Dental caries

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3

Introduction

4

The aim of the study

5

Review

6

Subjects and Methods

17

Result

18

Discussion

30

Conclusion

33

Obstacles

34

Recommendation

35

References

37

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Acknowledge

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Contents


Acknowledge Prof.Dr. Mahmoud Abou-Salem Dr. Ghadeer Maher

Research team Arranged Alphabetically

Alshimaa Saleh Asmaa Abdallah Asmaa Magdi Eman Tamer Hasnaa Wageeh Ibrahim Kandeel Islam Shedeed Marwa Hosam Menna Taha Miral Ahmed

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Naglaa Sobhi

Head of the Department Research Supervisor


Recent trends in the use of bottled versus fluoridated tap water and dietary changes may be responsible. The caries increases and disparities could be brought about from changes in world demographics. The influx of immigrants has been occurring in Europe, the United States, and Asia. Changes in oral health are occurring due to shifts in populations. The large movements of rural people to urban centers in search of new manufacturing jobs in Asia and other countries have spawned entire cities. These populations have left the rural farming life for urban labor with the attending negative changes in diet, lifestyle and health. (Marthaler, TM. Changes in dental caries 1953-2003) various measures of low socioeconomic status (SES) older age, prior experience of decay in the primary dentition associated with caries experience in the permanent dentition female sex presence of abnormalities, hypoplasias, or enamel defects as well as low level of parental education and cariogenic diet all affect caries risk . ( Scand J Dent Res 1990)

This wider meaning of oral health does not diminish the relevance of the two globally leading ,oral afflictions - dental caries and periodontal diseases. Both can be effectively prevented and controlled through a combination of community, professional and individual action. )Ann Periodontol 1998) The factors to be considered in relation to the decline in caries are changes in sugar consumption, improved oral hygiene, fluorides in toothpaste, fluoride rinsing and other school based preventive programs. The other extreme comprises many of the developing countries where the consumption of sugar products, sweets, confectionaries and soft drinks is growing fast( Community Dent Oral Epidemiol 1982) . The unresolved severe problems of periodontal disease, which have for a long time characterized most of the developing countries, are now compounded by a rapidly escalating prevalence of dental caries .An increase in the prevalence and severity of caries has been reported, first in the upper income groups, then in the urbanized populations, followed by changes in disease prevalence in the rural groups. (. Int Dent 7 1981)

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Dental caries is widely recognized as an infectious disease induced by diet. The main players in the etiology of the disease are; a) cariogenic bacteria, b) fermentable carbohydrates, c) a susceptible tooth and host and d) time. However, in young children bacterial flora and host defense systems are in the process of being developed, tooth surfaces are newly erupted and may show hypoplastic defects, and their parents must negotiate the dietary transition through breast/bottle feeding, first solids and childhood tastes. Thus it is thought that there may be unique risk factors for caries in infants and young children (Seow, 1998).

The interrelationship between oral and general health is proven by evidence. Severe periodontal disease, for example, is associated with diabetes. The strong correlation between several oral diseases and non-communicable chronic diseases is primarily a result of the common risk factors. Many general disease conditions also have oral manifestations that increase the risk of oral disease which, in turn, is a risk factor for a number of general health conditions.

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Introduction


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Research in industrialized countries has revealed that children of high social class families experience Methods less caries than those of lower social classes However, this relationship appears to be reversed in the developing countries. These variations in caries experience and the periodontal condition in various socioeconomic groups are usually explained by differences in dental habits, sugar consumption, use of fluoride in its various forms, and oral hygiene practices.( Community Dentistry and Oral Epidemiology 1981).

The Aim of the Present Study The aim of the present study was to determine the prevalence of dental caries among preparatory school children in rural and urban area and risk factors of dental caries .The association of dental caries experience with socioeconomic variables was also tested.


Review

better hygiene

practices

and

measures

such

as

Introduction

tooth decay continue to have a disparity in

Caries is the medical term for the infectious process that, if untreated, can progress to a cavity. A vast majority of people in the United States have at least 1 cavity by adulthood. In fact, dental caries is the most common chronic disease of childhood, affecting:

children in the United States and Europe,

preventive fluoride

treatment. Nonetheless, countries that have experienced an overall decrease in cases of the distribution of the disease. Among twenty percent of the population endures sixty to eighty percent of cases of dental caries. A similarly skewed distribution of the disease is found throughout the world with some children having none or very few caries and

58.6% of all 5- to 17-year-olds

51.6% of elementary school students (5 to 9 years old)

77.9% of 17 year-olds

84.7% of adults

others

having

a

high

number.

Australia, Nepal, and Sweden have a low incidence of cases of dental caries among children, whereas cases are more numerous in Costa Rica and Slovakia. The

classic DMF

(decay/missing/filled)

index is one of the most common methods

Dental caries are 5 times more common than asthma (11%) and disproportionately affect poor and minority populations.

for assessing caries prevalence as well as

Epidemiology

mirror and cotton rolls. Because the DMF

Worldwide,

approximately

dental treatment needs among populations. This index is based on in-field clinical examination of individuals by using a probe,

2.43 billion

people (36% of the population) have dental caries in their permanent teeth. In baby teeth it affects about 620 million people or 9% of the population. The disease is most prevalent in Latin American countries, countries in the Middle East, and South Asia, and least prevalent in China. In the United States,

dental

caries

is

the

most

common chronic childhood disease, being at least five times more common than asthma. It is the primary pathological cause of tooth loss in children. Between 29% and 59% of

index is done without X-ray imaging, it underestimates real caries prevalence and treatment needs.

Etiology The development of caries is dependent on the interaction of four primary factors. These are a host (tooth surface), a substrate (food), the presence of oral bacteria, and time. Caries will not develop if any of these four primary factors are not present. Each of the four primary factors can be further divided into sub-factors that also influence the likelihood of caries.

developed countries, and this decline is usually

attributed

to

increasingly

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The number of cases has decreased in some

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adults over the age of fifty experience caries.


Figure 1. The factors and sub-factors that influence caries development.

tooth-strengthening nutrients is consumed, and/or the buffering capacity of saliva is high. 2.

When food is retained in the mouth after eating and not actively removed after eating, is consumed more frequently, and/or more sugars, sucrose-containing foods, and sticky foods (like toffee) are consumed, there is higher risk of caries. On the other hand, when remaining food particles are actively removed after eating, food is consumed less frequently, fewer sugars, sucrose-containing foods, and sticky foods are consumed, and/or more tooth-cleaning foods (like apples) are eaten, the likelihood of caries is lower.

