[The effect of superoxide dismutase on the inflammation induced by periodontal pathogenic bacteria and wound healing of gingival incision].

The therapeutic effect of superoxide dismutase (SOD) and the role of O2- were assessed on 3 groups of Wistar rats (total 115). Fifty-four received injections of gingival bacteria or of anaerobically cultured rat dental plaque in their peritoneum, then received both intravenous (i.v.) and intraperitoneal (i.p.) injection of SOD. The rats were killed 48 hours later to collect their peritoneal exudate for cell count and for acid phosphatase activity assessment. Twenty-six received injections of bacteria in their footpads, after which SOD was administered intravenously. These rats were killed at 6 hours, 48 hours and 1 week respectively for histological examination. The gingiva of 26 rats were incised to create artificial lesions. The rats were killed at 24 or 48 hours and examined histologically. The nine remaining rats were used as controls (untreated) for the 3 experiments. The results of the 3 experiments showed that: Injection of SOD reduced exudation and acid phosphatase activity enhanced by the injection of B. gingivalis, at dosages of 1, 5 mg/kg i.p. and 5 mg/kg i.v., but 10 mg/kg i.p. had no apparent effect; i.v. injection of SOD had inhibitory effects on cell infiltration of B. gingivalis into the footpad, and the increase in fibrin and fibroblast formation through time was greater in SOD-administered rats; a decreased cell infiltration rate and increased fibrin network, fibroblast proliferation and gingival tissue regeneration occurred in specimens with artificial lesions given SOD. Apparently SOD has a curative effect on both inflammatory reaction induced by B. gingivalis and periodontal wound healing.