**Abstract**

Excessive reactive oxygen species production plays an important role in the pathogenesis of various chronic inflammatory diseases, including periodontal disease. Reactive oxygen species could damage the cells and the tissues. In the pathogenesis of periodontal diseases, the increased PMN count and activity cause a high rate of ROS release. This leads to increased oxidative stress in periodontal tissues. Periodontal tissues require adequate levels of antioxidants to prevent tissue damage caused by reactive oxygen species. The use of antioxidants in the treatment of periodontal disease and periodontal health has gained importance in recent studies. Antioxidants can be used to treat periodontal disease locally or systemically. Therefore, this chapter focuses on the effects of antioxidant on periodontal tissues.

**Keywords:** antioxidants, oxidative stress, periodontal diseases, reactive oxygen species, tissue damage
