All solid and liquid foods containing fermentable carbohydrates are potentially cariogenic. Acid-forming bacteria, such as caries-producing Streptococcus mutans, begin the immediate breakdown of sucrose from food, potentially contributing to dental caries. Sugars on the tooth surfaces are converted to acid within seconds of ingestion. The acid acts to demineralize the tooth. Left undisturbed, the acid produced from the ingestion of a sugar can remain in the oral cavity up to 2 hours. During this acid attack, the pH level of plaque drops from a normal range of 6.2-7.0 down to a pH of 5.2-5.5, the level at which demineralization can occur. Consumption of caries-producing solid and liquid foods will lower the oral pH to a level that makes the enamel susceptible to caries. These frequent exposures can lower the pH to demineralizing levels for several hours per day.
There is some intersting contrast concerning the nature and distribution of caries in adults, particularly older adults, as compared with children. Adults continue to experience primary dental caries, but they also experience a significant amount of secondary caries around existing restorations. Children today have comparatively few, if any restorations and experience mostly primary caries of the noncavitated type. Between 40 and 76% of dental carie in adults are arrested, a condition uncommoly observed in children.
Frequent , more than 3 times a day, snacking between meals, this increases the acid challenge to the teeth for a high level.
. The keystone of visual inspection of caries is based on the phenomenon of light scattering. Sound enamel is composed of densely-packed, modified hydroxyapatite crystals which give it a transparent structure. Hence, tooth colour is largely influenced by the underlying dentin shade. When enamel is disrupted in the presence of demineralization, the penetrating photons of light are scattered, which results in an optical disruption. In normal visible light, this appears as a ‘white spot’ – an area which looks whiter than the rest of the tooth. The appearance is enhanced in a dried lesion, as water has a similar refractive index (RI) to enamel, but air has a lower RI thus the lesion is more clearly seen. FOTI makes use of these optical properties of enamel and enhances them by using a high intensity white light shone through a small aperture (e.g. 0.3-0.5 mm) of a dental handpiece. The light that is shone through the tooth scatters and observed shadows may indicate the presence of a carious lesion. The reason why shadows may indicate caries is because demineralized areas of enamel or dentine scatter light more than sound areas. Hence, caries appear as darker areas under FOTI. (Pretty, 2006) The Method . However, the system is subjective. Analysis is done by the examiner who makes the call based on the appearance of scattering. There is also no continuous data output and it is not possible to record what is seen in the form of an image. Furthermore, FOTI can only be used for coronal tooth surfaces (occlusal, interproximal, and smooth) and not below the gingiva. (Pretty, 2006)
Preventive Dentistry I & II
Dr.Caroline Mohamed 1
Dr. Caroline Mohamed
The dental caries process
The role of diet in dental caries
Classification of dental caries
Incidence and prevalence and how can be
Dr.Caroline Mohamed 2
1. Dental caries definition
Dental caries is a multifactorial microbial disease
of the calcified tissues of the teeth, characterized
by demineralization of the inorganic portion and
destruction of the organic substance of the
tooth, which often leads to cavitations.
Dr.Caroline Mohamed 3
Two groups of bacteria are responsible for initiating
caries: Streptococcus mutans and Lactobacillus. If left
untreated, the disease can lead to pain, tooth loss,
infection, and, in severe cases, death.
Today, caries remains one of the most common
diseases throughout the world.
Cariology is the study of dental caries.
Dr.Caroline Mohamed 4
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
that may eventually develop into a large cavitation.
Sometimes caries may be directly visible, however
other methods of detection such as radiographs are
used for less visible areas of teeth and to judge the
extent of destruction.
Dr.Caroline Mohamed 5
Tooth decay is caused by specific types of acid-
producing bacteria that cause damage in the presence
of fermentable carbohydrates such as sucrose,
fructose, and glucose.
The mineral content of teeth is sensitive to increases
in acidity from the production of lactic acid.
Specifically, a tooth (which is primarily mineral in content)
is in a constant state of back-and-forth
demineralization and remineralization between the
tooth and surrounding saliva.
When the pH at the surface of the tooth drops below 5.5,
demineralization proceeds faster than
remineralization (meaning that there is a net loss of
mineral structure on the tooth's surface). This results
in the ensuing decay.