Adapted from: Selwitz RH, Ismail AL, Pitts NB. Dental caries. Lancet. 2007;369:51-59.

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1.

Host (tooth surface): The subfactors that influence caries development are age (the enamel of the deciduous teeth of children is more susceptible to acid demineralization), if fluoride has been used, tooth morphology (which varies within the mouth and from person to person), root surface exposure due to gum recession, nutrition (if tooth-strengthening nutrients are consumed), and saliva flow rate and buffering capacity. A tooth is more susceptible to caries if it has less acid resistant enamel due to age or low fluoride intake, or if the roots have been exposed by gum recession. Caries risk is also higher if the diet is low in nutrients (such as magnesium and vitamin D) that are necessary for healthy tooth development, and/or when an individual’s saliva flow rate is low or has a low buffering capacity. Pit-and-fissure demineralization is more likely to develop in teeth with numerous and exaggerated grooves. Teeth are less prone to caries activity in situations where tooth enamel has been strengthened by fluoride, a diet of

Substrate (food): The sub-factors that influence caries development are oral clearance(if food is retained or not in the mouth after eating), oral hygiene (if, after eating, food is actively removed with a sharp instrument such as a toothpick), eating frequency, food detergency (if consumed food can clean teeth), consumption of carbohydrates, and the carcinogenicity of consumed carbohydrates (sucrose is more cariogenic than glucose and fructose).

3.

Oral bacteria: The development of caries depends on microbial load (how much bacteria is present), plaque composition (with some types of plaque microbes being more cariogenic than others), plaque acidogenicity (how much acid can be produced by the plaque that is present), plaque acidoduricity (how well plaque can survive in acidic conditions), oral hygiene (how often microbial load is reduced by brushing or prophylaxis), and if fluoride is present in plaque. The likelihood of caries development is higher when microbial load is high as indicated by excessive plaque, when more caries-linked bacteria are present in plaque, when plaque produces more acid, when more plaque bacteria can


Time: While the shift in microflora can occur over a fairly short period, a significant amount of time is needed for demineralization to lead to the development of whitespot and/or carious lesions. Acid production does not instantly trigger tooth decay, and in the early stages, remineralization can restore enamel, keeping the effects of dental caries at bay.

In summary, bacterial fermentation of consumed sugars produces acid in the tooth’s immediate environment. This acid demineralizes tooth enamel, and over time, this dissolution of tooth structure leads to the development of carious lesions. Because the combination of factors and sub-factors include unavoidable situations, dental caries can be very difficult to prevent.

Bacteria collect on the teeth and along the edge of the gums in a cream-colored mass called plaque (figure 2). The bacterial deposits that form plaque on teeth differ considerably from that on soft tissues because teeth are a non-shedding surface, allowing more time for the development of a “structure” consisting of multiple layers of bacteria. This plaque “structure” also serves as a biofilm, typically defined as an aggregate of microorganisms in which cells adhere to each other and/or to a solid substrate exposed to an aqueous surface. The bulk of the volume (~90%) of dental plaque biofilm is comprised of gel-like matrix of extracellular polysaccharides produced by oral bacteria–

Figure 2. Dental plaque deposits.

From: V. Kim Kutsch, DDS. Originally published in Inside Dentistry, 2009;5(5):6065.

Pathophysiology Enamel Enamel is a highly mineralized a cellular tissue, and caries act upon it through a chemical process brought on by the acidic environment produced by bacteria. As the bacteria consume the sugar and use it for their own energy, they produce lactic acid. The effects of this process include the demineralization of crystals in the enamel, caused by acids, over time until the bacteria physically penetrate the dentin. As the enamel loses minerals, and dental caries progresses, the enamel develop several distinct zones, visible under a light microscope. From the deepest layer of the enamel to the enamel surface, the identified areas are the: translucent zone, dark zones, body of the lesion, and surface zone.

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4.

these polysaccharides are what holds the biofilm together and triggers changes that make it increasingly difficult to remove over time: When a cell becomes a component of biofilm, one of the many changes it experiences is a shift in gene expression that makes it up to 1,000 times more resistant to antibodies, antibiotics, and antimicrobial compounds than its planktonic (single cell) counterparts.

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survive in acidic conditions, and/or when plaque is not regularly removed by brushing. The odds that caries will develop are lower when the microbial load is low as indicated by little plaque, present plaque has fewer bacteria associated with caries or that can withstand very acid conditions, plaque acid production is low, and/or plaque is regularly removed by brushing or flossing.


Dentin

into the tooth. The tubules also allow caries

Unlike enamel, the dentin reacts to the progression of dental caries. After tooth formation, the ameloblasts, which produce enamel,

are

destroyed

once enamel

to progress faster .The fluid inside the tubules

bring immunoglobulins from

the immune system to fight the bacterial infection

formation is complete and thus cannot later

Fluids within dentinal tubules are believed to

regenerate enamel after its destruction. On

be the mechanism by which pain receptors

the

dentin

is

are triggered within the pulp of the tooth.

throughout

life

Since sclerotic dentin prevents the passage of

by odontoblasts. Since odontoblasts are

such fluids, pain that would otherwise serve

present, a stimulus, such as caries, can

as a warning of the invading bacteria may not

trigger a biologic response. These defense

develop at first. Consequently, dental caries

mechanisms

may progress for a long period of time

other

hand,

produced continuously

include

the

formation

of

without any sensitivity of the tooth, allowing

sclerotic and tertiary dentin. In dentin from the deepest layer to the

for greater loss of tooth structure.

enamel, the distinct areas affected by caries

Tertiary dentin

are the advancing front, the zone of bacterial

In response to dental caries, there may be

penetration, and the zone of destruction. The

production of more dentin toward the

advancing front represents a zone of

direction of the pulp. This new dentin is

demineralized dentine due to acid and has no

referred to as tertiary dentin. Tertiary dentin

bacteria present. The zones of bacterial

is produced to protect the pulp for as long as

penetration and destruction are the locations

possible from the advancing bacteria. As

of invading bacteria and ultimately the

more tertiary dentin is produced, the size of

decomposition of dentin. The zone of

the pulp decreases.

