dental caries

1. Lesions affecting
hard tissue of the
teeth
By
Dr. Nuha Elkadiki
(BDS , MDS)

3. DENTAL CARIES:
Also known as tooth decay, cavities, or caries, is a
breakdown of teeth due to activities of bacteria. The
cavities may be a number of different colors from yellow
to black. Symptoms may include pain and difficulty with
eating. Complications may include inflammation of the
tissue around the tooth, tooth loss, and infection or
abscess formation.

4. Destruction of a tooth by dental caries. This type of decay is
also known as root decay.

5. History
– By 17 century ,there was a significance increase in dental caries
lesion ,involving interproximal area of tooth , today the dental
caries is virtually universal disease, extensive studies have done to
illustrate the influence of the civilization on the dental caries.
– However .its noticed that isolated population that have no or
acquired habits of modern industrialized man retain free of caries.

6. Epidemiology
– Worldwide, approximately 36% of the population have dental caries in their
permanent teeth. In baby teeth it affects about 9% of the population. The disease
is most common 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 adults over the age of 50 experience caries.

7. Epidemiology
– The number of cases has decreased in some developed countries, and this decline is usually
attributed to increasingly better oral hygiene practices and preventive measures such as
fluoride treatment.Among children in the United States and Europe, 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 others having a high number.Australia, Nepal, and Sweden (where
children receive dental care paid for by the government) have a low incidence of cases of
dental caries among children, whereas cases are more numerous in Costa Rica and
Slovakia.

8. Epidemiology
– The classic DMF (decay/missing/filled) index is one of the most
common methods for assessing caries prevalence as well as dental
treatment needs among populations. This index is based on in-field
clinical examination of individuals by using a probe, mirror and
cotton rolls. Because the DMF index is done without X-ray
imaging, it underestimates real caries prevalence and treatment
needs.

9. Factors affecting caries prevalence
1. Race : some studies show a remarkable difference in caries
experience between a various race . American black and white living
in the same geographic area under the same condition . On
comparison the black people have the fewer caries lesion than white.
2. Age :several studies show that at the age of 6 years ,about 20%
experienced caries.
3. Genders :several studies indicated the caries index in the permanent
teeth is greater in female than male.

10. Factors affecting caries prevalence
4. Familial :
Sibling of individual with high caries activity are also generally caries
active .and children's of parents with low caries activity also have
low caries activity.

11. Caries susceptibility of jaw quadrants
– Dental caries experience was found to be higher in maxillary arch ,
and this was related to the fact that the saliva with its buffering
action would tend to drain from upper teeth and collect in the lower

12. Caries susceptibility of individual
tooth surface
– HAYATT and LOTKA(1929) studied carious involvements of a
various tooth surface in 2934 patient under age of 25 , the data
indicated that the caries on the occlusal surface is more than other
surface

13. Classification of dental caries:
– Based on the location of the caries.
– Based on the speed of the caries progression.
– Based on whether it is new or recurrent caries.
– Based on the extent of the caries.
– Based on the pathway of the caries spread with in the tooth.
– Based on the number of the tooth surface involved.
– Based on the treatment and the restoration design.

14. Classification of dental caries:
– Based on the location of the caries:
1. Pit and fissure caries
a) Occlusal ,buccal and lingual surface of
posterior teeth.
b) Lingual surface of maxillary anterior teeth.
1. Smooth surface caries
2. Root surface caries.

15. Classification of dental caries:
– Based on the speed of the caries progression.
1. Acute or Rampant caries: rapidly involved caries,involving several
teeth ,appear soft and light in color.
2. Chronic caries: Slowey progressive long standing caries, hard in
consistency and dark in color.
3. Arrested caries : sometime chronic lesion can become arrested due to
change in the local environment , this appear dark brown in color and hard
in consistency

18. Classification of dental caries:
– Based in weather carious lesion is new or recurrent :
1. Initial or primary caries : first attack of caries on tooth
structure .
2. Secondary or recurrent caries(Residual) : caries seen
under or around margins of restoration

19. Classification of dental caries:
– Based on the extent of the caries:
1. Incipient caries or white spot ; first evidence of caries
activity in enamel , it consist ,it consist of demineralized enamel which has
not extended to DEJ , the enamel surface is still hard and still intact
.incipient caries can be demineralized.
2. Cavitated caries : caries spread beyond in to dentin , the enamel
surface is break down and demineralized is not possible , it is referred as
irreversible caries .

