Dental Caries Prevention by Camellia sinensis
Mary Barker
Tooth Decay
But the time the human mouth reaches maturity, most adult humans have thirty two teeth. At the front of the mouth are incisors, the sharpest teeth, that are used to bite food and direct the food into the mouth. The canine teeth are located behind the incisors on either side of the mouth. They have long roots and grasp incoming food. The pre molars are located even father back into the mouth. These teeth are wide and flat, equipped for grinding food before it is digested. Finally, the molars grind food into particles small enough to be swallowed and broken down in human’s digestive tracts.
It is very important to keep all of these teeth clean, and cavities are a real concern for humans in today’s society. After food enters the mouth, particles and bacteria are able to cling to the surface of the teeth. Many times, if the teeth are not brushed soon enough after eating, the bacteria can grow and form a film on the teeth.
Certain bacteria thrive in the conditions found in the human mouth. The warm environment and constant sources of food both make the teeth and gums ideal locations for bacterial cultures to grow. Streptococcus mutans and Streptococcus sobrinus are two such bacteria commonly found in dental cavities. When they grow on the surfaces of teeth, they eat at the food and release acid as a waste product.
This acid eventually builds-up, and breaks down the minerals in the teeth. Over time, when large amounts of acid have been released surrounding teeth, cavities begin to form. The acid initially leaves the surface of the tooth intact, while breaking down the enamel lying beneath the surface. When the tooth has enough damage, the surface also breaks down and a cavity is formed.
The most common means to teeth decay prevention is to consistently brush and floss the teeth. Flouride is usually present in toothpaste as a means to breakdown bacteria and prevent acid build-up. In some areas, fluoride is also present in the public drinking water, although this is a topic of much debate recently [1]. Flouride is also present in green and black tea, one reason why drinking tea can prevent tooth decay.
Bacterium Causing Tooth Decay
Ancient Japanese folklore tells how drinking tea leads to long life and clean teeth. At least the second part of this fable seems to be true. Recent research indicates that tea is able to counter some of the microorganisms, Streptococcus mutans, Streptococcus sobrinus, and Lactobacillus that can form plaque and biofilms on teeth, resulting in tooth decay.
Microorganisms from the genus Streptococcus are gram-positive bacteria. They have a round shape and frequently grow in chains. They are anaerobes that thrive in a complex culture. Streptococcus can cause many diseases, ranging from strep throat, to necrotizing fasciitis (flesh-eating disease) to the more mild tooth biofilm build-up. Although not the most dangerous inflictions caused by this genus, here the focus is on the latter condition and how to prevent it.
Streptococcus mutans is a species of Streptococcus that usually resides in the human. mouth It was discovered in 1924 by J K Clark and has recently been a topic of study due to several hundred unique genes that the bacteria has. These genes could potentially be a targeted in an attempt to kill the bacteria that cause tooth decay. S mutans is able to cling to the surface of teeth and feed on food particles, especially carbohydrates, that become trapped on and between teeth. The acid released by this bacteria is the leading cause of tooth decay in the world.
Streptococcus sobrinus is closely related to S. mutans, although it is less common in human beings. The two bacterial species are very similar and can only be distinquished with advanced technology and testing. In one study, the varying species were obtained through plaque samples, amplified, and detected by PCR in a collection of school aged children. S. mutans was found 72.8% of the children tested, while S. sobrinus was only found in 61.1% of the subjects. [3]
Although S. mutans may be more common in the mouth, it has been shown that S. sobrinus has a greater impact on tooth decay. Students having both species had a significantly higher level of tooth decay than those with only S. mutans. The children with the most decay had both S. mutans and S. sobrinus present on their teeth.
Lactobacillus are also a gram positive bacteria. They are organotrophs that develop in a rod-like shape. They can sometimes grow in clusters, and are especially prominent in tooth biofilm, where they thrive in the high sugar conditions. Lactobacillus’ main source of energy is found from metabolizing sugars into lactic acid, a process that makes them prime candidates for mouth dwellers.
Tea
Include some current research in each topic, with at least one figure showing data.
Effects of Tea on Dental Caries
Looking at the molecular processes involved in teeth decay can help explain the nature of dental caries prevention. Dental caries is a gradual process that begins with the accumulation of bacteria in the mouth, usually caused by prolonged exposure of the teeth and mouth to sucrose. This process has three basic steps.
1. Bacteria, usually from a food source, attached to the teeth.
2. Glycocalyx is formed when glucosyl transferase, a bacterial enzyme, reacts with sucrose
3. Formation of biofilm, as bacteria metabolize carbohydrates and produce acid that eventually decays the tooth.
Green, black, and oolong teas have specifically been studied in relation to teeth health. Green and black tea share many similarities, yet differ slightly in the structure of their catechins. Green tea has simple catechins with a lower molecular weight than black catechins. Many black catechins have been oxidized through fermentation and have a higher molecular weight, although some remain simple. [5] Catechins can remain in the mouth for up to sixty minutes after tea has been consumed. A cup of green tea contains three times as many catechins than a brewed cup of black tea. [5]. Oolong tea is an intermediate between these two types, containing both simple and fermented catechins. There have been many studies exploring the molecular methods behind the ability of tea to fight tooth decay. It has been discovered that these teas actually attack each of the three basic steps to dental caries. The first step is the adhesion of the bacteria to the tooth. Green and black tea extracts inhibits the ability of S. mutans to bind to the tooth surface. In addition, Oolong extracts have been found to have an affinity for proteins. When the oolong binds to the surface proteins of the tooth, they prevent other bacteria from attaching there as well. [5] The second step of tooth decay involves the production of glycocalyx, a sugar coat produced from oral bacteria. Green and black tea contains catechins that reduce the level of enzyme activity in glucosyl transferase. This lowers glycocalyx levels on the tooth. Green, and especially black tea have been found to prevent salivary amylase in S. mutans. The catechins in black tea, epigallocatechin gallate (EGCG) having a heavier molecular weight are especially detrimental to amylase activity. This is caused by the ability of EGCG to breakdown the membranes of the oral bacteria. There is not a substantial amount of evidence concerning the specific reasons that tea is able to harm the bacteria in the human mouth. It has been found, however, that in trials in which tea was incorporated in the diets of certain animals, rats and hamsters specifically, there was a reduction in the amount caries on the teeth surfaces.
As previously mentioned, fluoride is a common means of dental caries prevention. Fluoride is found in the leaves of tea, especially green and black. When tea is brewed, the extracts are dissolved into the liquid and consumed with the drink. This fluoride can cling to teeth and fight the acid build-up caused by bacteria.
• Green and Black Tea prevents clinging on s mutans to teeth like surface.
• Extracts from oolong tea bound to bacterial surface proteins decreasing their fear of water, and increasing cellular aggregation
• Tea catechins inhibit the enzyme activity of glucosyl transferace
• Tea inhibits salivary amylase
• Suppressed amylase activity from S mutans
• EGCG (epigallocatechin gallate) may break up the membranes of bacteria
• EGCG also attracts proteins- used in many ways by the
Conclusion
Overall paper length should be 3,000 words, with at least 3 figures.
References
Edited by student of Joan Slonczewski for BIOL 238 Microbiology, 2009, Kenyon College.
