DENTAL CARIES

HISTOPATHOLOGY AND
PREVENTION
PRESENTATION BY:SANDEEP REDDY J
MDS 1ST YEAR
DEPARTMENT OF CONSERVATIVE AND ENDODONTICS
KRISHNADEVARAYA COLLEGE OF DENTAL SCIENCES AND
HOSPITAL
CONTENTS

• Introduction
• Enamel caries
• Zones of enamel caries
• Dentinal Caries
• Prevention of dental caries
• Conclusion
• Bibliography
 Introduction

“Dental caries is an irreversible 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 cavitation”

CARIES – Latin ‘dry rot’

Simple definition – Irreversible, slow progressing decay of hard
tissues of tooth.

WHO – Localized post eruption , pathologic process of external

origin involving softening of hard tooth tissue and proceeding to
the formation of a cavity.
Newbrun 1982
HISTOPATHOLOGY OF CARIES -
ENAMEL

• Caries process in enamel

progresses through following
stages
A. Early submicroscopic lesion
B. Phase of nonbacterial enamel
crystal destruction
C. Cavity formation
D. Bacterial invasion of enamel
* C & D Occur almost simultaneously
EARLY LESION – SMOOTH
SURFACE
• Earliest visible changes are seen as a
chalky white spot on the tooth just
adjacent to contact point.
• Electron microscopic study reveals
the early changes as loss of inter rod
enamel, accentuation of striae of
Retzius and perikymata.
• As caries progresses, the lesion of
smooth surface caries has a
distinctive conical shape with its
base towards enamel surface and
apex towards DEJ.
• This conical lesion when observed
in a light microscope reveals four
different zones as seen from
deepest advancing zone first
1. Translucent zone 2. Dark zone
3. Body of lesion 4. Surface zone
1.TRANSLUCENT ZONE: -

• Unrecognizable clinically &

radiologically.
• Occurs due to formation of
submicroscopic pores at enamel
rod boundaries.
• This zone is slightly more porous
than sound enamel having a pore
volume of 1% compared to 0.1%
of sound enamel.
 2. Dark Zone

•Lies superficial to translucent zone.

•Called positive zone. Dark zone shows positive birefringence in
contrast to negative birefringence of sound enamel
•Pore volume is 2 – 4%.
3. BODY OF LESION: -

• Forms bulk of the lesion and

lies between relatively
unaffected surface zone and
dark zone.
• Area of greatest
demineralization, having a pore
volume of 5% near the
periphery to about 25% in the
center of body of lesion.
• Quinoline Transmitted Translucent
light
• Water Polarized light Positive
birefringence
 4. SURFACE ZONE:
-
• Interestingly, this zone not only
remains intact during the early
stages of attack by caries, but
also REMAINS MORE
HEAVILY MINERALIZED.
• Pore volume of only 1%.

• Ions for remineralization come either from those within plaque or

from reprecipitation of calcium and phosphate ions diffusing outwards
as deeper layers are demineralized.
• Eventually, this zone is demineralized by the time caries penetrates
dentin.
Water Quinoline Viewed dry under
as medium of imbition as medium of imbition polarized light
HISTOPATHOLOGY OF CARIES –
DENTIN (EARLY CHANGES)
• The initial (non infected) lesion in dentin
forms beneath enamel before any
cavity has formed.
• Even though acids formed from
fermentation of carbohydrate substrate
diffuse into dentin, they leave the organic
matrix intact.
• Once bacteria penetrate enamel, they
spread laterally along DEJ and attack
dentin over a wide area.
• The infected lesion of dentin is helped
in its course by the presence of
tubules within dentin which provide
an easy pathway to the bacteria.

