKLOPG ratio was higher (all p<0.01) in smokers than in non-smokers. OPG concentration correlated positively with probing depth, clinical attachment level and bleeding on probing (all p<0.005) and negatively with pack-year, and cotinine level (p