Dr.Caroline Mohamed 6
The role of diet in dental
Dr.Caroline Mohamed 10
Sucrose- arch criminal
Cariogenicity determined by
1. Frequency of ingestion
2. Physical form
3. Chemical composition-detergency
4. Texture of food
5. Presence of other constituents
Dr.Caroline Mohamed 11
Cariogenicity determined by
Frequency of ingestion
Tooth enamel dissolves at 5.5 ph
D Caroline Mohamed 14
Cow’s milk (cheese) contains calcium,
phosphorus, and casein
Wholegrain foods require more chewing
Peanuts, hard cheeses, and chewing gum
Black tea extract ( fluoride)
Dr.Caroline Mohamed 16
Depending on the extent of tooth destruction, various
treatments can be used to restore teeth to proper
form, function, and aesthetics, but there is no known
method to regenerate large amounts of tooth structure,
though stem cell related research suggests one
Instead, dental health organizations advocate preventive
and prophylactic measures, such as regular oral
hygiene and dietary modifications, to avoid dental
Dr.Caroline Mohamed 17
Definition of Epidemiology
The word epidemiology comes from the
epi , meaning on or upon
demos , meaning people, and
logos , meaning the study of
"the study of what is upon the people",
Incidence and prevalence and how can be
• Number or proportion of persons in a population affected
by a condition at a given point of time
• Can be expressed as, count, proportion or percentage.
Number of new cases of condition over a given point of
Change in prevalence or severity. The period of time depend
on time needed to disease to be observed
expressed as a rate (case per the population per time)
Determine the progress of condition
Dr.Caroline Mohamed 19
Different Age Groups
Key risk groups from ages
1 to 2 years ( baby bottle caries)
5 to 7 years ( primary caries)
11 to14 years
Key risk age group in young adults
and adults ( secondary caries/ root caries)
Sex- both sexes
early eruption in females
Adults continue to experience primary dental
caries, but they also experience a significant
amount of secondary caries around existing
Children today, in developed countries, have
comparatively few, if any restorations and
experience mostly primary caries of the
Between 40 and 76% of dental carie in adults are
arrested, a condition uncommoly observed in
Dr.Caroline Mohamed 21
Variation within dentition:
Dr.Caroline Mohamed 22
Early plaque formation occurs faster.
1.In lower jaw, compared to upper jaw.
2.In molars areas.
3.On buccal tooth surfaces, compared to oral sites.
4.In interdental regions compared to strict buccal
or oral surface.
Regularity of snaks, more than 3
times a day, snacking between
meals, this increases the acid
challenge to the teeth for a high
Nocturnal bottle usage- additive
On pacifier during sleep
(Kawaba et al., 1997)
Drinking sweet beverage
Brushing by mother
(Kawaba et al., 1997)
Dental Caries classification
1.based on anatomical site
2.based on progression
3.based on virginity of lesion
4.based on extend of caries
5.based on tissue involvement
6.based on chronology
7. based on whether caries is completely removed or not.
8.based on surfaces to be restored
9. WHO system
10.Caries risk Assessement
1) Based on anatomic site:
Crown caries Root caries
Pit & Fissure
Dr.Caroline Mohamed 35
Pits and fissures are anatomic landmarks on a tooth
where the enamel folds inward. Fissures are formed
during the development of grooves but the enamel in
the area is not fully fused.
As a result, a deep linear depression forms in the
enamel's surface structure, which forms a location for
dental caries to develop and flourish.
Fissures are mostly located on the occlusal surfaces of
posterior teeth and palatal surfaces of maxillary anterior
Dr.Caroline Mohamed 37
Pits are small, pinpoint depressions that are most
commonly found at the ends or cross-sections of
In particular, buccal pits are found on the facial
surfaces of molars. For all types of pits and fissures,
the deep infolding of enamel makes oral hygiene
along the surfaces difficult, allowing dental caries to
develop more commonly in these areas.
Dr.Caroline Mohamed 38
The occlusal surfaces of teeth represent 12.5% of all
tooth surfaces but are the location of over 50% of all
Among children, pit and fissure caries represent from
80 to 90% of all dental caries. Pit and fissure caries can
sometimes be difficult to detect.
