Mechanical stimulation of gingiva reduces plasma 8-OHdG level in rat periodontitis

Objective: Gingival cells respond to periodontal pathogens by generating reactive oxygen species, and such a condition would increase circulating oxidative stress. Improvement of gingival inflammation by toothbrushing may offer clinical benefits on not only periodontal health but also the circulatory conditions. We examined the effects of mechanical stimulation on the plasma 8-hydroxydeoxyguanosine level in a rat periodontitis model. Design: In this experiment, male Wistar rats (n = 18) were divided into three groups. The control group received topical application of pyrogen-free water to the gingival sulcus for 8 weeks, while the other two groups received topical application of bacterial pathogens (lipopolysaccharide and proteases). After 4 weeks, half of the rats in the experimental groups received daily mechanical stimulation with an electric toothbrush for 4 weeks. Results: Rats treated with bacterial pathogens presented periodontal tissue damage and increased plasma levels of 8-hydroxydeoxyguanosine. Mechanical stimulation by toothbrushing decreased gingival inflammation and oxidative DNA damage indicated by a decrease in plasma 8-hydroxydeoxyguanosine. Conclusions: Mechanical stimulation of periodontally involved gingiva reduced 8-hydroxydeoxyguanosine in plasma and may contribute to a reduction in circulating oxidative stress associated molecules. (C) 2007 Elsevier Ltd. All rights reserved.