TERM PAPER
SUB: Advanced Microbiology
TOPIC:-Dental caries Streptococcus mutans : microflora
Introduction :
Dental caries is a disease of modern society, associated with diet containing high proportion of carbohydrates. It has be known from hundred years that mixture of sugars with saline in the presence of acidogenic bacteria of the mouth especially Streptococci causes dental caries . Tooth decay is an ancient disease dating far into prehistory. The increase of caries during the Neolithic period may be attributed to the increase of plant foods containing carbohydrates . The beginning of rice cultivation in south Asia is also believed to have caused an increase in caries. A Sumerian text from 5000BC describes a tooth worm as the cause of caries . Evidence of this belief has also been found in India , Japan and China . The rate of caries remained low through the bronze and iron ages . Treatment consisted mainly of herbal remedies and charms. The barber surgeon of the time provided services that included tooth extractions . Learning their training from apprenticeships , these health providers were quite successful in ending tooth pain and likely prevented systemic spread of infections in many cases .
Muslim physicians provided the earliest known treatments for caries , though the also believed that it was caused by tooth worms like what the ancients believed .This was eventually proven false in 1200 by another Muslim dentist named Gaubari , was the first who reject the idea of caries being caused by tooth worms and he stated that tooth worms in fact do not even exist . The theory of the tooth worm was thus no longer accepted in the Islamic medical community from the 13th century onwards . During the European Age of Enlightenment , the belief that a tooth worm caused caries was also no longer accepted in the European medical community .
Pierre Fauchars , known as the father of modern dentistry , was one of the first to reject the idea that worms caused tooth decay and noted that sugar was detrimental to the teeth and gingival . In 1850 , another sharp increase in the prevalence of caries occurred and is believed to be a result of widespread diet changes . Prior to this time , cervical caries was the most frequent type of caries , but increased availability of sugar cane , refined fluor , bread and sweetened tea corresponded with a greater number of pit and fissure caries . In the 1890 W.D.Miller conducted a series of studies that led him to propose an explanation for dental caries that was influential for current theories . He found that bacteria inhabited the mouth and that they produced acids which dissolved tooth structures when in the presence of fermentable carbohydretes . This explanation is known as the chemo parasitic caries theory . Miller’s contribution , along with the research on plaque by G.V.Black and J.LWilliams , served as the foundation for the current explanation of the etiology of caries . Major Fernande E. Rodriguez Vargas first scientist who discovered micro-organism causes dental caries in the 1921 .Dental caries are cavities in teeth .(Wikipedia)
Cavities are caused by decay that spreads to inside the tooth . Although many bacteria present in mouth cause dental caries , but Streptococcus mutans is most commonly found in dental caries .Streptococcus mutans is a regular component of normal oral flora of humans which occurs in large numbers . It readily colonizes tooth surfaces . It contains the enzyme glycosyl transeferase that polymerizes glucose obtained from dietary sucrose to glucans which leads directly to the formation of plaque . Streptococcus produces more lactic acid than other bacteria and is more tolerant than most other Streptococci . It stores polysaccarides made from dietary sugars which can be utilized as reserve carbon and energy sources for production of lactic acid . The extracellular glucans formed by Streptococcus mutans are bacterial capsular polysacarieds that function as carbohydrate reserve . The organism can also form intracellular polysaccharides from sugars which are stored in cells and then metabolized to lactic acid . Dental caries occur when the outside covering of tooth known as enamel is break down . Streptococcus mutans use glucose , sucrose and fructose . Bacteria converted these sugars into lactic acid . This acid decreases the pH at the surface of tooth . As a result the enamel minerals dissolves . And as the pH falls below 5.5 , demineralization becomes faster than remineralizaton . This causes holes and cavities in the tooth . The decay spread inward into dentin followed by enamel demineralization to the pulp causes pulpitis . Once a cavity form , the lost tooth structure can not be regenerated .
