The aim of this study is to evaluate the effect of periodontal treatment on systemic inflammation and quality of life of individuals with metabolic syndrome. There will be a randomized clinical trial with patients from the clinic of Endocrinology - Prediabetes (Hospital de Clinicas de Porto Alegre) and outpatient dental clinic of the Faculty of Dentistry, Federal University of Rio Grande do Sul (UFRGS), who have a diagnosis of metabolic syndrome and diagnosis of periodontitis. The clinical trial will consist of an arm where it will be immediately periodontal treatment (test group) and another arm which will be held later periodontal treatment (control group). The study will last six months , and after this period, the control group will receive the same treatment to the test group . A socio-demographic questionnaire will be applied by a trained interviewer , so that data on income, education , behavioral habits , medical and dental history . Complete periodontal examination will be conducted at 6 sites per tooth for all teeth present at baseline and 3 and 6 months after periodontal treatment . In addition to the tests required for the diagnosis of metabolic syndrome , will be asked the same blood tests at 3 and 6 months after periodontal treatment (total cholesterol , LDL and HDL , fasting glucose , triglycerides , C-reactive protein). Aliquots of plasma from blood collected in each experimental point are stored at -80 ° C for analysis of interleukin- 6, Tumor Necrosis Factor- α (TNF-α) , Glucagon Like Peptide-1 (GLP-1) and adiponectin. At each clinical examination will be collected gingival crevicular fluid , supra and subgingival biofilm . Versions of the questionnaires validated in Brazil (OHIP-14)and WHOQoL Bref will be applied to assess quality of life at baseline and after 6 months of the study . The primary outcome will be change in glycated hemoglobin and secondary outcomes will be changes in serum fibrinogen and C-reactive protein.The hypothesis of this study considers that periodontal treatment can alter the serum levels of C-reactive protein, fibrinogen and glycosylated hemoglobin in patients with metabolic syndrome and thereby contribute to improved quality of life. The objective of this study is to evaluate the effect of periodontal treatment on systemic inflammation and quality of life of individuals with metabolic syndrome.