Epidemiology Of Dental Epidemiology Of Dental CariesCaries

Dental CariesDental Caries

Dental caries is an ancient disease; Dental caries is an ancient disease; paleontological evidence shows that paleontological evidence shows that it has troubled humans from the time it has troubled humans from the time that agriculture replaced hunting as that agriculture replaced hunting as the principal source of food.the principal source of food.

Low Caries incidence Low Caries incidence existed in Ancient Manexisted in Ancient Man

•Examination of ancient skulls

shows that:

Low caries incidence in the Low caries incidence in the ancient man is due to ancient man is due to dietdiet which which was :was :

Comparatively Comparatively low low inin carbohydrates. carbohydrates.

Natural Natural (unrefined) diet.(unrefined) diet.

Coarse Coarse & not & not fully prepared or fully prepared or cooked.cooked.

Pattern Of Ancient Dental Pattern Of Ancient Dental CariesCaries

• The pattern of ancient caries as The pattern of ancient caries as revealed by lesions in ancient skulls revealed by lesions in ancient skulls was mostly cervical or root caries and was mostly cervical or root caries and coronal caries was relatively coronal caries was relatively uncommon.uncommon.

• Coronal caries seemed to start in the Coronal caries seemed to start in the occlusal fissures but developed no occlusal fissures but developed no further because the rate of attrition further because the rate of attrition was faster than the rate of progression. was faster than the rate of progression.

Pattern Of Ancient Dental CariesPattern Of Ancient Dental Cariescont.cont.

The ancient pattern of dental caries The ancient pattern of dental caries was replaced in the 17was replaced in the 17thth century by a century by a new pattern where a lesion begins in new pattern where a lesion begins in fissured surfaces and develops later fissured surfaces and develops later on proximal surfaces.on proximal surfaces.

• This pattern took place in the This pattern took place in the industrialized nations as a result of industrialized nations as a result of the increased use of sucrose as sugars the increased use of sucrose as sugars became more available.became more available.

Current globalCurrent global distributiondistribution

During most of the 20During most of the 20thth

century, dental cariescentury, dental cariespattern was :pattern was :I.I. HighHigh prevalenceprevalence inin

developed countriesdeveloped countries & & higher socioeconomic higher socioeconomic group.group.

II.II. LowLow prevalence in prevalence in developing countries with developing countries with less economic less economic development.development.

Caries was referred to as Caries was referred to as ““a disease of civilization.”a disease of civilization.”

Global DistributionGlobal Distribution

The most obvious reason for this historical The most obvious reason for this historical pattern is diet; the high level of pattern is diet; the high level of consumption of refined carbohydrates in consumption of refined carbohydrates in developed countries in contrast to diets low developed countries in contrast to diets low in fermentable carbohydrates in poorer in fermentable carbohydrates in poorer societies where hunting and farming are the societies where hunting and farming are the main source of food. main source of food.

HighHigh level of consumption of level of consumption of refined carbohydrates in refined carbohydrates in developeddeveloped countries led countries led to increase in cariogenic bacteria.to increase in cariogenic bacteria.

Diet Diet lowlow in fermentable in fermentable carbohydrates in carbohydrates in developingdeveloping countries surviving on farming countries surviving on farming &hunting lower level of &hunting lower level of cariogenic bacteria.cariogenic bacteria.

Explanation of this pattern is :Explanation of this pattern is :diet

By the late 20By the late 20thth century century, , cariescaries patternpattern was changing in two ways:was changing in two ways:

1- 1- Sharp rising Sharp rising in caries in caries prevalenceprevalence and and severityseverity in most in most developingdeveloping countries especially countries especially urban areas.urban areas.

2- 2- Marked reduction Marked reduction among among children & young adults in children & young adults in developeddeveloped countries. countries.

In both In both developeddeveloped and and developingdeveloping countries , there countries , there are distinct are distinct variationsvariations in in caries experience from one caries experience from one country to another and from country to another and from region to another withinregion to another within

The same Country.

The decline of caries is attributed to:The decline of caries is attributed to:Use of fluoridated tooth paste.Use of fluoridated tooth paste.Fluoridation of water supplies.Fluoridation of water supplies.The use of The use of fissure sealantsfissure sealants.. Implementation of Implementation of preventive programspreventive programs better access to health care better access to health care better living conditions.better living conditions.Change of Change of sugar consumptionsugar consumption, although , although

the change is not substantial.the change is not substantial.

Global DistributionGlobal Distributioncont.cont.

upward trend of caries in many upward trend of caries in many developing countries is related to:developing countries is related to:

The absence of widespread caries The absence of widespread caries preventive strategy.preventive strategy.