The tooth has chalky white spot on the surface which shows demineralization of enamel . This spot changes into brown color and lead to cavitation . The brown color tooth shows dental caries . The affected area of tooth feel soft when touch . There is pain in tooth when get contact to heat , cold or sweet foods and drinks . The pain may be in whole mouth or one part . The person can not chew or bite food , as pain becomes worse . There may be fever . The gums get swollen .(wikipedia)
Methodology :
Dentist examine the tooth when patient goes to dentist clinic and complaints pain in tooth . Dentist do primary examination by seeing whether there is spot formation or cavity formation under a good light source . The transllumination method is used to see the color changes in tooth . In this method , the decayed tooth is appeared as shadows . X-ray image is taken to see the presence and extent of decay . Formation of cavities can be seen by naked eye but smaller carious lesions are difficult to examine. So , X-rays are very useful for smaller carious lesions . Sometimes Streptococcus mutans penetrate the enamel and reaches to the dentin , but then the outer surface may remineralized . These caries are known as hidden caries and this hidden caries is also diagnosed by using X-rays . It is suggested that the person should visit the dentist at least once in a year and the baby must carried on dentist visit once up to age one year . Then regular checkup after every six months . (Wikipedia)
Destroyed tooth structure does not fully regenerate but treatment of decay tooth preserve the tooth structure and prevent further destruction of tooth . Now a days , the treatment is less painfull and less expensive than the previous years . Sometimes the younger children put on general anesthesia , nitrous oxide , during dental treatment procedures due to age , behavior or severity of treatment . All the decayed material removed from the tooth and shapes the cavity by using dental instruments seems spoon like appearance . When decayed material is removed , the lost tooth structure requires replacement to return to functionality condition . The tooth is filled with replacement material known as restorative material . Restorative materials may be amalgam , composite resin , porcelain and gold . Fillings are not done in small children as the small size of teeth and the concern of recurrent decay . When the decay is too extensive and there may not be enough tooth structure remaining to use restorative material . In these type of cases , a artificial crown is used . This crown is made of gold or porcelain . This crown is like a cap which fitted over the remaining natural tooth .
In some cases root canal theray is applied on tooth . Root canal therapy is applied where the infection is occur in pulp and pulp get completely destroyed . The pulp of tooth and dead material is removed by using instruments . Then the canal is clean and shaped . Then a rubber like material known as guutta percha is used to fill the canaled tooth and crown is placed as patient desired . If the decay tooth condition is worse , that no above treatment can perform , then dentist suggest extraction of tooth . Sometimes extractions also preffered by patients due to wealth problem or problem during restoring the tooth . But the pulling of tooth is not done in children because pulling affects on alignment and spacing of permanent tooth when they come in . The another treatment is getting passively immunized individuals against Streptococcus mutans by rinsing with solution containing monoclonal antibodies . These passively immunized individual shows less Streptococcus mutans orally as compared to non-immunized individuals which rinsing with salie .(wikipedia)
Results and Discussion :
Sodium bicarbonate and Hydrogen peroxide : The effect on the growth of Streptococcus mutans :This experiment studied the effects of sodium bicarbonate and hydrogen peroxide on the cariogenic bacteria Streptococcus mutans through analysis with a spectrophotometer . The growth of Streptococcus mutans was analyzed using seven different environments . Twelve well in each of the seven rows of a multi-well plate were used to incubate the test material . In combinations of 10ul distilled water , 100ul broth , 10ul 10%sucrose , 10ul Streptococcus mutans , 10ul 10% sodium bicarbonate and 10ul 3% hydrogen peroxide , seven different environments were created for testing . Environments had either sodium bicarbonate or hydrogen peroxide with Streptococcus mutans or a combination of sodium bicarbonate and hydrogen peroxide with Streptococcus mutans . The plate was incubated and measured at 0 , 18 , 20 , 22 , 24 , 26 , 28 , 30 and 42 hours by optical density with a spectrophotometer . Results showed bacterial growth was prevented by sodium carbonate , hydrogen peroxide and the combination of sodium bicarbonate and hydrogen peroxide . Although hydrogen peroxide is bacteriocidal and sodium bicarbonate is bacteriostatic , there were no significant differences among the three treatment groups in spectrophotometer readings at any of the nine readings over42 hours . There was no significant difference among the effects of hydrogen peroxide , sodium bicarbonate or the sodium bicarbonate and hydrogen peroxide as measured by optical density . The hydrogen peroxide , sodium bicarbonate and sodium bicarbonate and hydrogen peroxide combination prevented growth of Streptococcus mutans . The result show that products containing these agents have the ability to stop the growth of Streptococcus mutans. Products containing sodium bicarbonate and/or hydrogen peroxide may be useful to caries-prone patients . (Wikipedia)
It is easier and less expensive to prevent tooth decay than to treat it . Preventative measures include frequent brushing and flossing to prevent plaque build up . A diet rich in calcium and fluoride in the water lead to stronger tooth enamel . A diet of more complex carbon hydrates that no sucrose snacks between meals is also a good preventative measure The four major prevention strategies are proper oral hygiene , fluoride , sealants and attention to diet . In oral hygiene the best way to prevent tooth decay is to brush the teeth at least twice a day , preferably after every meal and snack and floss daily . Cavities develop most easily in spaces that are hard to clean . Flossing once a day helps prevent gum disease by removing food particles and plaque at and below the gum line , as well as between teeth . Patients should visit their dentist every six months for oral examination and professional cleaning . Parents can easily prevent baby tooth decay by not allowing a child to fall asleep with a bottle containing sweetened liquids . If bottle is necessary when the child is falling asleep it should be filled only with plain , unsweetened water . After the eruption of the first tooth , parents should begin routinely wiping the infant’s teeth and gums with a moist piece of gauze or a soft cloth .Parents may begin brushing a child’s teeth with a small , soft tooth brush at about two years of age , when most of the primary teeth have come in . They should apply only a very small amount , the size of a pea , of toothpaste containing fluoride .Too much fluoride may cause spotting fluorosis of the tooth enamel .