20. – Incipient: Lesion that extends less than halfway through the enamel
– Moderate: Lesion that extends more than halfway through enamel but does not
involve the dentino-enamel junction (DEJ)
– Advanced: Lesion that extends to or through the DEJ but does not extend more
than half the distance to the pulp
– Severe: Lesion that extends through enamel, through dentin, and more than
half the distance to the pulp

23. Classification of dental caries:
– Based on the pathway of the caries spread with in
the tooth:
1. Forward caries: whenever the caries cone in enamel is larger or
same size as in dentin ,its referred as forward caries.
2. Backward caries: when ever the spread of caries along the DEJ ,
exceed the caries cone in enamel , its referred as backward caries.

24. Classification of dental caries:
– Based on the number of the tooth surface involved:
1. Simple caries: involve only one surface.
2. Compound caries: involve two surface .
3. Compound caries: involve three or more surface.

25. Classification of dental caries:
- Based on the treatment and the restoration design:
1. Caries lesion on occlusal area, lingual pit and buccal
area on the tooth surface.

26. Classification of dental caries:
– Based on the treatment and the restoration design:
2. Carious lesion on the posterior occlusal and
interproximal surface of the tooth

27. Classification of dental caries:
-Based on the treatment and the restoration design:
3. Carious lesion on the anterior interproximal
surface of the tooth

28. Classification of dental caries:
-Based on the treatment and the restoration design:
4. Carious lesion on the anterior interproximal surface
of the tooth including incisor corners.

29. Classification of dental caries:
- Based on the treatment and the restoration design;
5. Carious lesion on the gingival third of the crown
on facial or lingual surface of the teeth

30. Classification of dental caries:
- Based on the treatment and the restoration design;
6. Carious lesion on the tip of the cusp of the posterior
teeth :

31. Classification of dental caries:
– Based on the age of the patient :
1. Nursing bottle caries: during early infancy, bottle fed babies
develop rapidly spreading caries usually on maxillary incisors.
2. Adolescence caries: acute caries is also frequency seen in the
teenager population die to dietary habits .
3. Senile caries: carious occur on the elderly population , is mostly
characterized by involvement of root surface. This happened because of
gingival recession coupled with other factors like reduced salivation
and poor oral hygiene.

32. Classification of dental caries:
– Based on the tooth surface to be involved :
1. O : occlusal surface.
2. M: mesial surface.
3. D: distal surface.
4. B: buccal surface.
5. L:lingual surface.
MOD=mesial occlusal and distal surface

33. Causes of dental caries
1. Tooth surface (enamel or dentin),
2. Caries-causing bacteria,
3. Fermentable carbohydrates (such as sucrose),
4. Time.

34. Causes of dental caries
– This involves adherence of food to the teeth and acid creation by
the bacteria that makes up the dental plaque. Tooth decay is caused
by biofilm (dental plaque) lying on the teeth and maturing to
become cariogenic (causing decay). Certain bacteria in the biofilm
produce acid in the presence of fermentable carbohydrates such as
sucrose, fructose, and glucose. Caries occur more often in people
from the lower end of the socioeconomic scale than people from
the upper end of the socioeconomic scale

35. Causes of dental caries
- Biofilm is not adherent food debris .
- Survival of microorganism in the oral environment depends on their
ability to adhere to a surface ,only a few specialized organisms,
primarily streptococci, are able to adhere to oral surfaces such as
the mucosa and tooth structure

36. Causes of dental caries
– Bacteria
The most common bacteria associated with dental cavities are the mutans
streptococci, most prominently Streptococcus mutans and Streptococcus
sobrinus, and lactobacilli. However, cariogenic bacteria (the ones that can
cause the disease) are present in dental plaque, but they are usually in too low
concentrations to cause problems unless there is a shift in the balance.[24]
This is driven by local environmental change, such as frequent sugar, no
biofilm removal (a lack of tooth-brushing)

37. Causes of dental caries
a wider variety of bacteria can cause root caries, including Lactobacillus
acidophilus, Actinomyces spp., Nocardia spp., and Streptococcus mutans.
Bacteria collect around the teeth and gums in a sticky, creamy-coloured mass
called plaque, which serves as a biofilm. Grooves on the occlusal surfaces of
molar and premolar teeth provide microscopic retention sites for plaque
bacteria, as do the interproximal sites. Plaque may also collect above or
below the gingiva, where it is referred to as supra- or sub-gingival plaque,
respectively.