• Bacteria now liberate proteolytic

enzymes and bring about destruction
of organic matrix of dentin which is
already softened by demineralization.
• The first change to occur in the caries process within dentin is
fatty degeneration of the tome’s fibers, with deposition of lipid
globules within these fibers.
• This is then followed by dentinal sclerosis, which is minimal in
rapidly advancing acute caries and maximum in slow, chronic
caries.
• This is considered as a protective measure by dentinal tubules to
seal off the invading bacteria.
• In spite of all these attempts to prevent
spread of caries process, dentin is
continually destroyed.
• Thus behind the zone of dentinal sclerosis a
narrow zone of decalcification is seen,
just ahead of bacterial invasion of dentinal
tubules.
• At this stage, only a few tubules are invaded
even before clinical evidence of caries.
• These bacteria are called “Pioneer bacteria”.
HISTOPATHOLOGY OF CARIES –
DENTIN (ADVANCED CHANGES)

• Continued decalcification of
dentinal tubules leads to their
confluence, although the
structure of organic matrix may
still be maintained for some
time.
• Confluence of tubules occurs
due to packing of the tubules
with the invading bacteria.
• The coalescence and breakdown
of adjacent dentinal tubules leads
to formation of “Miller’s
liquefaction foci”.

• It is an ovoid area of destruction

of tubules parallel to the course of
tubules and is packed with
necrotic debris derived from
destruction of tubules.
• Continued dentinal destruction by
decalcification followed by proteolysis
occurs at many focal areas which
ultimately coalesce to form a necrotic
leathery mass of dentin.
• In this mass, clefts occur at right
angles to tubules and parallel to the
course of lateral branches of tubules
or along the collagen fibers of organic
matrix.
• Due to these clefts, carious dentin can
be peeled away in thin layers by hand
instruments.
ZONES OF DENTINAL CARIES

• Observing from the pulpal side at the

advancing edge of carious lesion
following different zones can be seen
–
5 ZONE 1 – Zone of fatty degeneration of
4 Tomes’ fibers
3
2 ZONE 2 – Zone of dentinal sclerosis
1
ZONE 3 – Zone of decalcification
ZONE 4 – Zone of bacterial invasion
ZONE 5 – Zone of decomposed dentin
ZONES OF DENTINAL CARIES
 Overview

 Need for prevention

 Aims of prevention
 Levels of prevention
 Methods to control caries
 Current methods of prevention
oral health care
NEED FOR PREVENTION
 Symptomatic treatment is intensive
 The cost of treatment is high
 Compromises nutrition
 Results in dysfunctional speech
 Causes severe pain
AIMS OF PREVENTION
 Limiting pathogen growth
and metabolism
 Limitation of caries activity
 Early detection of incipient
caries
 Identification of high risk
patients
LEVELS OF PREVENTION
 Primary prevention
 Secondary prevention
 Tertiary prevention
 LEVELS OF PREVENTION
1. Primary prevention
 Actions taken prior to the onset of the disease,
which removes the possibility that the disease
will ever occur.
 By plaque control programme, caries activity
test, patient education, topical application, pit
and fissure sealants.
 LEVELS OF PREVENTION
2. Secondary prevention
 Limits the progression and extent of a disease at
as early stage as possible after onset.
 By preventive resin restoration, pulp capping.
 LEVELS OF PREVENTION
3. Tertiary prevention
 Limits the extent of disabilities once a
disease has caused any functional
limitation.
 By complex restorative dentistry.
Caries Management by Risk
Assessment
(CAMBRA)

30
 Low Risk
Criteria-Low Risk

• No dental caries within last 3 years

• Minimal or no visible plaque
• Sealants or shallow pits & fissures
• Usually has regular dental care
• Often lives in a fluoridated
environment or uses one or more
fluoride containing products.

31
 Moderate Risk
Criteria-Moderate Risk
• visible HEAVY plaque on teeth
• Frequent snacking
• > 3x daily between meals
• Deep pits & Fissures
• Exposed Roots
• Mild to moderate xerostomia
• Orthodontic appliances
• Recreational drug use

32
 High Risk
Criteria-High Risk
• Visible cavities
• Radiographic caries
• Radiographic penetration of the
dentin
• advanced or severe lesion from any
position of the tooth (occlusal or
interproximal)
• Radiographic interproximal enamel
lesions (moderate)
• White spots lesions on smooth surfaces
• Restorations in the last 3 years 33
 Extreme Risk
Criteria-EXTREME Risk

