By Richard H. Nagelberg, DDS
It is amazing to witness the wide array of therapeutic approaches coming to the world of dentistry. Research enables the development of technologies that are fundamentally changing the landscape of the dental profession. Digital imaging, caries detection lasers, stem cells, digital impressions, and antioxidants are only some of the technologies that are contributing to the enhanced level of care that we can provide for our patients. One of the most promising new technologies available to dental professionals involves the use of antioxidants. Understanding how they work requires revisiting basic chemistry to understand the various events and processes that can cause cellular and tissue damage including oxidative stress, reactive oxygen species, free radicals, oxidation and reduction, and the mechanism of antioxidant action.
Oxidation and reduction reactions involve the transfer of electrons. Bonding forces hold the electrons in their orbit around the nucleus. Loss of an electron results in an open or "dangling" bond, which makes the atom or molecule highly reactive. It is then called a free radical, so free radicals are atoms or molecules that have one or more unpaired electrons. There are many types of free radicals, and those that are of particular concern in biology are derived from oxygen and are called reactive oxygen species (ROS). Oxygen has two unpaired electrons, making oxygen especially susceptible to free radical formation. Reactive oxygen species are necessary intermediates in a variety of enzyme reactions and are required for many life processes. For example, ROS are produced by white blood cells to kill invading pathogens. There are many, many instances of ROS being necessary for maintaining homeostasis. During times of stress, however, ROS levels can increase dramatically. This may also occur with certain drugs, UV exposure or exposure to high heat levels, or exposure to ionizing radiation such as X-rays. Of particular interest to dental professionals is the elevation of free radicals in the presence of infection. The increased levels of ROS can cause cellular damage including damage to the DNA, damage to cell membranes, and protein deactivation. Damage to the DNA may play a role in the development of cancer. The accumulated free radical damage is called oxidative stress.
The free radicals, including reactive oxygen species, can start chain reactions, which are very damaging to cells and tissues. Antioxidants are chemicals that interact with and neutralize free radicals, thus preventing them from causing damage. Antioxidants are also known as "free radical scavengers." Antioxidants terminate these chain reactions by removing free radical intermediates, and inhibiting further oxidation reactions. Antioxidants are produced by the body and are found in various foods and plants. In a homeostatic state, there is a balance of ROS and antioxidants, and free radical tissue damage is not occurring. Tissue damage occurs when free radicals overwhelm the antioxidant reserves in the body.
Most strategies for managing periodontal disease involve control of the causative bacteria. Antioxidants address oral conditions in a totally novel way; namely the manner in which cells and tissues react to bacteria. It is well established that the body mobilizes an inflammatory response to the periodontal pathogens. Oral tissue, however, also reacts to other insults such as tobacco, alcohol, dental materials, and others by mounting an inflammatory response. Research indicates a relationship between high levels of inflammation and oxidative stress markers and low levels of naturally occurring salivary antioxidants. This correlation has been noted in patients with periodontitis, oral lichen planus, peri-implantitis, aphthous ulcers, xerostomia, smokers, and diabetics among others. Addressing the free radical tissue damage manifesting as oxidative stress is the novel approach of antioxidants. Topical application of the polyphenol, antioxidant combination phloretin, and ferulic acid has been shown to neutralize free radical activity, enhance wound healing, and increase the number of tissue-building fibroblasts (AO ProVantage®, PerioSciences).
Patients with periodontitis have a chronic inflammatory response, which results in chronic oxidative stress. It is the chronic oxidative stress and associated tissue damage that is linked to systemic inflammatory conditions such as vascular disease.
Antioxidants provide a novel way of addressing oral diseases and conditions such as lichen planus, xerostomia, gingivitis, periodontitis, and aphthous ulcers. Incorporating research-based new technologies into our treatment plans enables us to enhance the care we provide for patients in and beyond their oral cavities.
Richard Nagelberg, DDS, has practiced general dentistry in suburban Philadelphia for more than 30 years. He is a speaker, advisory board member, consultant, and key opinion leader for several dental companies and organizations, and he lectures on a variety of topics centered on understanding the impact dental professionals have beyond the oral cavity. Contact him at [email protected].
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