39. Causes of dental caries
– The tooth surface is stable and covered with the pellicle of
precipitated salivary glycoproteins, enzymes, and
immunoglobulins.
– It is the ideal surface for the attachment of many oral
streptococci.
– If left undisturbed, biofilm rapidly builds up to sufficient
depth to produce an anaerobic environment adjacent to the

41. Causes of dental caries
– Dietary sugars
Bacteria in a person's mouth convert glucose, fructose, and most commonly
sucrose (table sugar) into acids such as lactic acid through a glycolytic process
called fermentation. these acids may cause demineralization, which is the
dissolution of its mineral content. The process is dynamic, however, as
remineralization can also occur if the acid is neutralized by saliva or mouthwash.
Fluoride toothpaste or dental varnish may aid remineralization.[28] If
demineralization continues over time, enough mineral content may be lost so that
the soft organic material left behind disintegrates, forming a cavity.

42. Causes of dental caries
– Exposure
The frequency with which teeth are exposed to
cariogenic (acidic) environments affects the
likelihood of caries development.[30] After meals or
snacks,

43. Causes of dental caries
– Teeth
There are certain diseases and disorders affecting
teeth that may leave an individual at a greater risk
for cavities(amelo-genesis imperfecta).

44. Causes of dental caries
– Other factors
1. Reduced salivary flow rate (Sjögren's syndrome,
diabetes mellitus, diabetes insipidus,) Medications,
such as antihistamines and antidepressant.
2. The use of tobacco may also increase the risk for
caries formation, Some brands of smokeless tobacco
contain high sugar content, increasing susceptibility
to caries

45. Pathophysiology
– Teeth are bathed in saliva and have a coating of bacteria on them (biofilm)
that continually forms. The minerals in the hard tissues of the teeth (enamel,
dentin and cementum) are constantly undergoing processes of
demineralization and remineralisation. Dental caries results when the
demineralization rate is faster than the remineralisation and there is net
mineral loss. This happens when there is an ecologic shift within the dental
biofilm, from a balanced population of micro-organisms to a population that
produce acids and can survive in an acid environment

46. Pathophysiology
Dental caries is the result of the formation of dental plaque
which harbors the bacteria which in turn fermentate the
carbohydrate available in daily food and producing acids , the
production of acid in turn decrease the pH below 5 ,prolonged
exposure to pH below 5 lead to demineralization of tooth
structure with which it come in contact with

47. Pathophysiology
Saliva act as a neutralizing agent to increase pH
level , which may lead to remineralization in most
cases.

50. Pathophysiology
– Enamel
is a highly mineralized acellular tissue, and caries act upon it through a
chemical process brought on by the acidic environment produced by
bacteria. The effects of this process include the demineralization of crystals
in the enamel. Enamel rods, run perpendicularly from the surface of the
tooth to the dentin. follows the direction of the enamel rods, the different
triangular patterns between pit and fissure and smooth-surface caries
develop in the enamel because the orientation of enamel rods are different
in the two areas of the tooth

52. Pathophysiology
– 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. The
translucent zone is the first visible sign of caries and coincides with a one to
two percent loss of minerals. A slight remineralization of enamel occurs in
the dark zone, The area of greatest demineralization and destruction is in the
body of the lesion itself. The surface zone remains relatively mineralized and
is present until the loss of tooth structure results in a cavitation.

54. Pathophysiology
– Dentin
Unlike enamel, the dentin reacts to the progression of dental caries. After tooth
formation, the ameloblasts, which produce enamel, are destroyed once enamel
formation is complete and thus cannot later regenerate enamel after its
destruction. On the other hand, dentin is produced continuously throughout life
by odontoblasts, which reside at the border between the pulp and dentin. Since
odontoblasts are present, a stimulus, such as caries, can trigger a biologic
response. These defense mechanisms include the formation of sclerotic and
tertiary dentin.

55. Pathophysiology
tin
Dentin

56. Caries diagnosis and assessment
– Visual examination.
– Enhanced visual examination.
a) Trans-illumination.
b) Fibre-optic trans-illumination.
c) Magnification.
– Dyes.
– Radiographic examination.
– Laser fluorescence.
– Electrical conduction methods

57. Caries diagnosis and assessment
Visual inspection: of the tooth is the first and most widely used
method; however it may be inaccurate. The tooth must be clean, dry
and well illuminated when carrying out a visual examination. A
blunt probe may be useful to clean debris off the tooth surface or
gently feel for cavities; however, a probe, blunt or otherwise, must
not be pushed against the tooth surface (especially into fissures) as
there is the risk of causing cavitation of delicate early demineralized
lesions.