• Severe salivary gland hypofunction

(salivary rate less than 0.5 ml per minute)
• Visible cavities
• Radiographic lesions
• advanced or severe lesion involving
most of dentin from any position of the
tooth (occlusal or interproximal)
• Radiographic interproximal enamel
lesions (moderate)
• White spots on smooth surfaces
• Restorations in the last 3 years 34
CAMBRA – Therapeutic Product Guide

35
 METHODS TO CONTROL
CARIES
 Chemical methods
 Nutritional methods
 Mechanical methods
 METHODS TO CONTROL
CARIES
1. Chemical methods
 Substances which :
• Alter the tooth surface or structure.
• Interfere with carbohydrate degradation
through enzymatic alteration.
• Interfere with bacterial growth and metabolism.
 CHEMICAL METHODS
1.Alter the tooth surface or
structure
Fluorides
 Iodides
 Bisbiguanides
 Silver nitrates
 CHEMICAL METHODS
FLUORIDES
Mechanism:
• Precipitates fluorapatite
• Remineralisation
• Mineralisation on hypomineralised areas
• Interferes with bacterial enzymatic process
• Modifies tooth morphology
 CHEMICAL METHODS
FLUORIDES
 Delivery Methods
• Fluoridated community water
• School water fluoridation
Systemic
• Salt and milk fluoridation
• Fluoride tablets and drops

• Professionally or Self applied

• Dentifrices
Topical • Mouth rinses
• Varnishes and gels
SYSTEMIC FLUORIDES
 TOPICAL FLUORIDES
1.Professionally applied :-
 Prophylactic paste
• In high risk caries patients
• Clean and supply fluoride in one step
• Contain zirconium silicate abrasive
 TOPICAL FLUORIDES
1.Professionally applied Cont... :-
Fluoride solutions
• Sodium fluoride
• Stannous fluoride
• APF
 TOPICAL FLUORIDES
1.Professionally applied Cont... :-
Fluoride gels
• Acidulated phosphate fluoride gel (APF)
 TOPICAL FLUORIDES
1.Professionally applied Cont... :-
Fluoride varnishes
• Provide high uptake of fluoride into enamel
• Cost effective
 TOPICAL FLUORIDES
2. Self applied :-
 Fluoride dentifrices
• Sodium fluoride
• Stannous fluoride
• Sodium monofluorophosphate
 TOPICAL FLUORIDES
2. Self applied :-
 Fluoride mouthrinses
• Sodium fluoride
• APF
• Along with topical or
systemic application
 CHEMICAL METHODS
CHLORHEXIDINE
Bisbiguanide
Antiseptic
Antibacterial
 CHEMICAL METHODS
Disadvantages of fluorides & bisguanides :
• Stains teeth
• Bacterial resistance
• Bitter taste
• Mucosal irritation
• Allergic reaction
 CHEMICAL METHODS
2. Interfere with carbohydrate
degradation through enzymatic
alteration

