Dental caries is caused by acid-forming bacteria in dental plaque that are able to metabolize sugars. It is a dynamic process of demineralization and remineralization of tooth structure. Sites most prone to caries are those where plaque accumulates, such as pits and fissures. Risk factors include bacteria like Streptococcus mutans, frequency and amount of sugar consumption, age, gender, fluoride exposure, and oral hygiene. Saliva helps protect teeth through its washing, buffering, and remineralizing effects.

1. Epidemiology of
dental caries
Under supervision:
Dr/Eman Ramadan
Presented by:
Norhan Khaled
Mostafa Kamel
Nahla Abdelaziz
Menan Gamal
Rana Hani

2. Dental Caries
Dental caries is an infectious,
communicable disease resulting in
destruction of tooth structure by
acid-forming bacteria found in
dental plaque, in the presence of
sugar

3. Current concepts of
Dental Caries
The development of dental caries
is a dynamic process of
demineralization of the dental
hard tissues by the products of
bacterial metabolism, alternating
with periods of remineralization

4. Time
Tooth
Substrate
Microorganism
Current concepts of Dental Caries

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

7. Pit & fissure caries
• It is the first to appear in the
mouth.
•Pits &fissure surfaces constitute
the most susceptible surfaces in
the mouth.
Types of dental caries
Proximal caries
It is the next to appear in the
mouth.
• It is related to plaque
accumulation in the non-self
cleansing areas (beneath the
contact points).
Cervical caries
Is the third type of dental caries
that occurs uniformly throughout
life
•It is related to progressive
changes in the free gingival
margin,poor oral hygiene &
decreased salivary flow
(xerostomia)
Root caries
Occurs usually in old age (60 y<).
•Root surfaces become exposed
by gingival recession in advancing
age.
• These exposed areas provide
perfect areas for plaque
accumulation.

9. Index:
Is a graduated numerical scale with definite
upper and lower limits describing the relative
status of a population, designed to permit and
facilitate comparison with other populations
classified by the same criteria and methods.

10. The criteria for caries diagnosis should be defined
before starting the examination:
The commonest definition postulates that a tooth
is considered carious when a sharp explorer
catches in a cavity with a detectably soft floor
and/or some undermined enamel or a break-down
in the walls of a pit or fissure

12. Indices Used for Permanent Dentition :
Prevalence Index
• Slack Index
• DMFT
• DMFS
• Significant caries index

13. Indices for permanent dentition:

16. DMFT index of the individual = D+M+F
The maximum DMFT count is 28.
DMF Index of a group =DMF of all individuals / Total number of
examined individuals

17. Give score 5 for extracted posterior tooth and score 4 for extracted anterior
tooth.
Similarly, give score 5 for full coverage crown and score 4 for three quarter
crown.
The maximum DMFS count is 128 12X 4 + 16X 5 = 48 + 80 = 128

20. Indices Used for Primary Dentition:
*dmft
• dmfs

24. It is the disease of calcified
tissues.
It is a maltifactorial
disease in which the
following risk factors play
role in its
causation process:
1.Agent: Microorganisms
2.Host: Personal and
tooth risk factors.
3.Environment: Dietary, and
oral hygiene related risk
factors.
Dental Caries

25. 1.Streptococcus
mutans.
2.Lactobacilli.
3. Actinomyces.
1. Age.
2.Gender.
3.Race.
4.Genetic &familial.
5.Role of saliva.
6.Nutrition
7.Systemic diseases
and drugs.
1.Flouride.
2.diet.
3.Social factors.

26. AGE
Caries wasconsidered a
childhood disease because all
susceptible tooth surfaces
become carious during early
child years and few carious
lesions are affected during
adulthood
In communities with lower
attack rate, young people reach
adulthood with most surfaces
caries free and caries attack
spread out more throughout
life.
Caries increases progressively by age,
and the increase is more slowly
during adult years
• This is due to:
1.Most of the susceptible surfaces
are likely to have been attacked
by that time.
2. The build up fluoride in outer
layers of enamel over time.

