The aims of our study were to compare salivary SIRT-1 concentrations in subjects with periodontitis and those without it in a study with a larger sample size to determine whether there exists an association between salivary SIRT-1 concentrations and the presence of periodontitis and to analyze the potential capability of salivary SIRT-1 concentrations for periodontitis diagnosis. The gene discussed is SIRT1; the disease is periodontitis.