Increasing consumption of sugar Increasing consumption of sugar containing products.containing products.

The distribution pattern of The distribution pattern of dental caries closely follows dental caries closely follows that of plaque. Thus, the that of plaque. Thus, the sites in the mouth which sites in the mouth which are most prone to caries are are most prone to caries are those where plaque those where plaque accumulates.accumulates.

Variation of caries within the mouth:Variation of caries within the mouth:

These sites are:These sites are:1.1. The The fissuresfissures in in

the occlusal the occlusal surfaces of molars.surfaces of molars.

2.2. The The proximalproximal areas.areas.

3.3. The The marginal area marginal area between the tooth between the tooth and the gingiva.and the gingiva.

I- Types of dental I- Types of dental cariescaries

1)1)Pit & fissure caries:Pit & fissure caries:

It is the first to It is the first to appear in the mouth.appear in the mouth.

Pits &fissure Pits &fissure surfaces constitute surfaces constitute the most susceptible the most susceptible surfaces in the surfaces in the mouth.mouth.

2) Proximal caries:2) Proximal caries:

It is the next to It is the next to appear in the appear in the mouth.mouth.

It is related to It is related to plaque plaque accumulation in the accumulation in the non-self cleansing non-self cleansing areas (beneath the areas (beneath the contact points).contact points).

3) Cervical caries3) Cervical caries

Is the third type of dental Is the third type of dental caries that occurs caries that occurs uniformly throughout life.uniformly throughout life.

It is related to progressive It is related to progressive changes in the free changes in the free gingival margin,gingival margin, poor oral poor oral hygiene & decreased hygiene & decreased salivary flow (xerostomia)salivary flow (xerostomia)

,.,.

4) Root caries:4) Root caries:Occurs usually in Occurs usually in

old age (60 y<).old age (60 y<).Root surfaces Root surfaces

become exposed become exposed by gingival by gingival recession in recession in advancing age.advancing age.

These exposed These exposed areas provide areas provide perfect areas for perfect areas for plaque plaque accumulation.accumulation.

II-Susceptibility of different II-Susceptibility of different teethteeth

Dental caries in the Dental caries in the human mouth is human mouth is usually distributed usually distributed in a bilateral in a bilateral symmetry.symmetry.

Susceptibility Of Different Susceptibility Of Different TeethTeeth

According to the pioneering According to the pioneering Hagerstown studies (1937), Hagerstown studies (1937), the rank order of the rank order of susceptibility of teeth to susceptibility of teeth to caries was listed as follows:caries was listed as follows:

Mandibular 1st & 2nd molars

Max. 1st & 2nd molars

Mand. 2nd,max. 1st & 2nd premolarsmax. central & lateral incisors.

Max. canines & mand. 1st premolars

Mand. Central& lateral Incisors & canines.

1

2

3

4

5

Dental CariesDental Caries

It is the disease of calcified tissues.It is the disease of calcified tissues. It is a maltifactorial disease in which It is a maltifactorial disease in which

the following risk factors play role in the following risk factors play role in its causation process:its causation process:

1.1. Agent: Microorganisms Agent: Microorganisms

2.2. Host: Personal and tooth risk factors.Host: Personal and tooth risk factors.

3.3. Environment: Dietary, and oral Environment: Dietary, and oral hygiene related risk factors.hygiene related risk factors.

Host

1- Age.

2- Gender.

3- Race.

4- Genetic &familial.

5- Role of saliva. 6- Nutrition

7-Systemic diseases and drugs.

Agent

1-Streptococcus mutans.

2- Lactobacilli.

3- Actinomyces.

Environmental

1-Flouride.

2-diet.

3-Social factors.

Microbial agent

Dental caries is a Dental caries is a bacterial bacterial diseasedisease..

Regardless of any other Regardless of any other factor, caries factor, caries does notdoes not occur occur in the absence of bacteria.in the absence of bacteria.

Agent Factors of Dental CariesAgent Factors of Dental CariesMicroorganismsMicroorganisms

Mainly Mainly Streptococcus mutansStreptococcus mutans are are responsible for initial development of dental responsible for initial development of dental caries with contribution of other species caries with contribution of other species such as:such as:

Lactobacillus acidophilus Lactobacillus acidophilus Lactobacillus caseiLactobacillus casei Streptococcus salivariusStreptococcus salivarius Strpetococcus milleriStrpetococcus milleri Streptococcus sanguisStreptococcus sanguis Actinomycis (root caries)Actinomycis (root caries)

Strept. Mutans has the ability to:Strept. Mutans has the ability to:

1- Implantation on tooth surface 1- Implantation on tooth surface by by synthesis of adhesive extra- synthesis of adhesive extra- cellular polysaccharidescellular polysaccharides (glucans) (glucans) from sucrose which they use to from sucrose which they use to stick and colonize on tooth stick and colonize on tooth surface.surface.