27. It is observed that caries prevalence is higher in
females than in males of the same age
Females generally demonstrate higher DMF
scores than males probably due to :
1.The earlier tooth eruption in females; their teeth are at risk
for a longer time.
2.Females visit the dentist more frequently (treatment factor).
The impact of these determinant, however has not been
well quantified.

28. Early studies, observed that some races as those in Africa & India,
had high degree of caries resistance than “Europeans”.
Recently, the concept of racial differences have been faded, andthe
evidence reveals that the global differences are the result of
environment..
This was supported by the fact that these racial groups, once
thought to be resistant to caries (Africans and Indians), quickly
developed the disease when they moved to areas with different
cultural and dietary patterns.
The variation in caries prevalence is the result of environmental
ratherthan they are of racial attributes.

29. Scientific understanding of genetics and its role in caries has
advanced tremendously over the past 60 years, but remains quite
incomplete. Twin studies provide an interesting model for
determining the nature-vs-nurture aspects of caries, as most studies
show strong genetic contributions to caries experience.
Given the complex nature of dental caries, with the many diverse
contributing determinants of disease and genetic/ environmental
interactions, it is understandable that numerous genes are being
implicated in caries risk and resistance.
The goal of studies to determine potentially important genetic
factors is to allow more precise caries risk assessment, and,
ultimately, more targeted, personalized interventions that will
effectively prevent and manage the disease.

30. Saliva has a protective role against dental caries
through:
1-Washing action
2-Buffering action (Carbonic anhydrase in
bicarbonate system and phosphate system)
3-Antimicrobial action (Lysosomes & IGA)
4-Content of PO4 and Ca ions

31. Any condition causing disturbance of saliva formation and
composition, shift to caries inducing dietary pattern,
medicaments (with increased ferment. CHO, low pH or
affecting saliva), radiations (Xerostomia) also diseases of early
childhood affect Enamel formation
Including systemic (Autoimmune as Sjogern syndrome,
Endocrine as DM and Cystic fibrosis , neurologic and other ),
neurogenic (trigeminal & glossophayngeal ns), psychological
and local salivary glands diseases

32. Fluoride has a protective role against dental
caries through:

33. A. Systemic Fluoride Administration:
1. Fluoridation of water supply
2. Fluoridation of School water supplies
3. Fluoride supplements
4. Fluoride incorporation in various foods
B. Topical application :-
1. Brushing with fluoridated tooth paste
2. Fluoride mouth rinses
3. Fluoridated dental floss
4. Fluoride gel
5. APF foam

34. Diet is considered as one of risk factors (direct
related to bio-chemical process of caries
formation) for development of dental caries.
Diet can be classified according to their ability
to develop dental caries:
1- Cariogenic Nutrients :-
Carbohydrates, Mono, Di & polysacharides
2- Cariostatic Nutrients:- protein and fats
3- Carioprotective Nutrients :- Cheese & Dark
chocolate

35. Diet modification could be performed
through:
1- Diet counseling:-
Reducing the amount and frequency of
carbohydrtae intake
2- Sugar substitutes:
Xylitol and aspartame
3- Protective additives:- PO4

36. Low Socio-economy level increase risk as
increased cariogenic foods as being cheap,
saliva problems, reduced F support, Bad oral
hygiene and no regular dental check-up.
Poor economy may work in opposite
direction as Very poor population founds
no money for sweets

37. 3.. Agent Factors:
1. Bacterial factors:
Since the days of Miller, dental caries research has been
directed toward the identification of a microbial agent for
the disease.
At first, many workers, have drawn the attention to the
relation which appeared to exist between dental caries rate
and the number of lactobacilli, in the mouth.

38. Attention now centers on various groups of
streptococci.
The potential of certain strains of streptococci to
induce plaque and multisurface cavitation has been
conclusively established in animals and strongly
implicated in humans
1.Bacterial factors:

39. 2. Role of carbohydrates:
Freely fermentable carbohydrates have an
essential role in caries process.
Not all carbohydrates are equally condu-tive to
plaque formation and multisurface caries.

40. The rate of clearance from the mouth also affects
the rate by which bacteria may act upon
carbohydrates to produce acids.
Carbohydrates with rapid oral clearance seem to be
less dangerous than those which remain in the mouth
for a long time
2. Role of carbohydrates:

44. Thank You