As the decay progresses, caries in enamel nearest the
surface of the tooth spreads gradually deeper. Once the
caries reaches the dentin at the dentino-enamel junction
(DEJ), the decay quickly spreads laterally.
Dr.Caroline Mohamed 39
Within the dentin, the decay follows a triangle pattern
that points to the tooth's pulp. This pattern of decay is
typically described as two triangles (one triangle in
enamel, and another in dentin) with their bases conjoined
to each other at the DEJ.
This base-to-base pattern is typical of pit and fissure
caries, unlike smooth-surface caries (where base and
apex of the two triangles join).
Dr.Caroline Mohamed 41
Entry site may appear much smaller than actual lesion,
making clinical diagnosis difficult.
In cross section, the gross appearance of pit and fissure
lesion is inverted V with a narrow entrance and a
progressively wider area of involvement closer to the
a) Initially, caries of pit & fissures appears brown or
black in color & with fine explorer, it will feel soft & a
catch is felt ( don´t do it ).
b) The enamel which borders the pit & fissures appears
opaque bluish white.
Shape, morphological variation and depth of pit and
fissures contributes to their high susceptibility to caries.
The appearance of s.mutans in pits and fissures is
usually followed by caries 6 to 24 months later.
Sealing of pits and fissures just after tooth eruption
may be the most important event in their resistance to
Smooth surface caries
Smooth surface caries occurs on the gingival third of
the buccal, lingual & proximal surfaces.
• On proximal surface, caries begins below the contact area
& in early stage this appear as a faint white opacity of
enamel without loss of continuity of surface.
• As caries progresses, it appears bluish white in later
• Caries in cervical area are in the form of crescent
shaped cavities. It appear as a slightly roughened,
chalky area which gradually becomes deeper
Types of smooth surface caries
1. Proximal caries, also called interproximal caries,
form on the smooth surfaces between adjacent
2. Root caries form on the root surfaces of teeth.
3. The third type of smooth-surface caries occur on any
other smooth tooth surface. Less favorable site for
plaque attachment, usually attaches on the smooth
surface that are near the gingiva or are under
Proximal caries are the most difficult type to detect.
Frequently, this type of caries cannot be detected visually
or manually with a dental explorer.
Proximal caries form cervically (toward the roots of a
tooth) just under the contact between two teeth. As a
result, radiographs (bitewings) are needed for early
discovery of proximal caries.
Dr.Caroline Mohamed 47
Dr.Caroline Mohamed 48
In very young patients the gingival papilla completely
fills the interproximal space under a proximal
contact and is termed as col. Also crevicular spaces in
them are less favorable habitats for s.mutans.
Consequently proximal caries is less lightly to
develop where this favorable soft tissue architecture
Proximal surfaces Caries
The proximal surfaces are particularly susceptible to
caries due to extra shelter provided to resident
plaque owing to the proximal contact area
immediately occlusal to plaque.
Lesion have a broad area of origin and a conical, or
pointed extension towards DEJ.
V shape with apex directed towards DEJ.
After caries penetrate the DEJ softening of dentin
spread rapidly and pulpally
Root surface caries
The proximal root surface, particularly near the cervical
line, often is unaffected by the action of hygiene
procedures, such as flossing, because it may have
concave anatomic surface contours (fluting) and
occasional roughness at the termination of the enamel.
These conditions, when coupled with exposure to the
oral environment (as a result of gingival recession),
favor the formation of mature, caries-producing
plaque and proximal root-surface caries.
Root-surface caries is more common in older
patients. Caries originating on the root is
1. It has a comparatively rapid progression
2. it is often asymptomatic
3. it is closer to the pulp
4. it is more difficult to restore
Dr.Caroline Mohamed 54
Characteristics of root caries:
Root caries lesions have less well-defined margins,
tend to be U-shaped in cross sections, and
progress more rapidly because of the lack of
protection from and enamel covering.
When the gingiva is healthy, root caries is unlikely to
develop because the root surfaces are not as
accessible to bacterial plaque.