destruction has a more mixed bacterial population where proteolytic enzymes have

Cementum

destroyed the organic matrix. The innermost

The incidence of cemental caries increases in

dentine caries has been reversibly attacked

older adults as gingival recession occurs from

because the collage matrix is not severely

either trauma or periodontal disease. It is a

damaged, giving it potential for repair. The

chronic condition that forms a large, shallow

outer more superficial zone is highly infected

lesion

with proteolytic degradation of the collagen

root’s cementum and then dentin to cause a

matrix and as a result the dentine is

chronic infection of the pulp . Because dental

irreversibly demineralized.

pain is late , many lesions are not detected

Sclerotic dentin

early, resulting in restorative challenges and

and

slowly

increased tooth loss. The structure of dentin is an arrangement of tubules. The

carious

called process

dentinal continues

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channels,

through the dentinal tubules, which are

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microscopic

resulting from the progression of caries deep

responsible for the triangular patterns

invades

first

the


Signs and symptoms

lesion, an incipient carious lesion or a "microcavity". As the lesion continues to demineralize, it can turn brown but will eventually turn into a cavitation ("cavity"). Before the cavity forms, the process is reversible, but once a cavity forms, the lost tooth structure cannot beregenerated. A lesion that appears dark brown and shiny suggests dental caries were once present but the demineralization process has stopped, leaving a stain. Active decay is lighter in color and dull in appearance. As the enamel and dentin are destroyed, the cavity

becomes

more

noticeable.

The

affected areas of the tooth change color and become soft to the touch. Once the decay (A) A small spot of decay visible on the surface of a tooth. (B) The radiograph reveals an extensive region of demineralization within the dentin (arrows). (C) A hole is discovered on the side of the tooth at the beginning of decay removal. (D) All decay removed. Tooth decay may not cause symptoms until it has reached an advanced stage. This is why it is important to have regular dental checks. Tooth decay is much easier to treat successfully in its early stages. Adults over 18 should have a check-up at least once every two years. People under the age of 18 should have a check-up at least once a year. Young children may require a check-up every 4-6 months. However, your dentist may recommend more frequent check-ups if you have had a history of dental problems, or you are thought to be at a higher risk of developing tooth decay.

passes through enamel, the dentinal tubules, which have passages to the nerve of the tooth, become exposed, resulting in pain that can be transient, temporarily worsening with exposure to heat, cold, or sweet foods and drinks. A tooth weakened by extensive internal decay can sometimes suddenly fracture under normal chewing forces. When the decay has progressed enough to allow the bacteria to overwhelm the pulp tissue in the center of the tooth a toothache can result and the pain will become more constant. Death of the pulp tissue and infection are common consequences. The tooth will no longer be sensitive to hot or cold, but can be very tender to pressure. Dental

caries

breath and

can

foul

also tastes. In

cause bad highly

progressed cases, infection can spread from the tooth to the surrounding soft tissues. Complications such as cavernous sinus thrombosis and Ludwig angina can

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be life-threatening.

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A person experiencing caries may not be aware of the disease. The earliest sign of a new carious lesion is the appearance of a chalky white spot on the surface of the tooth, indicating an area of demineralization of enamel. This is referred to as a white spot


Diagnosis

The tip of a dental explorer, which is used for caries diagnosis.

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The presentation of caries is highly variable. However, the risk factors and stages of development are similar. Initially it may appear as a small chalky area (smooth surface caries), which may eventually develop into a large cavitation. Sometimes caries may be directly visible. However other methods of detection such as X-rays are used for less visible areas of teeth and to judge the extent of destruction. Lasers for detecting caries allow detection without ionizing radiation and are now used for detection of interproximal decay (between the teeth). Disclosing solutions are also used during tooth restoration to minimize the chance of recurrence. Primary diagnosis involves inspection of all visible tooth surfaces using a good light source, dental mirror and explorer. Dental radiographs (X-rays) may show dental caries before it is otherwise visible, in particular caries between the teeth. Large dental caries are often apparent to the naked eye, but smaller lesions can be difficult to identify. Visual and tactile inspection along with radiographs are employed frequently among dentists, in particular to diagnose pit and fissure caries. Early, uncavitated caries is often diagnosed by blowing air

across the suspect surface, which removes moisture and changes the optical properties of the unmineralized enamel. Some dental researchers have cautioned against the use of dental explorers to find caries, in particular sharp ended explorers. In cases where a small area of tooth has begun demineralizing but has not yet cavitated, the pressure from the dental explorer could cause a cavity. Since the carious process is reversible before a cavity is present, it may be possible to arrest the caries with fluoride and remineralize the tooth surface. When a cavity is present, a restoration will be needed to replace the lost tooth structure. At times, pit and fissure caries may be difficult to detect. Bacteria can penetrate the enamel to reach dentin, but then the outer surface may remineralize, especially if fluoride is present. These caries, sometimes referred to as "hidden caries", will still be visible on x-ray radiographs, but visual examination of the tooth would show the enamel intact or minimally perforated. The differential diagnosis for dental caries includes dental fluorosis and developmental defects of the tooth including hypomineralization of the tooth and hypoplasia of the tooth.

prevention Oral hygiene Personal hygiene care consists of proper brushing and flossing daily. The purpose of oral hygiene is to minimize any etiologic agents of disease in the mouth. The primary focus of brushing and flossing is to remove and prevent the formation of plaque or dental biofilm. Plaque consists mostly of bacteria. As the amount of bacterial plaque increases, the tooth is more vulnerable to dental caries when carbohydrates in the food are left on teeth after every meal or snack. A toothbrush can be used to remove plaque on accessible surfaces, but not between teeth or


Professional hygiene care consists of regular dental examinations and professional prophylaxis (cleaning). Sometimes, complete plaque removal is difficult, and a dentist or dental hygienist may be needed. Along with oral hygiene, radiographs may be taken at dental visits to detect possible dental caries development in high risk areas of the

Dietary modification For dental health, frequency of sugar intake is more important than the amount of sugar consumed. In the presence of sugar and other carbohydrates, bacteria in the mouth produce acids that can demineralize enamel, dentin, and cementum. The more frequently teeth are exposed to this environment the more likely dental caries are to occur. Therefore, minimizing snacking is recommended, since snacking creates a continuous supply of nutrition for acidcreating bacteria in the mouth. Also, chewy and sticky foods (such as dried fruit or candy) tend to adhere to teeth longer, and, as a consequence, are best eaten as part of a meal. Brushing the teeth after meals is recommended. For children, the American Dental Association and the European Academy of Paediatric Dentistry recommend limiting the frequency of consumption of drinks with sugar, and not giving baby bottles to infants during sleep (see earlier discussion). Mothers are also recommended to avoid sharing utensils and cups with their infants to prevent transferring bacteria from the mother's mouth. It has been found that milk and certain kinds of cheese like cheddar cheese can help counter tooth decay if eaten soon after the consumption of foods potentially harmful to teeth. Also, chewing gum containing xylitol (a sugar alcohol) is widely used to protect teeth in many countries now. Xylitol's effect on reducing dental biofilm is, it is presumed, 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

