[Periodontal disease and crevicular neutrophils. Role of superoxide radicals].

One early biochemical process in PMN activation is the stimulation of the NADPH oxidase membrane enzyme, which produces a flux of superoxide radicals, directed towards the extracellular place. These radicals initiate bacterial destruction; however they can react against the periodontal tissue and lead to its destruction, either when too many of them are produced, or when they are not adequately neutralized by the antioxidant activity of the gingival fluid. Striking a proper balance between the activation state of crevicular PMN and the antioxidant activity of the gingival fluid may be a critical factor in determining whether PMN response to plaque bacteria is either protective or destructive for the parodontium.