The root surface is more vulnerable to the
demineralization process than enamel because
cementum begins to demineralize at 6.7 pH, which is
higher than enamel's critical pH.
Regardless, it is easier to arrest the progression of root
caries than enamel caries because roots have a greater
reuptake of fluoride than enamel.
Dr.Caroline Mohamed 56
Root caries are most likely to be found on facial
surfaces, then interproximal surfaces, then lingual
Mandibular molars are the most common location to
find root caries, followed by mandibular premolars,
maxillary anteriors, maxillary posteriors, and
Dr.Caroline Mohamed 57
Progressive caries Arrested caries
Rapidly progressive - Acute Slowly progressive-
Nursing caries Radiation caries
2) BASED ON THE PROGRESSION OF THE LESION:
Acute caries is a rapid process involving a large number
These lesions are lighter colored than the other types,
being light brown or grey, and their caseous
consistency makes the excavation difficult.
Pulp exposures and sensitive teeth are often observed
in patients with acute caries.
It has been suggested that saliva does not easily
penetrate the small opening to the carious lesion, so
there are little opportunity for buffering or
Nursing caries can also be called as:
1. Nursing bottle caries
2. Nursing bottle syndrome
3. Milk bottle syndrome
4. Baby bottle tooth decay
5. Early childhood caries
The new name given for early childhood caries is
“maternally derived streptococcus mutans disease
Dr.Caroline Mohamed 60
This is the type of acute carious lesion,
which occurs among those children who
take milk or fruit juices by nursing bottle, for a
considerably longer duration of time, preferably during
As the child takes larger amount of easily fermentable sugars
along with the milk, the sugar facilitates the cariogenic bacteria
to produce caries at a rapid pace by fermenting those sugars.
Nursing bottle caries commonly occurs in the upper anterior
teeth (as these are constantly coming in contact with the
sweetened milk); while the lower teeth are not usually
affected as they remain under the cover of the tongue.
Radiotherapy is frequently associated with xerostomia
due to decreased salivary secretion
This and other cause of decreased salivation may lead to
a rampant form of caries, indicating the significance of
saliva in preventing caries.
Dr.Caroline Mohamed 62
Three types of defects due to irradiation
1. Lesion usually encircling the neck of teeth
amputation of crowns may occur
2. Begins as brown to black discolouration of
tooth .occlusal surface and incisal edges wear
3. Spot depression which spreads from any
These lesions are usually of long-standing
involvement, affect a fewer number of teeth, and are
smaller than acute caries.
Pain is not a common feature because of protection
afforded to the pulp by secondary dentin
The decalcified dentin is dark brown and leathery.
Pulp prognosis is hopeful in that the deepest of lesions
usually requires only prophylactic capping and
The lesions range in depth and include those that
have just penetrated the enamel.
Caries which becomes stationary or static and does not
show any tendency for further progression
Both deciduous and permanent affected.
With the shift in the oral conditions, even advanced
lesions may become arrested .
Arrested caries involving dentin shows a marked
brown pigmentation and induration of the lesion (the
so called ‘eburnation of dentin’).
Sclerosis of dentinal tubules and secondary dentin
formation commonly occur.
Exclusively seen in
caries of occlusal
surface with large
open cavity in which
there is lack of food
Also on the proximal
surfaces of tooth in
cases in which the
has been extracted
3) BASED ON THE VIRGINITY OF THE LESION:
Secondary or Recurrent
Recurrent caries is that occurring immediately next to a
restoration. It may be the result of poor adaptation of a
restoration, which allows for a marginal leakage, or it may be
due to inadequate extension of the restoration.
In addition, caries may remain if there has not been
complete excavation of the original lesion, which later may
appear as a residual or recurrent caries.
A primary caries is one in which the lesion constitutes the
initial attack on the tooth surface.
The designation of primary is based on the initial
location of the lesion on the surface rather than the
extent of damage.
This type of caries is observed around the edges and
The common locations of secondary caries are the rough
or overhanging margin and fracture place in all
locations of the mouth.
It may be result of poor adaptation of a restoration,
which allows for a marginal leakage, or it may be due to
inadequate extension of the restoration.
