The chapters of Studies on Periodontal Disease comprise four parts. Part 1 provides basic sciences from the general to the particular. The findings of cell culture and animal models supply the mechanism between periodontal disease and oxidative stress. In part 2, human clinical studies are mainly addressed. The effects of periodontal therapy on circulating oxidative stress are also discussed. The relationships between periodontal disease and systemic diseases are examined in part 3. The involvement of oxidative stress and inflammation are discussed through in vivo and in vitro study results. Part 4 discusses future strategies, including the effects of antioxidants and nutrition on periodontal disease. This thorough examination of the relationship between oxidative stress and periodontal disease is essential reading for researchers in oxidative stress and periodontal clinicians, alike.