Disease in the oral cavity, especially periodontal disease, is largely the result of infection. Killing off the pathogens is only part of the treatment oral disease, but the challenge remains of eliminating inflammation—which has been shown to be the common bad actor in in oral and systemic disease and may in fact be the link between the two.
In periodontitis, bacteria such as porphyromonas gingivalis trigger the release of cytokines, chemokines, prostaglandins, and enzymes that start the inflammatory process by signaling for an increase in white blood cells—polymorphonuclear neutrophils (PMNs). Inflammation is the body’s response to attack, but as PMNs attack the bacteria, they release additional cytokines that increase the levels of reactive oxygen species (ROS). This heightens oxidative levels and sets the stage for oxidative stress and cell damage in the gingival tissue, periodontal ligament and alveolar bone.
Controlling or eradicating the bacteria is a basic therapeutic strategy for periodontal disease. Various antibacterial agents and drugs are indicated, whether they be ingested, used in rinses or applied topically to the affected tissues.
Saliva also contains natural antibacterial compounds, including thiocyanate, hydrogen peroxide and immunoglobulin Thus, it presents a natural defense system against bacteria and other micro-organisms.
The Challenge of Inflammation
Eradicating pathogens addresses one aspect of treating oral disease. Controlling inflammation is another. Besides infection, there are several other causes for inflammation in the oral cavity. Underlying conditions such as diabetes, rheumatoid arthritis, poor nutrition, cardiovascular disease or other illness may heighten the inflammation throughout the system. Stress, poor diet and lack of exercise are also implicated.
External substances such as alcohol or nicotine also lead to inflammation in the oral cavity. The metals, resins and other materials used in dental procedures can cause inflammation, as can tooth whitening compounds.
All of these substances and conditions cause an increase in free radical molecules, including ROS. The accumulation of free radicals and ROS results in oxidative stress, inflammation, and the risk of cell damage.
Reducing the level of ROS and free radicals can reverse oxidative stress. Antioxidants are large, complex molecules that can bond with the unpaired electrons of free radicals, effectively neutralizing them.
In this way, antioxidants can interrupt the inflammatory pathway, whether the inflammation is the result of infection or systemic disease, or whether it results from dental procedures or even self-administered substances.
Saliva is rich in antioxidants, including uric acid, albumin, ascorbic acid, glutathione and antioxidant enzymes. However, active infection as well as toxic substances in the oral cavity can deplete the normal balance of antioxidants in saliva. Just as extra antibacterial agents bolster the fight against pathogens, extra antioxidants resupply the arsenal in saliva.
Fighting oral disease requires a combined effort of antibacterials to wipe out the pathogens along with antioxidants to arrest the inflammatory process. Saliva, with its antibacterial and antioxidant capacities is part of a natural defense system. The addition of both antibacterial drugs and supplemental antioxidants assures the victory.