Oxidative stress in diabetes and periodontitis.

Oxidative stress is an imbalance between the production of a reactive oxygen species and the antioxidant defense, leading to tissue damage. The produced reactive oxygen species, such as superoxide anion, hydroxyl radical, and peroxyl radical result in damage to many biological molecules (including DNA, lipids, and protein), and the prolonged existence of these reactive oxygen species promotes severe tissue damage and cell death.[1,2] It has been proposed that there is a causal relationship between insulin resistance, oxidative stress, and periodontitis and that hyperglycemia is a major factor responsible for the activation of oxidative stress.[1,2]