2-2- Store intra-cellular Store intra-cellular polysaccharidespolysaccharides which act which act as a transient reserves of as a transient reserves of fermentable carbohydrates.fermentable carbohydrates.

3-3- Fermentation of dietary Fermentation of dietary carbohydrates carbohydrates as an energy as an energy source for its metabolic source for its metabolic activity and produces lactic activity and produces lactic acid.acid.

Streptococcus mutans

LactobacilliLactobacilli could be considered as could be considered as secondary contributors secondary contributors for the for the process.process.

They generally constitute They generally constitute less than less than 1% 1% of the plaque microbiota.of the plaque microbiota.

Their number is often increased Their number is often increased in caries active plaque because in caries active plaque because they they grow well under acid grow well under acid conditioncondition..

Lactobacilli Lactobacilli are more a are more a consequence than a cause of consequence than a cause of caries initiation.caries initiation.

The host Risk Factors

1- Age. 1- Age. 2- Gender. 2- Gender. 3- Race. 3- Race. 4- Genetic & familial.4- Genetic & familial. 5- Role of saliva. 5- Role of saliva.

6- Nutrition6- Nutrition 7-Systemic diseases and drugs. 7-Systemic diseases and drugs.

Age Age

Caries Caries waswas considered a considered a childhood disease childhood disease becausebecause all all susceptible tooth susceptible tooth surfaces become surfaces become carious during early carious during early child years and few child years and few carious lesions are carious lesions are affected during affected during adulthood.adulthood.

Age Age

• In communities with In communities with lower attack rate, lower attack rate, young people reach young people reach adulthood with most adulthood with most surfaces caries free surfaces caries free and caries attack and caries attack spread out more spread out more throughout life.throughout life.

Age Age

Caries Caries increasesincreases progressively progressively by age, and the by age, and the increase is increase is more slowly during adult yearsmore slowly during adult years

This is due toThis is due to:: Most of the susceptible Most of the susceptible

surfaces are likely to have surfaces are likely to have been attacked by that time.been attacked by that time.

The build up fluoride in The build up fluoride in outer layers of enamel over outer layers of enamel over time.time.

After After age of 60age of 60 years, caries increases years, caries increases again because of again because of root root cariescaries..

GenderGender

It is observed It is observed that caries that caries prevalence is prevalence is higherhigher in in femalesfemales than in than in males of the males of the same age.same age.

Females generally demonstrate Females generally demonstrate higherhigher

DMF scores than males probably DMF scores than males probably due to :due to :

• The earlier tooth eruption in females; The earlier tooth eruption in females; their teeth are at risk for a longer time.their teeth are at risk for a longer time.

• Females visit the dentist more Females visit the dentist more frequently (treatment factor).frequently (treatment factor).

The impact of these determinant, The impact of these determinant, however has not been well quantified.however has not been well quantified.

RaceRaceEarly studiesEarly studies, observed that , observed that

some races as those in Africa & some races as those in Africa & India, had India, had highhigh degree of caries degree of caries resistanceresistance than than ““EuropeansEuropeans””..

RecentlyRecently, the concept of racial , the concept of racial differences have been differences have been faded, faded, andand the evidence reveals that the evidence reveals that the global differences the global differences are the are the result of environment.result of environment. ..

RaceRaceThis was supported by the fact that This was supported by the fact that

these racial groups, once thought to these racial groups, once thought to be resistant to caries (Africans and be resistant to caries (Africans and Indians), quickly developed the Indians), quickly developed the disease when they moved to areas disease when they moved to areas with different with different cultural and dietary cultural and dietary patternspatterns. .

The variation in caries prevalence is The variation in caries prevalence is the result of the result of environmental environmental ratherrather than they are of racial attributes.than they are of racial attributes.

Familial & genetic patternFamilial & genetic pattern

Dental caries has Dental caries has long ago shown to long ago shown to bbe grouped e grouped according to according to families.families.

Members of the Members of the same household same household were found to be were found to be alike in their caries alike in their caries pattern than pattern than between unrelated between unrelated groups of groups of individuals. individuals.

Such familial tendency may be due to:Such familial tendency may be due to:

1-1- Interfamilial Interfamilial bacterialbacterial transmission, especially from transmission, especially from mother to baby.mother to baby.

