Oxidative Stress & Oral Health

Oxidative stress is a disturbance in the systemic balance of oxidants and antioxidants. It is the result of overproduction of free radicals, including reactive oxygen species, or ROS. Lifestyle factors such as poor diet, and alcohol consumption contribute to oxidative stress, as do environmental factors such as chemical pollutants and even second-hand smoke. Oxidative stress may be systemic, affecting the whole body, as well as localized, as in oral soft tissues. Recent studies have shown that inflammation and oxidative stress are causative factors common to many chronic diseases, including periodontitis, atherosclerosis, diabetes, and rheumatoid arthritis. Also, gingivitis and periodontitis are contributing factors to oxidative stress and, therefore, to inflammatory disease.

What is oxidative stress?

In normal, healthy individuals, the metabolic process results in balanced levels of free-radical reactive oxygen species (ROS) and antioxidants. If the normal oxidant/antioxidant balance is disturbed, it can result in a pro-oxidant burden, that is, a proliferation of ROS and free radicals. The overabundance of oxidants is called oxidative stress.

What are the effects of oxidative stress?

Oxidative stress can lead to cell damage through micro-damage to the cell membrane, protein deactivation, DNA damage, and stimulation of cell signaling molecule-induced tissue damage. Some molecules are more vulnerable to oxidation (i.e., "electron theft") than others. In particular, some of the molecules in cell walls, containing unsaturated lipids, are particularly susceptible to the attack of free radicals. Other vulnerable molecules include RNA, DNA, and protein enzymes.

Why is oxidative stress a particular problem in oral tissues?

Oral cells are uniquely susceptible to free radical damage because the mucus membranes allow rapid absorption of substances across their surfaces. In oral tissues, infection from gum disease can generate oxidative stress as can alcohol, nicotine, hydrogen peroxide, and other dental procedures and substances such as hydrogen peroxide, dental cements, composite fillings. The increase in free radicals from oxidative stress leads to further breakdown of cell walls and oral tissue.

Oxidative stress: the oral and systemic link

Not only does oxidative stress exacerbate inflammation in the oral tissues, recent scientific studies have shown it is a contributing factor to systemic inflammatory diseases, including rheumatoid arthritis and cardiovascular disease. Because of the association between gum disease, inflammation and oxidative stress, it is critical to control gum disease and to maintain the balance between oxidants and antioxidants in oral tissues.