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However oral hygiene is probably more effective at preventing gum disease (periodontal disease) than tooth decay. Food is forced inside pits and fissures under chewing pressure, leading to carbohydratefueled acid demineralisation where the brush, fluoride toothpaste, and saliva have no access to remove trapped food, neutralise acid, or remineralise demineralised tooth like on other more accessible tooth surfaces food to be trapped. (Occlusal caries accounts for between 80 and 90% of caries in children (Weintraub, 2001).) Chewing fibre like celery after eating forces saliva inside trapped food to dilute any carbohydrate like sugar, neutralise acid and remineralise demineralised tooth. The teeth at highest risk for carious lesions are the permanent first and second molars due to length of time in oral cavity and presence of complex surface anatomy.

mouth, along with compliance to strict radiographic guidelines established by dental associations such as the American Dental Association and American Dental Hygienists' Association.

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inside pits and fissures on chewing surfaces. When used correctly, dental floss removes plaque from areas that could otherwise develop proximal caries but only if the depth of sulcus has not been compromised. Other adjunct oral hygiene aids includeinterdental brushes, water picks, and mouthwashes.


the point where enamel may become demineralized.

Common dentistry trays used to deliver fluoride.

fluoride is now more highly recommended than systemic intake such as by tablets or drops to protect the surface of the teeth. This may include a fluoride toothpaste or mouthwash or varnish. Many dental professionals include application of topical fluoride solutions as part of routine visits and recommend the use of xylitol and Amorphous calcium phosphate products.

Fluoride is sold in tablets for cavity prevention.

Other measures

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The use of dental sealants is a means of prevention. A sealant is a thin plastic-like coating applied to the chewing surfaces of the molars to prevent food from being trapped inside pits and fissures. This deprives resident plaque bacteria carbohydrate preventing the formation of pit and fissure caries. Sealants are usually applied on the teeth of children, as soon as the tooth erupt but adults are receiving them if not previously performed. Sealants can wear out and fail to prevent access of food and plaque bacteria inside pits and fissures and need to be replaced so they must be checked regularly by dental professionals. Calcium, as found in food such as milk and green vegetables, is often recommended to protect against dental caries. Fluoride helps prevent decay of a tooth by binding to the hydroxyapatite crystals in enamel. The incorporated calcium makes enamel more resistant to demineralization and, thus, resistant to decay. Topical

Vaccines are also under development.


Carious lesion

No treatment

Inactive lesion Active lesion

Existing filling

No treatment Noncavitated lesion

Nonoperative treatment

Cavitated lesion

Operative treatment

No defect

Defective filling

No replacement

Ditching, overhang

No replacement

Fracture Repair or or food replacement impaction of filling Inactive lesion Active lesion

No treatment Noncavitated lesion

Nonoperative treatment

Cavitated lesion

Repair or replacement of filling

An amalgam used as a restorative material in a tooth. Most importantly, whether the carious lesion is cavitated or noncavitated dictates the management. Clinical assessment of whether the lesion is active or arrested is also important. Noncavitated lesions can be arrested and remineralization can occur under the right conditions. However, this may require extensive changes to the diet

Once a lesion has cavitated, especially if dentin is involved, remineralization is much more difficult and a dental restoration is usually indicated ("operative treatment"). Before a restoration can be placed, all of the decay must be removed otherwise it will continue to progress underneath the filling. Sometimes a small amount of decay can be left if it is entombed and the there is a seal which isolates the bacteria from their substrate. This can be likened to placing a glass container over a candle, which burns itself out once the oxygen is used up. Techniques such as stepwise caries removal are designed to avoid exposure of the dental pulp and overall reduction of the amount of tooth substance which requires removal before the final filling is placed. Often enamel which overlies decayed dentin must also be removed as it is unsupported and susceptible to fracture. The modern decision-making process with regards the activity of the lesion, and whether it is cavitated, is summarized in the table. Destroyed tooth structure does not fully regenerate, although remineralization of very small carious lesions may occur if dental hygiene is kept at optimal level. For the small lesions, topical fluoride is sometimes used to encourage remineralization. For larger lesions, the progression of dental caries can be stopped by treatment. The goal of treatment is to preserve tooth structures and prevent further destruction of the tooth. Aggressive treatment, by filling, of incipient carious lesions, places where there is

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No carious lesion

(reduction in frequency of refined sugars), improved oral hygiene (toothbrushing twice per day with fluoride toothpaste and flossing), and regular application of topical fluoride. Such management of a carious lesion is termed "non-operative" since no drilling is carried out on the tooth. Nonoperative treatment requires excellent understanding and motivation from the individual, otherwise the decay will continue.

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Treatment


superficial damage to the enamel, is controversial as they may heal themselves, while once a filling is performed it will eventually have to be redone and the site serves as a vulnerable site for further decay. In general, early treatment is quicker and less expensive than treatment of extensive decay. Local anesthetics, nitrous oxide ("laughing gas"), or other prescription medications may be required in some cases to relieve pain during or following treatment or to relieve anxiety during treatment. A dental handpiece ("drill") is used to remove large portions of decayed material from a tooth. A spoon, a dental instrument used to carefully remove decay, is sometimes employed when the decay in dentin reaches near the pulp. Once the decay is removed, the missing tooth structure requires a dental restoration of some sort to return the tooth to function and aesthetic condition. Restorative materials include dental amalgam, composite resin, porcelain,

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and gold. Composite resin and porcelain can be made to match the color of a patient's natural teeth and are thus used more frequently when aesthetics are a concern. Composite restorations are not as strong as dental amalgam and gold; some dentists consider the latter as the only advisable restoration for posterior areas where chewing forces are great. When the decay is too extensive, there may not be enough tooth structure remaining to allow a restorative material to be placed within the tooth. Thus, a crown may be needed. This restoration appears similar to a cap and is fitted over the remainder of the natural crown of the tooth. Crowns are often made of gold, porcelain, or porcelain fused to metal.