2-2- similarity in similarity in dietarydietary & & oral oral hygiene hygiene habits. OR,habits. OR,

3-3- Genetic factorGenetic factor: as inheritance of : as inheritance of tooth structure (deep narrow pits & tooth structure (deep narrow pits & fissures) or special arch form fissures) or special arch form (irregularities & crowding).(irregularities & crowding).

Socioeconomic statusSocioeconomic status

• It is a measure of the individual’ It is a measure of the individual’ background; background; education, income, education, income, occupation, and attitudes and occupation, and attitudes and values.values.

• It is It is inversely related inversely related to the to the status of many disease.status of many disease.

• It is a It is a powerful determinant powerful determinant of of caries status in any community. caries status in any community.

Socioeconomic statusSocioeconomic status

Earlier studies found that Earlier studies found that higher SES higher SES groups had groups had higher DMFhigher DMF scores than scores than those in the lower SES groups.those in the lower SES groups.

Details of DMF scores showed that Details of DMF scores showed that lower SES lower SES groups hadgroups had higherhigher values values forfor DD andand MM, , lowerlower for for FF..

Whereas, the increased number of Whereas, the increased number of filled teeth (F) raised the DMF index filled teeth (F) raised the DMF index among the high SES groups among the high SES groups ““treatment factortreatment factor””..

The The differencedifference between between social groups is due to social groups is due to increased number of filled increased number of filled teeth (F)teeth (F) that raised the that raised the whole DMF index among whole DMF index among high SES groups high SES groups ““treatment treatment factorfactor””..

Socioeconomic Status Socioeconomic Status (SES):(SES):

With the reported caries decline, With the reported caries decline, the DMF values of the DMF values of the higher SES the higher SES groups groups became considerably became considerably belowbelow those in the lower SES those in the lower SES group.group.

The The inverseinverse relationship between relationship between caries status and SES have been caries status and SES have been reported from Britain and reported from Britain and elsewhere in Europe.elsewhere in Europe.

The same was reported in Africa.The same was reported in Africa.

NutritionNutrition Nutrition refers to the Nutrition refers to the

absorption of nutrients and their absorption of nutrients and their utilization by the body cells for utilization by the body cells for structural and functional structural and functional efficiency.efficiency.

NutritionNutrition can act only through can act only through the the systemic route systemic route through through influencing the host during tooth influencing the host during tooth development. development.

Nutrition and Dental CariesNutrition and Dental Caries There is some evidence that There is some evidence that chronic chronic

malnourishmentmalnourishment during development during development periods in a poor society may periods in a poor society may predispose to caries.predispose to caries.

No relation between No relation between nutritional nutritional adequacy adequacy and and DMFDMF scores could be find. scores could be find.

Vitamin D deficiency Vitamin D deficiency may cause enamel may cause enamel hypoplasia.hypoplasia.

Selenium: Is a Selenium: Is a cariogenic trace element cariogenic trace element when consumed during tooth when consumed during tooth developmental period .developmental period .

Prior to modern preventive Prior to modern preventive methods :methods :

Caries prevalence Caries prevalence was low in countries was low in countries with with low living standardslow living standards, where , where generalized generalized malnutritionmalnutrition was the norm. was the norm.

Current epidemiological evidence Current epidemiological evidence favors the conclusion that favors the conclusion that nutritional nutritional statusstatus does does not directly influence not directly influence the the prevalence of dental caries (except for prevalence of dental caries (except for fluoride).fluoride).

Role of Saliva Role of Saliva DilutingDiluting effect on fermented food effect on fermented food

residues.residues.BufferingBuffering capacity to neutralize capacity to neutralize

acid end products resulting from acid end products resulting from such fermentation.such fermentation.

Provides ions for Provides ions for remineralization remineralization of early carious lesions.of early carious lesions.

Provides Provides antibacterialantibacterial, , antifungalantifungal and and antiviralantiviral agents. agents.

Systemic diseases and drugs Systemic diseases and drugs causing diminished salivationcausing diminished salivation

(xerostomia)(xerostomia) . . Oral SymptomsOral Symptoms Dry mouth (xerostomia)Dry mouth (xerostomia) ThirstThirst Difficulty in swallowing (dysphagia)Difficulty in swallowing (dysphagia) Difficulty in speaking (dysphonia)Difficulty in speaking (dysphonia) Difficulty in eatingDifficulty in eating dry fooddry food Need do drink water frequently at mealsNeed do drink water frequently at meals Difficulty in wearing Difficulty in wearing denturesdentures Frequent pain of the throat,Frequent pain of the throat, simulating tonsillitis. simulating tonsillitis.