In addition caries may remain if there has not been
complete excavation of the original lesion, which later
may appear as a residual or recurrent caries.
4.Based on the extend of the lesion- severity
The early caries lesion best seen on the smooth surfaces
of the teeth, is visible as a ‘White Spot’
Histologically, the lesion has an apparently intact
surface layer overlying subsurface demineralization.
Significantly many such lesions can under go
remineralization & thus the lesion is not an
indication for restorative treatment
Remineralised with fluoride application
D/d: developmental defects of enamel
Dr.Caroline Mohamed 76
Occult or hidden caries is used to describe such lesion,
which is not clinically diagnosed but detected only on
It is believed that bitewing & OPG radiographs along with
other noninvasive adjuncts like fibrooptic
transillumination (FOTI), LASER luminescence,
electrical resistance method(ERM) are used for
diagnosing these occlusal lesions.
Prevalence-0.8%-50% in age range of 14 -20 yrs
Dr.Caroline Mohamed 78
Once it reaches the
dentinoenamel junction, the
caries process has the
potential to spread to the
pulp along the dentinal
tubules and also spread in
Thus some amount of
sensitivity may be
associated with this type of
This may be generally
accompanied by cavitation
5. Based on tissue involvement
1. Initial caries- demineralization
2. Superficial caries- enamel
3. Moderate caries- dentin caries
4. Deep caries – dentin close to the pulp
5. Deep complicated caries – pulp involvement
Dental caries can be divided into 4 or 5 stages
1. Initial caries: Demineralization without structural
This stage can be reversed by fluoridation and
enhanced mouth hygiene
2. Superficial caries (Caries superficialis):Enamel
caries, wedge-shaped structural defect.
Caries has affected the enamel layer, but has not
yet penetrated the dentin. Includes larger lesions
with adequate tooth structure to support the
3. Moderate caries (Caries media): Dentin caries. Extensive
structural defect. Caries has penetrated up to the
dentin and spreads two-dimensionally beneath the
enamel defect where the dentin offers little resistance.
4. Deep caries (Caries profunda): Deep structural defect.
Caries has penetrated up to the dentin layers of the tooth
close to the pulp.
5. Deep complicated caries (Caries profunda complicata)
:Caries has led to the opening of the pulp cavity (pulpa
aperta or open pulp).
6. Based on chronology
Early childhood caries
Early childhood caries would include, two variants:
Nursing caries and rampant caries.
The difference primarily exist in involvement of the
teeth (mandibular incisors) in the carious process in
rampant caries as opposed to nursing caries.
Teenage caries (adolescent caries)
This type of caries is a variant of rampant caries
where the teeth generally considered immune to
decay are involved.
The caries is also described to be of a rapidly
burrowing type, with a small enamel opening.
The presence of a large pulp chamber adds to the
woes, causing early pulp involvement.
With the recession of the gingiva and sometimes
decreased salivary function due to atrophy, at the
age of 55-60 years, the third peak of caries is
Root caries and cervical caries are more commonly
found in this group.
Sometime they are also associated with a partial
7.Based on whether caries is completly
removed or not during treatment
Residual caries is that which is not removed during a
restorative procedure, either by accident, neglect or
Sometimes a small amount of acutely carious dentin
close to the pulp is covered with a specific capping
material to stimulate dentin deposition, isolating
caries from pulp.
The carious dentin can be removed at a later time.
8.Based on surfaces to be restored
Most widespread clinical utilization
O for occlusal surfaces
M for mesial surfaces
D for distal surfaces
F for facial surfaces
B for buccal surfaces
L for lingual surface
Various combinations are also possible, such as MOD
–for mesio-occluso-distal surfaces.
9.World health organization (WHO)
In this classification the shape and depth of the caries
lesion scored on a four point scale
D1. clinically detectable enamel lesions with intact
D2. Clinically detectable cavities limited to enamel
D3. Clinically detectable cavities in dentin
D4. Lesions extending into the pulp
10. Assessement tools
Stepwise progression toward diagnosis & treatment
planning depends on thorough assessment of the following
Conventional techniques of measuring
and recording decay
Dr.Caroline Mohamed 93
Mirror and explorer
Detection of white spot, discoloration / frank
Unable to detect subsurface caries.
