8‐Hydroxy‐Deoxyguanosine Levels in Gingival Crevicular Fluid and Saliva in Patients With Chronic Periodontitis After Initial Periodontal Treatment

Background: This study evaluates the effects of initial periodontal treatment on the gingival crevicular fluid (GCF) and salivary levels of 8‐hydroxy‐deoxyguanosine (8‐OHdG) as a marker of oxidative deoxyribonucleic acid (DNA) damage in patients with chronic periodontitis (CP). Methods: At baseline, clinical parameters were determined and GCF and saliva samples were obtained from 24 patients with CP and 24 individuals with clinically healthy periodontium. GCF, saliva samples, and clinical periodontal measurements were repeated at day 10, 1 month, and 3 months following initial periodontal therapy in patients with CP. 8‐OHdG levels of GCF and saliva samples were investigated by using an enzyme‐linked immunosorbent assay. Results: Statistically significant higher 8‐OHdG levels of GCF and a significant decrease after initial periodontal therapy were determined in the CP group ( P <0.001). A significant positive correlation was found between 8‐OHdG levels of GCF and clinical periodontal measurements ( P <0.001). However, salivary levels of 8‐OHdG did not differ between groups or during initial periodontal therapy ( P >0.05). Conclusions: This study reveals that DNA injury and oxidative stress increase in tissue cells and especially in periodontal pockets in patients with CP, and the periodontal treatment results in a significant decrease of 8‐OHdG levels in the GCF samples. To the best of our knowledge, this study evaluates for the first time, 8‐OHdG levels in GCF, which is shown to be more useful as a biomarker than saliva. 8‐OHdG was found to be important and may reveal the severity of periodontal disease and the effect of periodontal therapy.