A tooth with extensive caries eventually requiring extraction. In certain cases, endodontic therapy may be necessary for the restoration of a tooth. Endodontic therapy, also known as a "root canal", is recommended if the pulp in a tooth dies from infection by decaycausing bacteria or from trauma. During a root canal, the pulp of the tooth, including the nerve and vascular tissues, is removed along with decayed portions of the tooth. The canals are instrumented with endodontic files to clean and shape them, and they are then usually filled with a rubber-like material called gutta percha. The tooth is filled and a crown can be placed. Upon completion of a root canal, the tooth is now non-vital, as it is devoid of any living tissue. An extraction can also serve as treatment for dental caries. The removal of the decayed tooth is performed if the tooth is too far destroyed from the decay process to effectively restore the tooth. Extractions are sometimes considered if the tooth lacks an opposing tooth or will probably cause further problems in the future, as may be the case for wisdom teeth. Extractions may also be preferred by patients unable or unwilling to undergo the expense or difficulties in restoring the tooth.


Conclusion

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Dental caries is a multifactorial, infectious disease affecting a significant percentage of the population. It is more accurate to consider caries as caused, not by an infectious agent, but by a shift in oral microflora to caries-causing types in response to acidity resulting from metabolism of sugars. The development of caries is dependent on the interaction of four primary factors. These are a host (tooth surface), asubstrate (food), the presence of oral bacteria, and time. Caries will not develop if any of these four primary factors are not present. Understanding the etiology and pathways of progression of dental caries will enable the profession to strive toward early intervention and, hopefully, prevention.


Subject and Methods A cross-sectional study was conducted among 100 student in Tanbdy Preparatory School as rural sample and Elmassay Preparatory School as urban sample. This data were collected manually, qualitative data were expressed as number and percentage the Participants were subjected to :1. questionnaire Includes questions about ( Age , Sex ,Education Degree , Residance ,Income, Father Education , Mother Education,tooth cleaning, Past and family history of tooth decay among studied group, dietary habits and dental experience 2. Clinical examination:A. General: Height and weight

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B. local: oral examination about Tooth care


Results Table 1: Socio-demographic criteria of the studied group: Socio-demographic Criteria

Rural Urban Income Less than sufficient Sufficient More than sufficient Father Education Illiterate Read and write Secondary High Mother Education Illiterate Read and write Secondary High Father Occupation Worker Employee Professional Mother Occupation Housewife Worker Employee Professional Birth Order 1st 2nd 3rd

N= 100 13.21

No.

%

0 100

0 100

69 30 1

69 30 1

42

42

58

58

8 80 12

8 80 12

0 9 54 37

0 9 54 37

0 11 65 24

0 11 65 24

48 32 20

48 32 20

70 5 23 2

70 5 23 2

26 35 39

26 35 39

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Sex Male Female Education Degree 1st 2nd 3rd Residence

The Sudied Groups

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Items Age (mean)


Table 1 shows that:         

The sample size was 100 students form preparatory school. 100% of our sample was females. The majority of them (69%) in the first grade, 30% in second grade, and finally only 1% in third grade. 42% of them were living in rural area, and the other 58% were living in urban area. 80% of them their income was sufficient, 12% their income was more than sufficient, and only 8% their income was less than sufficient. With regard to their fathers’ education, 54% of them got secondary education, 37% got high education, and 9% could only read and write. According to their mothers’ education 56% of them got secondary education, 24% got high education, and only 11% could read and write. Concerning their father occupation 48% were workers, 32% were employees, and 20% were professionals. On the other hand the majority of their mothers (70%) were housewives, 23% were employees, and very small percentages were either workers or professionals. 39% of them were the third in their birth order, 35% were the second, and 26% were the first.

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Figure 1: show the Residence of the subjects in the study


Table 2: past and family history of tooth decay among the studied group: past and family history of tooth decay Items History of tooth pain Yes No History of visiting Dent. Yes No Number of visits no 1 2 3 more Brushing teeth Always sometimes no

The Sudied Groups

N=100

No.

%

87 13

87 13

78 22

78 22

22 18 28 10 22

22 18 28 10 22

16 76 8

16 76 8

60 40

60 40

0 100

0 100

Family History of tooth decay

yes no History of DM Yes No

Table 2 shows that:

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 87% of them had a history of tooth pain, and only 13 % of them didn’t have pain in their tooth.  The majority of them (78%) had a history of visiting dentist, and only 22% of them didn’t visit the doctor ever.  For those who visited the dentist 28% of them went to the doctor twice, 18% went to him only one time, 10% went to him three times, but 22% went to him more than 3 times.  The majority of them (76%) were sometimes brushing their teeth, 16% were always brushing their teeth, and only 8% did not brush their teeth at all.  60% of them had a family history of tooth decay, and 40% didn’t.  They all were fee of diabetes mellitus.


Table 3: Dietary history among the studied group:

Dietary History Items Dairy milk Products Daily Weekly Monthly never Animal Proteins Daily Weekly Monthly never Vegetable and fruits Daily Weekly Monthly never Biscuits and Chocolate Daily Weekly Monthly never Soft Drinks Daily Weekly Monthly never

The Sudied Groups No.

N=100 %

45 25 19 11

45 25 19 11

13 74 3 10

13 74 3 10

78 20 1 1

78 20 1 1

69 18 13 0

69 18 13 0

55 29 9 7

55 29 9 7

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Table 3 shows that:  45% ate milk product (cheese, milk and butter) daily, 25% ate them weekly, 19% ate them monthly, and 11 % never eat them at all.  The majority (74%) ate animal protein (meat, chicken and fish) weekly, 13% ate them daily, 3% ate them monthly, and 10% never eat them at all.  Concerning vegetable and fruits 78% ate them daily, 20% ate them weekly, and only small percent ate them either monthly or never.  On the other hand 69% ate biscuits and chocolate daily, 18% ate them weekly, and only 13 % ate them monthly.  However; 55% of them drank soft drinks daily, 29% drank them weekly, and small percent drank them either monthly or never.


Table 4: tooth examination among the studied group:

Examination Items

with tooth decay Yes

The Studied Groups N=100 Number 60 40

NO

Weight (mean)

51.06

Height (mean)

152.76

BMI (mean)

21.78

Figure 2: show subjects with and without tooth decay

Table 4 shows that:

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 Number of student having tooth decay was 60 students, and number of student don’t have tooth decay was 40 students.  The average of students’ weight and height was 51.6 kg and 152.76 cm respectively.  The average of the Body Mass Index was 21.78.


