Ever since the dental profession has been around, dentists have been attempting to treat and inform people for prevention of cavities. Years of worldwide research has linked as many as two to three hundred different bacterial species to the production of the cavity causing bio-film called plaque. However only within the last few decades have they been able to completely link one specific bacteria, Streptococcus mutans, to the pathogenic cause of cavities The isolation of this particular bacteria has shown that the main product of its anaerobic fermentation is lactic acid, a very harmful substance to the outer surfaces of teeth.
Streptococcus mutans is a gram positive, anaerobic bacterium. Because it is anaerobic, it is mostly found between adjacent teeth or in the deep crevices on occlusal (the biting surface) of teeth. It is as mentioned before the main cavity and halitosis causing bacteria in the mouth (although there have been hundreds of other bacteria as well as other microorganisms identified). The entire genome of S. mutans of over two million base pairs has been completely identified and sequenced. This has proved to be a very useful scientific accomplishment because just recently the University of Florida’s Dr. Jeffrey Hillman has been able to engineer the genome of S. mutans so that when its fermentation is complete, lactic acid is not a product. To understand this, you must understand what a harmful substance such as lactic acid does to a human tooth.
When fermentation has run its course, lactic acid is secreted onto the surface of the hard outer shell surface of the tooth called the enamel. Because of enamel’s chemical makeup, which is made up almost entirely of minerals, about 90% calcium salts, is actually a fairly good defender against bacteria. However, because of the evolution of S. mutans to secrete lactic acid, the mineral salt concentration stands no chance and is broken down by the highly acidic fermentation by product. It has been widely accepted that this species of bacteria has been living with humans for thousands of years in harmony. But the implication of more and more refined sugar into man’s diet that led to what scientist believe was a “mutation” or evolution to digest this sugar, producing the harmful acids. So when lactic acid is secreted onto the enamel, it begins breaking down the mineral content leaving holes in the outer surface, then progressing into the inner surface of the tooth, the dentin. Once the dentin has been penetrated, defense is futile and further damage can progress.
It is believed that every single human has this bacteria already existing in their mouth. This means that the only prevention is to lessen the impact of the fermentation by product, lactic acid. This can be accomplished by brushing, flossing, and most effectively by reducing the intake of refined and processed sugars. These come in the form of sweets, colas, and processed powdered sweeteners. Studies have also shown that the use of a water mouth rinse can greatly reduce probability of cavities after the consumption of these sugars. Very few people are able to completely reduce the effects of S. mutans but there are options to attempt to control it.
Cavities may be the least of our worries though. Very recent groundbreaking studies have now linked oral bacteria caused diseases to more serious cardiovascular disease. The bacteria it seems tend to migrate into the bloodstream after they have caused penetrating damage to the teeth and gums. They then migrate to coronary arteries causing blood clots which restrict Oxygen and blood flow. Another process that occurs is the release of C-Reactive Proteins as a response by the liver to the presence of these bacteria in the bloodstream. The CRP induce clot formation and thickening of the artery walls. All of these processes can contribute to and ultimately lead to very serious cardiovascular problems. Although this discovery is very new and still requires numerous studies to be conducted to gain more knowledge, it is the opinion of many of today’s dentists that this could be an enormous focal point in the dental practices of the future. Because cardiovascular disease is such a huge contributor to morality rates in American men and women, the government has even expressed its desire to see the understanding and possible treatments of this problem furthered.
Whatever the future holds for this bacteria, there is one thing that we can be sure of, and that is that the bacteria itself will not be going away. What we do to prevent the damage that it potentially holds is yet to be determined. But whether it is genetic bioengineering of the bacterium genome to induce non harmful by products, or the prevention by more careful oral hygiene practices, the world is becoming all to aware that we must concern ourselves with my microbe of the week, Streptococcus mutans.
References
American Academy of Periodontology. 2004. The American Academy of Periodontology. Feb. 22, 2006. http://www.perio.org/consumer/mbc.heart.htm
Dental Disease as a Risk Factor for Cardiovasculoar Disease. 2006. Masel Books Feb. 22, 2006. http://wwwbracesinfocom/cardiovascular.htm
Dental Infections.2006. WebMD. Feb.19, 2006. http://wwwemedicinecom/emerg/topic128.htm
Roy Curtiss. “Genome sequence of Streptococcus mutans UA159, a cariogenic dental pathogen” PNAS vol. 99 (2002): pgs 1434-1439
Karamitsu, H.K. (2001) Current Issues in Molecualr Biology. 3, 35-36.
Quivey, R.G., Kunert, W.L. & Hahn, K. (2001) Critic Reiew of Oral Biological Medication. 12, 301-314.
Martin, E.JS. & Wittenberger, C.L. (1980) Infection Immunology. 28, 220-224
*Disclaimer - This report was written by a student participaring in a microbiology course at the Missouri University of Science and Technology. The accuracy of the contents of this report is not guaranteed and it is recommended that you seek additional sources of information to verify the contents.
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