59. Caries diagnosis and assessment
– Enhanced visual examination:
Trans-illumination
This uses an intense beam of visible light, usually directed on
the lateral surface of the tooth to trans-illuminate it and aid
with caries diagnosis. This technique is most useful in the
diagnosis of anterior approximal caries and cracked teeth.

60. Caries diagnosis and assessment
Enhanced visual examination:
Fibre-optic trans-illumination
This technique uses a fibre-optic light source placed palatal
to anterior teeth to aid diagnosis of anterior approximal
caries. With the increased number of fibre-optic hand-pieces
available, it is feasible to have a fibre-optic tip attached to
dental units.

64. Caries diagnosis and
assessment
Enhanced visual examination:
Magnification”
This is most commonly in the form of
magnification loupes, to aid with clinical
examination and radiographic evaluation

65. Caries diagnosis and assessment
Enhanced visual examination:
Dyes
A variety of different dyes that stain caries are currently available. These
help to make the visualization of caries easier. However,

67. Caries diagnosis and assessment
Enhanced visual examination:
Radiographic examination

68. Caries diagnosis and assessment
Enhanced visual examination:
Laser fluorescence
Caries illuminated by a laser will fluoresce, the degree to which
this occurs is an indicator of the disease process. However, heavy
fissure staining can affect the degree of laser fluorescence.

69. Caries diagnosis and assessment
Enhanced visual examination:
Electrical conduction methods
This principle is based on electrical conductance and the fact that sound
enamel is a good electrical insulator; however, carious teeth (with
porosities) allow the passage of an electrical current more readily,
resulting in a drop in the electrical resistance. The degree to which the
resistance drops is an indicator of the extent of caries.

70. Role of saliva in prevention of
dental caries
– Bacterial clearance .
– Direct antibacterial activity .
– Buffering capacity .

71. Role of saliva in prevention of
dental caries
Bacterial clearance .
– The flushing effect of this salivary flow is, by itself, adequate to
remove virtually all microorganisms not adherent to an oral surface .
– Adults produce 1-1.5 L of saliva a day, very little of which occurs
during sleep.

72. Role of saliva in prevention of
dental caries
Direct antibacterial activity .
 Salivary glands produce an antimicrobial products ,Lysozyme,
lactoperoxidase, lactoferrin, and agglutinins possess antibacterial activity .
 Although the antibacterial proteins in saliva play an important role in
the protection of soft tissue in the oral cavity from infection by
pathogens, they have little effect on caries because similar levels of
antibacterial proteins can be found in caries-active and caries-free
individuals.

73. Role of saliva in prevention of
dental caries
Buffering capacity .
 The buffering capacity of saliva is determined primarily by the
concentration of bicarbonate ion.
 The benefit of the buffering is to reduce the potential for acid
formation.
 In addition to buffers, saliva contains molecules that contribute to
increasing biofilm pH. These include urea and sialin, Hydrolysis of
either of these basic compounds results in production of ammonia,
causing the pH to increase

74. Prevention of caries:
1. Regular cleaning of the teeth(Brushing the teeth
twice per day and flossing between the teeth once a
day is recommended by many).
2. small amounts of fluoride(Fluoride may be from
water, salt , tablets or toothpaste) .

77. Prevention of caries:
2. small amounts of fluoride(Fluoride may be from
water, salt or toothpaste) . That fluoride
incorporated in enamel and form fluorapatite that’s
more resistance to decay

78. Prevention of caries:
3. Diet
Decreasing the frequency of fermentable carbohydrate
consumption and elimination or substitution is essential
as this will result in reduced periods of acid production
and less risk of demineralization of the tooth tissue.

83. Preventive treatment methods are designed to limit tooth
demineralization caused by cariogenic bacteria, preventing cavitated
lesions. These methods include
(1) limiting pathogen growth and altering metabolism,
(2) increasing the resistance of the tooth surface to demineralization,
and increasing biofilm pH.
A caries prevention and management program is a complex process
involving multiple interrelated factors
Prevention of dental caries

84. Prevention of dental caries
1. Oral hygiene procedures (tooth brushing and flossing) Chemical agents
for plaque control e.g. chlorhexidine with 0.12% mouth rinse at bed
time for at least 2 weeks.
2. Restricted the ingestion of fermentable carbohydrates. And Minor
dietary changes such as substitution of sugar-free foods for snacks are
more likely to be accepted than more dramatic changes.(diet control)
3. Determined the general condition of patient (The effectiveness of a
patient’s immune system depends on overall health status. Patients
undergoing radiation or chemotherapy treatment have significantly
decreased immunocompetence and are at risk for increased caries).