Table 5: comparison between subjects with and without tooth decay as regards Socio-demographic criteria: comparison between subjects with and without tooth decay as regards Socio-demographic criteria: Items

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Sex Male (0) Female (100) Education Degree 1st grade (69) 2nd grade (30) 3rd grade (1) Residence Rural (42) Urban (58) Income Less than sufficient (8) sufficient (80) More than sufficient (12) Father Education Illiterate (0) Read and write (9) Secondary (54) High (39) Mother Education Illiterate (0) Read and write (11) Secondary (65) High (24) Father Occupation Worker (48) Employee (32) Professional (20) Mother Occupation Housewife (70) Worker (5) Employee (23) Professional (2) Birth Order 1st (26) 2nd (35) 3rd (39)

The Studied Groups N=100 with tooth decay No. %

Normal No.

%

0 60

0 60

0 40

0 40

40 20 0

58 67 0

29 10 1

42 33 100

27 33

64 57

15 25

36 43

6 47 7

75 59 58

2 33 5

25 41 42

0 7 33 20

0 78 61 51

0 2 21 19

0 22 39 49

0 7 39 14

0 64 60 58

0 4 26 10

0 36 40 42

30 20 10

63 63 50

18 12 10

38 38 50

43 2 14 1

61 40 61 50

27 3 9 1

39 60 39 50

17 19 24

65 54 62

9 16 15

35 46 38


Table 5 shows that: The highest prevalence of tooth decay was found among:        

Second grade students: 67% of them had tooth decay and 33% did not have tooth decay. Students from rural area: 64% of students had tooth decay and 36% of students did not have tooth decay. Students whose income was less than sufficient: 75% of students had tooth decay and 25% of students did not have tooth decay. Students whose fathers can only read and write: 78% of them had tooth decay and 22% of them did not have tooth decay. Students whose mothers can only read and write: 64% of them had tooth decay and 36% of them did not have tooth decay. Students whose fathers worked as either workers or employees: 63% of them had tooth decay and 38% of them did not have tooth decay. Students whose mothers either worked as employees or do not work at all: 61% of them had tooth decay and 39% of them did not have tooth decay. The first and third birth order of students: 65% of them had tooth decay and 35% of them did not have tooth decay.

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Figure 3: show comparison between subjects with and without tooth decay as regards rural and urban area


Table 6: comparison between subjects with and without tooth decay as regards past and family history of tooth decay: comparison between subjects with and without tooth decay as regards past and family history Items

The Sudied Groups N= 100 with tooth decay No. %

History of tooth pain yes (60) no (40) History of visiting Dent. yes (78) no (22) Number of visits no (22) 1 (18) 2 (28) 3 (10) more (22) Brushing teeth Always (16) sometimes (76) no (8) Family History yes (60) no (40) History of DM Yes (0) No (100)

Normal No.

%

55 32

91 80

5 8

9 20

51 9

65 41

27 13

35 59

9 11 18 6 16

41 61 64 60 73

13 7 10 4 6

59 39 36 40 27

5 48 7

31 63 88

11 28 1

69 37 13

44 16

73 40

16 24

27 60

0 60

0 60

0 40

0 40

Table 6 shows that: The highest prevalence of tooth decay was found among:   

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 

Students who had history of tooth pain: 91% of them had tooth decay and only 9% of them did not have tooth decay. Students who had history of visiting the dentist: 65% of them had tooth decay and 35% of them did not have tooth decay. Students visited the dentist more than three times: 60% of them had tooth decay and 40% did not have tooth decay. Students who never brush their teeth: 88% of them had tooth decay and 13% did not have tooth decay. Students who had family history of tooth decay: 73% of them had tooth decay and only 27% of them did not have tooth decay.


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Figure 4 : show comparison between subjects with and without tooth decay as regards brushing teeth


Table 7: comparison between subjects with and without tooth decay as regards dietary history: dietary history Items

The Sudied Groups N= 100 with tooth decay No. %

Dairy Products Daily (45) Weekly (25) Monthly (19) Never (11) Animal Proteins Daily (13) Weekly (74) Monthly (3) Never (10) Vegetable and fruits Daily (78) Weekly (20) Monthly (1) Never (1) Biscuits and Chocolate Daily (69) Weekly (18) Monthly (13) Never (0) Soft Drinks Daily (55) Weekly (29) Monthly (9) Never (7)

Normal No.

%

24 16 15 6

53 64 79 55

21 9 4 5

47 36 21 45

9 42 2 7

69 57 67 70

4 32 1 3

31 43 33 30

43 16 1 0

55 80 100 0

35 4 0 1

45 20 0 100

46 9 5 0

67 50 38 0

23 9 8 0

33 50 62 0

36 16 3 2

65 55 33 29

19 13 6 5

35 45 67 71

Table 7 shows that: The highest prevalence of tooth decay was found among: 

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  

Students who ate milk product monthly: 79% of them had tooth decay and 21% of them did not have tooth decay. Students who never eat animal protein: 70% of them had tooth decay and 30% of them did not have tooth decay. Students who ate vegetable and fruits weekly: 80% of them had tooth decay and 20% of them did not have tooth decay. Students who ate biscuits and chocolate daily: 67% of them had tooth decay and 33% of them did not have tooth decay.




Students who drank soft drinks daily: 65% of them had tooth decay and 35% of them did not have tooth decay.

Figure 5 : show comparison between subjects with and without tooth decay as regards Biscuits and Chocolate intake

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Figure 6: show comparison between subjects with and without tooth decay as regards soft drink intake


Table 8: comparison between subjects with and without tooth decay as regards anthropometric measurement: Items

The Studied Groups N=100 with tooth decay

Normal

Weight(mean)

50.5

51.9

Height(mean)

152.12

153.73

BMI (mean)

21.74

21.83

Table 8 shows that:   

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Student with average weight 50.5 Kg had tooth decay and student with average weight 51.9 Kg did not have tooth decay. Student with average height 152.12 cm had tooth decay and student with average height 153.73 cm did not have tooth decay. Student with average body mass index 21.74 had tooth decay and student with average body mass index 21.83 did not have tooth decay. There was no real significance difference of weight and height on tooth decay.


60% of females in this sample have tooth decay and 40% of them free of tooth decay. The highest prevalence of tooth decay was among second grade students. In rural area 64% of students had tooth decay and 36% of students did not have tooth decay. In urban area 57% of students had tooth decay and 43% of students did not have tooth decay. The highest prevalence of tooth decay was among students from rural area. Concerning the students whose income was less than sufficient, 75% of students had tooth decay and 25% of students did not have tooth decay. On the other hand, students whose income was sufficient, 59% of students had tooth decay and 41% of students did not have tooth decay. However, students whose income was more than sufficient, 58% of them had tooth decay and 42% of them did not have tooth decay.

