Protein carbonyl levels in serum and gingival crevicular fluid in patients with chronic periodontitis

OBJECTIVE: Evidence reveals the role of reactive oxygen species (ROS) in many pathologies including periodontitis. Protein carbonylation is the most widely used biomarker for oxidative damage to proteins, and reflects cellular damage induced by ROS. In this study protein carbonyl (PC) levels in serum and gingival crevicular fluid (GCF) in patients with chronic periodontitis (CP) was evaluated. MATERIALS AND METHODS: Thirty-three patients with CP and 24 healthy controls were included in the study. Following the clinical measurements and samplings, total protein levels in serum and GCF were determined by Bradford method, and serum and GCF PC levels were measured by modified Levine method. RESULTS: PC levels in serum and GCF were significantly higher in the CP group compared to the control group (p<0.05). In all subjects, serum and GCF PC levels showed statistically significant positive correlations with all clinical parameters (p<0.05). CONCLUSIONS: The results suggest that both systemic and local/periodontal protein carbonylation increase in CP compared to health and that elevated levels of PCs may be a sign of oxidative damage in periodontitis and correlate well with the periodontal status.