Systemic diseases and drugs Systemic diseases and drugs causing diminished salivationcausing diminished salivation

(xerostomia)(xerostomia) . .

Causes of xerostomiaCauses of xerostomia

1. 1. Drugs/medications:Drugs/medications:AnalgesicsAnalgesicsAntiarthriticAntiarthriticAntispasmodic (gastrointestinal)Antispasmodic (gastrointestinal)AntidepressantAntidepressantAntidiarrhealAntidiarrhealAntihistaminicAntihistaminicAntihypertensiveAntihypertensive

2. Irradiation particularly of the 2. Irradiation particularly of the head and neck area.head and neck area.

3. Systemic diseases :3. Systemic diseases : Rheumatoid conditionsRheumatoid conditions Psychogenic disorders Psychogenic disorders

(depression)(depression) Anorexia nervosa, malnutritionAnorexia nervosa, malnutrition MenopauseMenopause Salivary gland stonesSalivary gland stones Aging (a contributory factor)Aging (a contributory factor) Decreased masticatory activity Decreased masticatory activity

(liquid diet, soft food)(liquid diet, soft food)

Environmental Risk FactorsEnvironmental Risk Factorsof Dental Cariesof Dental Caries

Diet :Diet :• Diet refers to the total intake of Diet refers to the total intake of

substances that provide nourishment substances that provide nourishment and energy.and energy.

DietDietDiet refers to the total intake Diet refers to the total intake

of substances that provide of substances that provide nourishment and energy.nourishment and energy.

Balanced DietBalanced Diet

It is one which contains all nutrients It is one which contains all nutrients in such in such quantitiesquantities and and proportionsproportions so so as to fulfill the need of calories.as to fulfill the need of calories.

DietDietIntake of Intake of refined carbohydrates refined carbohydrates

especially sucrose (especially sucrose (sugarsugar) is ) is considered a considered a strong etiologic strong etiologic factor factor in the causation of dental caries.in the causation of dental caries.

Diet and Dental CariesDiet and Dental CariesCariostatic effectCariostatic effect

Carbohydrate: Sucrose is the most Carbohydrate: Sucrose is the most cariogenic carbohydrate.cariogenic carbohydrate.

Protein: High protein diet is cariostatic.Protein: High protein diet is cariostatic.Fat: Fats are cariostatic.Fat: Fats are cariostatic.Phosphates: Phosphates are cariostatic.Phosphates: Phosphates are cariostatic.Fluorides: Increase the resistance of Fluorides: Increase the resistance of

enamel to acid dissolution.enamel to acid dissolution.Vitamin B6 (Pyridoxine): prevent dental Vitamin B6 (Pyridoxine): prevent dental

caries by altering the microbial flora.caries by altering the microbial flora.

Diet and Dental CariesDiet and Dental Caries Cariogenicity of the diet :Cariogenicity of the diet : Sugars and Sugars and

fermentable carbohydrates are a major fermentable carbohydrates are a major etiological factor in the causation of etiological factor in the causation of caries.caries.

Cleansing nature of the diet :Cleansing nature of the diet : Accumulation of fermentable Accumulation of fermentable carbohydrates could be removed by carbohydrates could be removed by eating hard and fibrous foods (detersive eating hard and fibrous foods (detersive food).food).

Salivary stimulation effect of the dietSalivary stimulation effect of the diet : : Food that induce salivary flow keeps the Food that induce salivary flow keeps the mouth free of fermentation.mouth free of fermentation.

Sugar-Caries RelationshipSugar-Caries Relationship

The role of sugar in dental caries is The role of sugar in dental caries is related to:related to:

1.1. Frequency of consumption of sugars; Frequency of consumption of sugars; the risk increased if sugars are taken the risk increased if sugars are taken between mealsbetween meals..

2.2. The The frequency of consumption frequency of consumption is of is of major importance.major importance.

3.3. The nature of sugars; the risk is The nature of sugars; the risk is greatest if the sugar is in greatest if the sugar is in sticky formsticky form..

Environmental Risk Factors of Environmental Risk Factors of Dental CariesDental Caries

Oral hygiene practicesOral hygiene practicesPoor level of personal oral hygiene Poor level of personal oral hygiene

maintained by the individual is maintained by the individual is considered an important environmental considered an important environmental risk factor for dental caries.risk factor for dental caries.

Healthy oral hygiene practices include Healthy oral hygiene practices include thorough daily removal of dental plaque thorough daily removal of dental plaque and other debris by toothbrushing, and other debris by toothbrushing, flossing and mouth rinsing.flossing and mouth rinsing.

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