85. Basic treatment procedure for remineralization
therapy is divided into:
→ 1st phase: directed towards reduction of habitat for S. Mutans
by : restoring active lesion and sealing of pits & fissures
→2nd phase: short period of topical fluoride treatment.
Prevention of dental caries

86. Fluoride Therapy
1. Fluoride is incorporated into hydroxyl apatite making it more acid resist enhances
remineralization process.
2. Inhibit action of glycosyl Transferase enzyme → preventing polymerization of
sucrose in to extra cellular polysaccharides & ↓ of plaque bacteria adherence to tooth.
3. Topical F application is toxic to some microorganism
4 Alter surface energy of E → less susceptible to bacteria adhesion.
5. F ↓ transportation of glucose into bacteria cell.
Prevention of dental caries

87. FLOURIDE TREATMENT MODALITIE
1) Systemic appl. Water fluoridation 1ppm.
2) Topical application. self or professional appl.
A) Self application: stannous fl 40% as gel on brush /on tray, or
mouth rinse (Naf .05- 0.2 (%
B) Professional application: *Periodic appl. In high caries risk
patients using acidulated phosphate gel 1.23% in tray. Or fluoride
varnish. *Topical appl. Using iontophoresis .
Prevention of dental caries

88. Placement of sealants
1) Used for prevention of pits & fissure caries.
2) Applied to posterior teeth shortly after their eruption.
Method of application:-
* Teeth isolation.
* Prophylaxis or air abrasion is performed → clean surface
* Etching ě 37% H2PO4 for 30sec. then rinsing & drying. *check for etching….
presence of frosty appearance.
* Slightly filled resin is applied into etched surface followed by curing for 20sec.
*check the occlusion.
Prevention of dental caries

89. Enameloplasty
Definition→ It is the process of reshaping the enamel surface with suitable
rotary cutting instrument.
Indication → when a pit or fissure
a( It doesn’t penetrate to any great depth in the enamel.
b( It doesn’t allow Proper preparation of the cavity margins except by
undesirable extension
– Technique :
A shallow fissure is removed and the convolution of E is saucered areas
become → cleansable.
Prevention of dental caries

90. Treatment of dental caries

91. Non carious lesion
1. Abrasion
Abnormal tooth surface loss resulting from direct forces of friction
between teeth and external objects or from frictional forces between
contacting teeth components in the presence of an abrasive medium.
occur from
(1) improper brushing techniques, (2) habits such as holding a pipe stem
between teeth, (3) tobacco chewing, or (4) vigorous use of toothpicks
between adjacent teeth.

92. 2. Erosion Is the wear or loss of tooth surface by chemico- mechanical action
Cause :
 Regurgitation of stomach acid can cause this condition on the lingual surfaces of maxillary teeth .
 Dissolution of the facial aspects of anterior teeth because of habitual sucking on lemons or the loss of tooth surface
from ingestion of acidic beverages

93. 3. Attrition Is the mechanical wear of the incisal or occlusal surface
as a result of functional or para-functional movements of the mandible
(tooth-to-tooth contacts). Attrition also includes proximal surface wear
at the contact area because of physiologic tooth movement.

94. 4. Abfraction: It has been proposed that the
predominant causative factor of some cervical,
wedge-shaped defects is a stronger eccentric
occlusal force idiopathic erosion.

95. 3. Attrition Is the mechanical wear of the incisal or occlusal surface
as a result of functional or para-functional movements of the mandible
(tooth-to-tooth contacts). Attrition also includes proximal surface wear
at the contact area because of physiologic tooth movement.

96. 5. Fractures
INCOMPLETE FRACTURE NOT DIRECTLY INVOLVING VITAL PULP
An incomplete fracture not directly involving vital pulp is often termed a
“greenstick” fracture. This phenomenon is caused by excessive cyclic loading (or
traumatic injury) from occlusal .

97. The fracture begins in enamel, but becomes painful following propagation into
dentin. This condition is very sensitive, and yet the patient may only be able to tell
which side of the mouth is affected rather than the specific tooth. It is, therefore,
sometimes challenging to diagnose and treatment

98. COMPLETE FRACTURE NOT INVOLVING VITAL PULP This
represents complete separation of a fragment of the tooth structure in
such away that the pulp is not involved. Usually, pain is not associated
with this condition, unless the gingival border of the fractured
segment is still held by periodontal tissue. Restorative treatment
(sometimes along with periodontal treatment) is indicated.

99. FRACTURE INVOLVING VITAL PULP
Fracture involving vital pulp always results in pulpal infection