The highest prevalence of tooth decay was among students whose income was less than sufficient. Concerning students whose fathers can only read and write 78% of them had tooth decay and 22% of them did not have tooth decay. However, students whose fathers’ education was high, 51% of them had tooth decay and 49% of them did not have tooth decay. The highest prevalence of tooth decay was among students whose fathers can only read and write. Concerning students whose mothers can only read and write 64% of them had tooth decay and 36% of them did not have tooth decay. However, students whose mothers’ education was high, 58% of them had tooth decay and 42% of them did not have tooth decay. The highest prevalence of tooth decay was among students whose mothers can only read and write. Concerning students whose fathers worked as worker 63% of them had tooth decay and 38% of them did not have tooth decay. On the other hand, students whose fathers worked as

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The current study reveals that there is many factors affect dental carries in school students, such as sociodemographic criteria of the students; present, past or family history of tooth decay; dietary history; anthropometric measures.

| 30

Discussion


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| 31

employee, 63% of them had tooth decay and 38% of them did not have tooth decay. However, students whose fathers worked as professional, 50% of them had tooth decay and 50% of them did not have tooth decay. The highest prevalence of tooth decay was among students whose fathers worked as either workers or employees. Concerning students whose mothers did not work (Housewife), 61% of them had tooth decay and 39% of them did not have tooth decay. On the other hand, students whose mothers worked as worker, 40% of them had tooth decay and 60% of them did not have tooth decay. The highest prevalence of tooth decay was among students whose mothers either worked as employees or did not work at all. There was no a real difference between the first and third birth order of students having tooth decay. Concerning students who had history of tooth pain, 91% of them had tooth decay and only 9% of them did not have tooth decay. On the other hand, students who did not have history of tooth pain, 80% of them had tooth decay and 20% did not have tooth decay. The highest prevalence of tooth decay was among students who had history of tooth pain.

Concerning students who had history of visiting the dentist, 65% of them had tooth decay and 35% of them did not have tooth decay. On the other hand, students who did not have history of visiting the dentist, 41% of them had tooth decay and 59% did not have tooth decay. The highest prevalence of tooth decay was among students who had history of visiting the dentist. Students who visited the dentist three times, 60% of them had tooth decay and 40% did not have tooth decay. Students who visited the dentist more than three times, 73% of them had tooth decay and 27% did not have tooth decay. The highest prevalence of tooth decay was among students visited the dentist more than three times. Concerning students who always brush their teeth, 31% of them had tooth decay and 69% of them did not have tooth decay. However, students who never brush their teeth, 88% of them had tooth decay and 13% did not have tooth decay. The highest prevalence of tooth decay was among students who never brush their teeth. The highest prevalence of tooth decay was among students who had family history of tooth decay. There is no history of diabetes mellitus, so we cannot measure


On the other hand, students who ate biscuits and chocolate monthly, 38% of them had tooth decay and 62% of them did not have tooth decay. The highest prevalence of tooth decay was among students who ate biscuits and chocolate daily. Concerning students who drank soft drinks daily, 65% of them had tooth decay and 35% of them did not have tooth decay. students who never drink soft drinks, 29% of them had tooth decay and 71% of them did not have tooth decay The highest prevalence of tooth decay was among students who drank soft drinks daily. Student with average weight 50.5 Kg had tooth decay and student with average weight 51.9 Kg did not have tooth decay. Student with average height 152.12 cm had tooth decay and student with average height 153.73 cm did not have tooth decay. Student with average body mass index 21.74 had tooth decay and student with average body mass index 21.83 did not have tooth decay. There was no real significance difference of weight and height on tooth decay.

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the incidence of tooth decay in diabetic students. Concerning students who ate milk product daily, 53% of them had tooth decay and 47% of them did not have tooth decay. On the other hand, students who ate milk product monthly, 79% of them had tooth decay and 21% of them did not have tooth decay. The highest prevalence of tooth decay was among students who ate milk product monthly. Students who ate animal protein weekly, 57% of them had tooth decay and 43% of them did not have tooth decay. Students who never eat animal protein, 70% of them had tooth decay and 30% of them did not have tooth decay The highest prevalence of tooth decay is among students who never eat animal protein. Concerning students who ate vegetables and fruits daily, 55% of them had tooth decay and 45% of them did not have tooth decay. However, students who ate vegetables and fruits weekly, 80% of them had tooth decay and 20% of them did not have tooth decay. The highest prevalence of tooth decay was among students who ate vegetable and fruits weekly. Concerning students who ate biscuits and chocolate daily, 67% of them had tooth decay and 33% of them did not have tooth decay.


This study is correlated with other studies in different counties: Dental caries and oral health practice among 12 year old school children from low socio-economic status background in Zimbabwe Aim:

It States that Dental caries is one of the most prevalent chronic diseases affecting children in Sub-Saharan Africa. Previous studies show a higher prevalence of dental caries in children from low socioeconomic status backgrounds. The purpose of this study was to determine the prevalence of dental caries among 12 year old children in urban and rural areas of Zimbabwe and establish preliminary baseline data. The Results were: Our results showed a high prevalence of dental caries in both urban (59.5%) and rural (40.8%) children. The mean DMFT in urban and rural areas was 1.29 and 0.66, respectively. Furthermore, our data showed a general lack of knowledge on oral health issues by the participants.

The prevalence of dental caries among 12 to 15-year-old school children in Nigeria: report of a local survey and campaign. Aim: It aims to assess the prevalence of dental caries among school children in Egor local government area (district) and establish baseline data.

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RESULTS: Sixty-seven percent (n = 238) of the school children were caries-free. Mean DMFT score was 0.65 (sd = 1.14). Decayed teeth

accounted for the largest component (98.6%). No fillings were recorded. Prevalence (mean DMFT) was higher in females (0.70) than males (0.59), urban (0.72) more than rural (0.53); private schools (0.75) more than public schools (0.55). DMFT scores at age 12, 13, 14 and 15 were 0.51, 0.63, 0.78 and 0.66 respectively; 81.4% of the school children had never visited a dental clinic, 95.8% claimed to use a toothbrush and 87.5% regularly consumed snacks.

