Activity of enzymatic antioxidants in periodontitis: A systematic overview of the literature.

Periodontitis is initiated by a bacterial infection and an abnormal immune response of the host resulting in the formation of dysbiotic subgingival biofilm and the progressive destruction of the attachment apparatus of the teeth. It is believed that disturbances in the local and/or general indicators of oxidative stress are one of the mechanisms in the etiopathogenesis of periodontitis. Organisms using oxygen in their metabolic processes are equipped with mechanisms that protect against the activity of oxygen-free radicals. They are commonly referred to as 'the antioxidative barrier of the system'. The main enzymatic antioxidants which have been widely studied in the gingival fluid, saliva and blood serum of patients with periodontitis are superoxide dismutase (SOD), glutathione peroxidase (GPx) and catalase (CAT). The aim of this systematic overview of the literature was to present the current research on the activity of these antioxidant enzymes in the gingival fluid, saliva and blood serum of patients with periodontitis. Findings on the activity of these enzymes in the gingival tissue, gingival fluid, saliva, and blood serum in the course of the types of periodontitis that have been classified so far (chronic or aggressive) are quite disparate. Their activity in the gingival tissue was usually elevated, whereas in the saliva it was reduced. These differences may have resulted from the different methods of biochemically assessing their activity, and may have not reflected the stage and/or the risk of progression of periodontitis.