Magnification loupes- Head worn prism loupes (X 4.5)
or surgical microscopes (X 16) may be used.
Use of temporary elective tooth separation.
Use of explorer is not advocated because;
Sharp tips physically damage small lesions with
Probing can cause fracture & cavitation of incipient
lesion. It may spread the organism in the mouth.
Mechanical binding may be due to non-carious
reasons Shape of fissure
Sharpness of explorer
Force of application
Path of explorer placement
Explores should be used to clean debris
+ non –destructive
+ can detect subsurface caries
- limited safety
- unable to detect incipient
- low resolution
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Dr.Caroline Mohamed 97
Radiographic imaging of pit and fissures is of
minimal diagnostic value because of the large
ammount of sorrounding enamel enamel.
It is detrimental if used for non-invasive
Direct fiberoptic transillumination
Enhanced visual technique that uses the principle of
illuminating teeth to detect the presence of caries.
. (Pretty, Maupomé, 2004)
Dental Caries Index DMF-T
Decayed, Missed, Filled Teeth
D = Decayed / not treated yet
M = Missed / extracted because decayed
F = Filled / restored after decay
T = Permanent teeth
dmf-t = Primary teeth
S = Surface
DMF-S / dmf-s
( Mesial/ Distal/ Vestibular
Dr.Caroline Mohamed 102
CLASS 1: pit and fissure cavities that occur in the
occlusal surfaces of bicuspids and molars, the
occlusal two thirds of the buccal and lingual
surfaces of the molars, and the lingual surfaces of
Cavities beginning in structural defects that
occasionally occur on the occlusal or incisal two
third of all teeth.
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CLASS 2: cavities in the proximal surfaces of bicuspids
Dr.Caroline Mohamed 104
CLASS 3: Cavities in the proximal surfaces of incisors
and cuspids, not involving the incisal angle
Dr.Caroline Mohamed 105
CLASS 4: Cavities in the proximal surfaces of incisors
and cuspids involving the incisal angle
CLASS 5: Cavities in the gingival third, not pit and fissures
cavities, of the labial, buccal and lingual surfaces of all
Dr.Caroline Mohamed 107
CLASS 6: Cavities on both mesial and distal proximal
surfaces of bicuspid and molars that when restored
will share a common isthmus; or cavities on the
incisal edges of anterior or cusp tip of posterior
HIGH RISKHIGH RISK LOW RISKLOW RISK
Social HistorySocial History
Socially deprivedSocially deprived
High caries in siblingsHigh caries in siblings
Low knowledge of cariesLow knowledge of caries
Middle classMiddle class
Low caries in siblingLow caries in sibling
High dental aspirationsHigh dental aspirations
Medical HistoryMedical History
Medically compromisedMedically compromised
Long-term cariogenicLong-term cariogenic
No such problemNo such problem
Dietary habitsDietary habits
Sugar intake: frequentSugar intake: frequent InfrequentInfrequent
HIGH RISKHIGH RISK LOW RISKLOW RISK
Use of fluorideUse of fluoride
Non-fluoridated areaNon-fluoridated area
No fluoride supplementsNo fluoride supplements
Fluoridated areaFluoridated area
Fluoride supplements usedFluoride supplements used
Plaque controlPlaque control
Poor oral hygienePoor oral hygiene
Good oral hygieneGood oral hygiene
Low flow rate& bufferingLow flow rate& buffering
↑↑ S.mutans & lactobacillusS.mutans & lactobacillus
Normal flow rate& bufferingNormal flow rate& buffering
↓↓ S.mutans & lactobacillusS.mutans & lactobacillus
HIGH RISKHIGH RISK LOW RISKLOW RISK
Clinical evidenceClinical evidence
New lesionsNew lesions
Premature extractionsPremature extractions
Anterior caries restorationsAnterior caries restorations
No fissure sealantsNo fissure sealants
Multi-band orthodonticsMulti-band orthodontics
No new lesionsNo new lesions
No extraction for cariesNo extraction for caries
Sound anterior teethSound anterior teeth
No/few restorationsNo/few restorations
Fissure sealedFissure sealed
No appliancesNo appliances