Fluoride is a natural substance that slows the destruction of enamel and helps to repair minor tooth decay damage by remineralizing tooth structure . Toothpaste mouth wash , fluoridated public drinking water and vitamine supplements are all possible source of fluoride . Children living in areas without fluoridated water should receive 0.25mg/day of fluoride before age three , 0.5mg/day of fluoride from threeto six years of age and 1mg/day after age six . Sometimes children can also have their teeth treated with fluoride at the dentist’s office . Because fluoride is most beneficial on the smooth surfaces of teeth . Sealants were developed to protect the irregular surfaces of teeth .A sealant is a thin plastic coating that is painted over the grooves of chewing surfaces to prevent food and plaque from being trapped there . Sealant treatment is painless , because no part of the tooth is removed , although the tooth surface is etched with acid so that the plastic will adhere to the rough surface . Sealants are usually clear or tooth colored , making them less noticeable than silver fillings . They cost less than fillings and can last upto ten years , although they should be checked for wear at every dental visit . Children should get sealants on their first permanent six year molars which come in between the ages of five and seven and on the second permanent twelve year molars which come in between the ages of eleven and fourteen . The risk of tooth decay can be lowered by choosing foods wisely and eating less often . Foods high in sugar and starch to produce the acid that destroys the enamel . The damage increases with more frequent eating and longer periods of eating . For better dental health children should eat a variety of foods limit the number of snacks , avoid sticky and overly sweetened foods and brush often after eating . Drinking water is also beneficial for rinsing food particles from the mouth . Children can be taught to rinse their mouth out with water after eating if they are unable to brush after lunch at school .
Dental caries can be prevented by making the tooth less susceptible to acid attack , removing cariogenic bacteria from the teeth and limiting agestion of cariogenic substrate . It has been found that milk and certain types of cheese like cheddar can help counter tooth decay if eaten soon after the consumption of foods potentially harmfull to teeth . Also chewing gum containing xylitol a wood sugar is widely used to protect teeth in some countries , being especially popular in the Finnish candy industry . Xylitol’s effect on reducing plaque is probably due to bacteria’s inability to utilize it like other sugars . Chewing and stimulation of flavor receptors on the tongue are also known to increase the production and release of saliva , which contains natural buffers to prevent the lowering of pH in the mouth to the point where enamel may become demineralized . (Wikipedia)
Conclusion:
The diet enriched in sugars is responsible for dental caries . Daily brushing to teeth prevent from dental caries. Always clean mouth after eating food , snacks or anything with unsweetened water. Use fluoride drinking water.
References:
1. http://72.14.235.132/search?q=cache;Kpr3E-t-5Ni4J;en,wikipedia.org/wiki/Tooth_decay+caries+site;wikipedia.org&hl=en&ct=clnk&cd=1&gl=in
2. http://www.answers.com/topic/Tooth_decay
3. http://72.14.235.132/search?q=cache;iLaJj4E3qIMJ;www.dentalgentlecare.com/tooth_decay.htm+tooth+decay&hl=en&ct=cln&cd=in
http://www.web-books.com/eLibrary/Medicine/Mou
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