New biomarker evidence of oxidative DNA damage in whole saliva from clinically healthy and periodontally diseased individuals

BACKGROUND: There is an increasing body of evidence implicating reactive oxygen species in the pathogenesis of periodontal tissue destruction. 8-Hydroxy-deoxyguanosine (8-OHdG) is one of the most commonly used markers to evaluate oxidative damage in a number of disorders including chronic inflammatory diseases. The aim of the present study was to evaluate 8-OHdG levels in whole saliva of patients with periodontitis and to assess the changes after initial treatment. METHODS: Saliva samples were collected from 78 patients with untreated periodontitis and 17 healthy control subjects. Clinical parameters and levels of 8-OHdG were assessed first to establish a baseline and again after initial periodontal treatment from 15 patients. 8-OHdG levels were determined by enzyme-linked immunosorbent assay. RESULTS: The mean value of 8-OHdG in the saliva of periodontally diseased subjects, 4.28 +/- 0.10 ng/ml, was significantly higher (P<0.01) than that of clinically healthy subjects (1.56 +/- 0.10 ng/ml). A significant decrease in salivary 8-OHdG was observed after therapy (P<0.01). CONCLUSION: In the present study, we evaluated for the first time 8-OHdG levels in whole saliva of patients with periodontitis and assessed changes after initial periodontal treatment. Our study indicated that 8-OHdG levels in saliva appear to reflect the status of periodontal health.