Conclusion Our data shows a high prevalence of dental caries among school children in both urban and rural areas. The study reported 60% of school children suffered oral pain and decayed teeth. The brushing habit was reportedly low with only 16% of the children always brushing their teeth. This data may be of importance in the evaluation of the past and planning of future oral health prevention and treatment programs targeting young children in schools. A comprehensive community-focused oral health care intervention that includes oral health education in schools and homes is recommended to increase general oral health awareness.


Obstacles

among student, some of them

There were some difficulties during the

redistribute other questioners to

project we had done. They weren’t great

other student to reach the

difficulties, but we had to summarize

required number of samples.

were leaving without handing the questioners,

so

we

had

to

7. In subject group there wasn’t

them in: 1. Since this was a cross-sectional therefore

it

cannot

establish temporal associations

grade, it was only one, so it may be not really representive.

regard

future

8. We didn’t bring height calculator

studies

are

with us to measure student’s

suggested to establish causal

height, so we had to mark the

associations for risk factors with

wall with a ruler.

in

this

longitudinal

9. There

dental caries. 2. True results might have been hampered

due

to

incorrect

reporting (reporting bias) by the

samples

wasn’t

enough

from

free

(signal

2)

Toothpaste for all student. 10. Some questions in the questioner weren’t clear to some students.

students. 3. It was our first time to do a

11. The project overlaps with our exams.

statistical analysis. 4. There wasn’t diversity in choosing

12. Dental carries isn’t a popular

the samples, and they were

subject in our faculty, so we had

concentrated in certain group,

an external help from students in

they all were females.

Faculty of Dentistry to recognize

5. In the day we went to collect the required data, the school had a fun day and it was difficult for us

the facts and previous researches in such a subject. 13. During

entry

of

data

some

to gather all student in one place.

questioners weren’t complete, so

6. There wasn’t a specific place to

we had to exclude uncompleted

fill the questioners, so after distribution

of

questioners

data.

| 34

and

Page

study;

enough samples from the third


Recommendations  Brush your teeth at least twice a day with a fluoride-containing toothpaste. Preferably, brush after each meal and especially before going to bed.  Brush your teeth every morning. Be sure you brush thoroughly—brush both up and down and side to side. Don't forget to brush back behind your molars; the back of the mouth is often forgotten and is one of the most susceptible to decay.

surfaces of your back teeth (molars) to protect them from decay.

Drink fluoridated water. At least a pint of fluoridated water each day is needed to protect children from tooth decay.

Eat a diet high in calcium .Calcium helps strengthen tooth surfaces.

Visit your dentist regularly for professional cleanings and oral exam. At least twice a year. They will clean your teeth and check for cavities.

Avoid eating high sugar and/or high acid foods (cookies, candy, and soda) between meals, cut down on snacks between meals: This will help prevent plaque from making acid .It will also reduce the number of times your teeth are exposed to acids.. Be careful with diet soda, it may not have sugar but it certainly has a lot of acid which is bad.

Drink plenty of water, especially if you take certain medicines.Some medicines can decrease the amount of saliva your body makes. This may put you at greater risk for tooth decay.

If you don't have time to brush, at least gargle clean, fresh water.

 Clean between your teeth daily with dental floss or interdental cleaners, such as the Oral-B Interdental Brush.  Make sure you use a soft bristled toothbrush. If you don't, your gums could bleed very easily, and it could irritate your mouth.

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 Eat nutritious and balanced meals and limit snacks. Avoid carbohydrates such as candy, pretzels and chips, which can remain on the tooth surface. If sticky foods are eaten, brush your teeth soon afterwards. 

Check with your dentist about use of supplemental fluoride, which strengthens your teeth.

Ask your dentist about dental sealants (a plastic protective coating) applied to the chewing


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Brush and floss before bed. Look at it this way: Your mouth is going to be closed for the 8 straight hours, it's like an incubator for the bacteria making them grow like crazy.

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


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References 1. National Institute of Dental and Craniofacial Research, National Institutes of Health. Dental Caries (Tooth Decay) in Adults (Age 20 to 64). National Institute of Dental and Craniofacial Research. Last updated March 20, 2010. Accessed June 15, 2010. 2. Gerabek WE. The tooth-worm: historical aspects of a popular medical belief. Clin Oral Investig. 1999 Mar;3(1):1-6. 3. Newbrun E. Sugar and dental caries: a review of human studies. Science. 1982 Jul 30;217(4558):418-23. 4. Christen AG. Sumter Smith Arnim, DDS, PhD (1904-1990): a pioneer in preventive dentistry. J Dent Res. 1995 Oct;74(10):1630-5. 5. Ismail AI, Hasson H, Sohn W. Dental caries in the second millennium. J Dent Educ. 2001 Oct;65(10):953-9. 6. Ripa LW. A half-century of community water fluoridation in the United States: review and commentary. J Public Health Dent. 1993 Winter;53(1):17-44. 7. American Dental Association. Fluoridation Facts 2005. PDF file. 8. Filoche S, Wong L, Sissons CH. Oral biofilms: emerging concepts in microbial ecology. J Dent Res. 2010 Jan;89(1):8-18. 9. Marsh PD, Martin MV. Oral Microbiology. 5th ed. 2009; Edinburgh: Churchill Livingstone Elsevier. 10. Ochiai K, Kurita-Ochiai T, Kamino Y, Ikeda T. Effect of co-aggregation on the pathogenicity of oral bacteria. J Med Microbiol. 1993 Sep;39(3):18390. 11. Beighton D. The complex oral microflora of high-risk individuals and groups and its role in the caries process. Community Dent Oral Epidemiol. 2005 Aug;33(4):248-55.

12. Burne RA. Oral streptococci... products of their environment. J Dent Res. 1998 Mar;77(3):445-52. 13. Marsh PD. Microbial ecology of dental plaque and its significance in health and disease. Adv Dent Res. 1994 Jul;8(2):263-71. 14. Keijser BJ, Zaura E, Huse SM, et al. Pyrosequencing analysis of the oral microflora of healthy adults. J Dent Res. 2008 Nov;87(11):1016-20. 15. Touger-Decker R, van Loveren C. Sugars and dental caries. Am J Clin Nutr. 2003 Oct;78(4):881S-892S. 16. Marsh PD. Are dental diseases examples of ecological catastrophes? Microbiology. 2003 Feb;149(Pt 2):279-94. 17. Hicks J, Garcia-Godoy F, Flaitz C. Biological factors in dental caries: role of saliva and dental plaque in the dynamic process of demineralization and remineralization (part 1). J Clin Pediatr Dent. 2003 Fall;28(1):47-52.


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