Effect of non-surgical periodontal therapy on superoxide dismutase levels in gingival tissues of chronic periodontitis patients: A clinical and spectophotometric analysis

BACKGROUND: Superoxide dismutase (SOD), an antioxidant acting against superoxide (oxygen radical, O-2(center dot-)), it is released in inflammatory pathways and causes connective tissue breakdown. Increased SOD activity in inflamed gingiva may indicate increased O-2(center dot-) radical generation by neutrophils and other inflammatory cells at the diseased site. The aim of the study was to evaluate the effects of non-surgical periodontal therapy (NSPT) on SOD levels in gingival tissues of chronic periodontitis patients. METHODS: Forty subjects: 20 periodontally healthy (Control) and 20 chronic periodontitis (Test); age range 24-55 years were recruited. Gingival tissue samples were collected by excising the inner lining of the periodontal pocket at baseline (prior to non-surgical periodontal therapy) and 2 months post therapy. In controls, tissue samples were obtained immediately after tooth extraction scheduled for orthodontic reasons. Clinical parameters included probing depth, clinical attachment level, gingival index, bleeding index, plaque index. SOD activities were assessed spectrophotometrically at baseline and 2 months post NSPT, results were analysed statistically. RESULTS: At baseline, patients with chronic periodontitis had higher mean SOD activity (2.73 +/- 1.36) than the control subjects (1.12 +/- 1.13) with p = 0.00003 (p < 0.05). At 2 months post NSPT median SOD level (1.00) had come close to median SOD value of control group (0.85); p = 0.99 (p > 0.05). The resolution of inflammation with successful NSPT resulted in decreased SOD levels as in control group. Clinical parameters in patients with chronic periodontitis showed a significant improvement 2 months post NSPT (p < 0.05). CONCLUSION: Non-surgical periodontal therapy significantly improves the clinical parameters and restores previously increased SOD levels to normal in chronic periodontitis patients.