 Vitamin K: Prevents acid formation in mixtures

of glucose and saliva
 Sarcoside: sodium-N-lauryl sarcosinate and
sodium dehydroacetate
 CHEMICAL METHODS
3. Interfere with bacterial
growth and metabolism
Urea and ammonium compounds:
• Anticariogenic agents
• Gram positive bacteria
 Chlorophyll:
• Reduces the pH fall
 CHEMICAL METHODS
3. Interfere with bacterial
growth and metabolism
Nitrofurans:
• Bacteriostatic and bactericidal
• Aerobic and anaerobic bacteria
 Antibiotics:
• Penicillin,Erythromycin,Kanamycin
 Caries vaccines
 NUTRITIONAL METHODS
 Restriction of refined
carbohydrate intake
 Avoiding sugar in
between meals
 Phosphated diet
 NUTRITIONAL METHODS
Foods with anticariogenic
effects:
• Milk- contain lactose (least cariogenic)
• Cheese- casien phosphatase
• Fibrous foods- raw vegetables,grains
• Sugar substitutes & artificial
sweetners -
xylitol,mannitol,sorbitol
• Tea- green and black tea
 XYLITOL
Xylitol is 5 carbon sugar that has same
sweetness as sucrose but not fermented by
MS
Prevents Streptococcus mutans from
binding to sucrose
Neutralises plaque acids
Increases salivary flow
Bacteriostatic
Enhance remineralisation
 DENTAL EROSION
Dietary acids
Soft drinks, fruit juices,
vinegar
Prevention: Not to brush
teeth for atleast 1 hr after
consumtion of such foods
and drinks.
MECHANICAL METHODS
 Oral prophylaxis
 Tooth brushing
 Interdental cleaning aids
 Disclosing agents
 Oral irrigators
 Detergent foods
 Salivary stimulants
 Pit and fissure sealants
 ORAL PROPHYLAXIS
 Decreases the formation of dental plaque
by careful polishing
 Scaling
 TOOTH BRUSHING
Types :
• Manual
• Powdered
• Sonic and ultrasonic
• Ionic
Methods :
• Modified bass method
• Charters method
• Circular method
• Sulcular method
 TOOTH BRUSHING
SULCULAR METHOD
INTERDENTAL CLEANING
AIDS
Dental floss :
• To remove plaque and dislodged
irritating matter
• Nylon,yarn,teflon
• Waxed or unwaxed
• Where interdental papillae fill the
interdental spaces
INTERDENTAL CLEANING
AIDS
Dental floss
INTERDENTAL CLEANING
AIDS
 Wooden sticks:
• Soft, triangular,
wooden toothpicks.
• In patients with
gingival recession
INTERDENTAL CLEANING
AIDS
Interdental brushes:
• Cone shaped brushes
• In patients with wide
interdental spaces
INTERDENTAL CLEANING
AIDS
 Single tufted brushes:
• Single tuft
• In areas of malalignment
 DISCLOSING AGENTS
Solutions, tablets or
wafers.
Erythrosin
Stains bacterial plaque
 ORAL IRRIGATORS
 Flushing devices
A 3 second treatment of
pulsating water (1,200
pulses per minute) at
medium pressure (70 psi)
removed 99.9% of plaque
biofilm from treated areas.

Gorur, A; Lyle, DM; Schaudinn, C; Costerton, JW (2009). "Biofilm removal with a

dental water jet". Compendium of continuing education in dentistry. 30 Spec No
 DETERGENT FOODS
 Fibrous food prevents lodging of food
 SALIVARY STIMULANTS
 Sugar free chewing
 Ascorbic Acid (Vitamin C)
 Malic acid
 Pilocarpine
 PIT AND FISSURE
SEALANTS
 Dental resin
 Isolates pit and
fissures
Types:
• GIC
• Resin sealants
 CURRENT METHODS
 Lasers
 Genetic modalites
 Polymeric coatings
 Caries vaccines
 Active and passive
immunisation
 LASERS
Laser irradiation enhances acid resistance of
enamel surfaces and prevent caries
progression. Combined use of topical fluoride
application and laser irradiation (by CO2,
Nd:YAG, or argon lasers) on sound enamel
surfaces provided the best protection against
caries initiation and progression
 GENETIC MODALITIES

Organisms
• Strains of streptococcus mutans that lack lactate
dehydrogenase
Food:
• Fruits
• Interfere with enzymatic pathways of
streptococcus mutans
 CARIES VACCINES
 Stimulates production of protective antibodies.

The corporation Planet Biotechnology has developed a

synthetic antibody against S. mutans, branded CaroRx, which it
produces using transgenic tobacco plants. This product may be
considered a therapeutic vaccine, applied once every several
months, and is in Phase II clinical trials as of October 2007.
 INFANT ORAL HEALTH
CARE
Guidelines to parents :
• Should bring their child for his/her
first dental visit.
• Avoid frequent use of bottles with
sugar containing milk or drinks
{nursing bottle caries}
• Clean the gums and later teeth with
soft brush after every meal or before
sleep.
- It is imperative that we, as dentists
should focus on treating not only those
who are ill, but also treat those who
are more likely to get ill…
 BIBLIOGRAPHY

 Shafer WG, Hine MK, Levy BM. A text book of oral

pathology. 6th ed. Elsevier

 Cawson, R.A: Cawson’s Essentials of Oral

Pathology and Oral Medicine,
8th Edition

 Ghom, Ali & Mhaske, Shubhangi: Textbook of

Oral Pathology

 Comprehensive Preventive Dentistry by Dr. Hardy

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