pulp dentin

1. PULPODENTINAL
COMPLEX
PRESENTED BY
UPAMA SISHAN

2. CONTENTS
DENTIN
• INTRODUCTION
• PHYSICAL PROPERTIES
• CHEMICAL PROPERTIES
• STRUCTURE
• TYPES OF DENTIN
• DENTINOGENESIS
• AGES CHANGES
• DEVELOPMENTAL
ANOMALIES
• CLINICAL CONSIDERATIONS
• REFERENCES
PULP
• INTRODUCTION
• MORPHOLOGY
• DEVELOPMENT OF PULP
• ZONES OF PULP
• CELLS IN PULP
• AGES CHANGES
• CLINICAL
CONSIDERATIONS
• REFERENCES

3. Dentin and pulp are embryologically, histologically, and
functionally the same tissue and therefore are considered
as a complex
Orbans(1980) stated that “The pulp
lives for the dentin and the dentin
lives by the grace of the pulp. Few
marriages in nature are marked by a
greater interrelationship. Thus it is
with the pulp and the four functions
that it serves: namely, the formation
and the nutrition of dentin and the
innervation and defense of the
tooth.”
Based on this Nanci (2005)has stated that
the pulp and dentin can no longer be
studied as two separate entities but must
be viewed as the pulp-dentin complex.

4. • Hard tissue portion of the pulp-
dentin complex the bulk of the
tooth
• First formed
• Formation begins in late bell stage
• Formed by odontoblasts
• Bound to enamel at DEJ & to
cementum at CEJ
• Consists of large no of small
parallel tubules in a mineralized
collagen matrix.
• Vital, nonliving
DENTIN

5. HISTORY
1771 – JOHN HUNTER – hard tissue
1775 – ANTON VON LEEUWENHOEK –tubular structures
1837 – PURKINJE & RETZIUS explained about dentinal tubules
CUVIEN gave the name IVORY to dentin
1891- VON EBNER GAVE THE TERM- ebners growth
lines or imbrication lines
1906 – VON KROFF GAVE THE TERM –von kroffs fibres.

6. Physically and chemically the dentin resembles bone
The main morphologic difference between bone & dentin

7. Physical properties
COLOUR - PALE YELLOW
SPECIFIC GRAVITY – 2 .14
MODULUS OF ELASTICITY – 15-20 GPA
HARDNESS – 64GN/m² 296GN/m²
COMPRESSIVE STRENGTH – 262 MN/m² 76MN/m²
TENSILE STRENGTH – 33MN/m² 46MN/m²
STIFFNESS – 12 MN/m² 131MN/m²
RADIOOPACITY – LESS THAN ENAMEL

8. INORGANIC
70%
WATER
10%
ORGANIC
20%
CHEMICAL COMPOSITION:

9. INORGANIC
CALCIUM HYDROXYAPATITE
Ca10(PO4)6(OH)2
thin plates
smaller than enamel
SALTS:
calcium carbonate
sulphate, phosphate etc
TRACE ELEMENTS
Cu, Fe, F, Zn
ORGANIC
COLLAGEN
82%,mainly type I
Traces of type III
Non collagenous
Matrix proteins
18%
Enymes
Lipids

10. Organic component:

11. STRUCTURE OF DENTIN:
Dentinal tubules:
• dentine is permeated by dentinal tubules.
• run from pulpal surface to DEJ & CEJ.
• tubules indicates the course taken by the odontoblasts during
dentinogenesis.
PRIMARY CURVATURE
• tubules follow an S- shaped path
• results from the crowding of & path followed by odontoblasts
as they move towards the centre of the pulp.
• First curve towards apex, second towards crown
• In root dentin- little or no crowding- tubules run in a straight
course

12. Dentinal Tubules
Coronal dentin
Root dentin

13. Secondary curvature of DT
Secondary curvatures:
tubules also show changes in direction of smaller
amplitude(a few micrometers), observed under higher
magnification.

14. Terminal branches:
• more profuse in root dentin than in coronal dentin.
• show a Y shaped terminal branching.
• Dentinal tubules are tapered shape
• larger near pulp- 2.5 µm in diameter
• smaller at DEJ- 1 µm or less
TUBULE POPULATION:
Approx;
20000/mm² – towards DEJ
30000/mm²-75000/mm² – towards the pulp
Lateral branches:
• tubules show lateral branches , almost 45 degree to
main tubule, may contain O. Process, may
communicate with adjacent ones or blindly end in
intertubular dentin.

15. Lamina limitans
Dental lymph
Odontoblastic
process Nerve fibers
CONTENTS OF DENTINAL TUBULES:

16. ODONTOBLASTIC PROCESS
Cytoplasmic extensions of
odontoblasts
larger in diameter near pulp- 3-4µm
narrower near DEJ – 1 µm
3 hypothesis – pulpward
migration of odontoblast as
dentine is deposited:

17. ENAMEL SPINDLES:

18. Types of Dentin
Dentin
Primary physiologic
dentin
Secondary physiologic
dentin
Tertiary dentin or
reparative dentin or
reactionary dentin or
irregular secondary dentin
Mantle
dentin
Circumpulpal
dentin
Intratubular
dentin
Intertubular
dentin

20. (1) MANTLE DENTINE
• First formed dentine in crown
• Underlying DEJ
• 20 µm thick
• Fibrils are perpendicular to DEJ
• Organic matrix – von korffs
fibres(large dia fibrils-type III
collagen fibrils)
• Less mineralized compared to
circumpulpal dentine.
• Matrix vesicles involved in
mineralization.
• Globular mineralization
PRIMARY DENTINE
Formed before root completion
Consists of mantle dentine and circumpulpal dentine
(2) CIRCUMPULPAL
DENTINE:
• Circumpulpal dentin
forms the remaining
primary dentin or bulk of
the tooth.
• The fibrils are much
smaller in diameter
(0.05micrometer) & are
more closely packed
together.
• Slightly more mineral
content than mantle dentin.

21. SECONDARY DENTIN
• narrow band of dentin
bordering the pulp
• forms after root formation is
complete
• it is a slow continous
deposition of dentin
• Contains fewer tubules than
primary dentin
• It is formed more slowly
than primary dentin
TERITIARY DENTIN
• Reactive, Reparative, Irregular
dentin.
• Produced in reaction to various
stimuli.
• Quality and quantity depends
on intensity and duration of
stimulus.
• Tubules may or may not be
present
• Cells may be included in
dentin referred to as
osteodentin.

22. STIMULI
ODONTOBLASTS DIE FEW ODONTOBLAST
SURVIVE
MIGRATION OF
UNDIFFERENCIATED
CELLS FROM PULP TO
DENTIN
REPAIRATIVE DENTINE REACTIONARY DENTINE

23. Types Of Reparative Dentin
Atubular dentin ( area
without dentinal tubules)
Osteodentin (entrapped cells).
Vasodentin
(entrapped b.v.)

24. PERITUBULAR DENTIN
• Wall of dentinal tubules
• Highly mineralised
• Lost during decalcification
• overproduced – SCLEROTIC DENTIN
Other name:
INTRATUBULAR DENTIN:
Depositon of the minerals occurs in the inner wall of the
tubule rather on the outer wall, the term intratubular dentine is
considered more appropriate.
15% more mineralized than intertubular dentin.
Lacks collagenous fibrous matrix.

25. INTERTUBULAR
DENTINE:
• Located between the dentinal
tubules
• the primary end product of the
odontoblasts.
• fibrils are arranged at roughly rt
angles to the DT.
• FIBRILS 0.5 – O.2
micrometres in diameter.
• Less calcified
• Bulk of dentin
• Retained after decalcification

26. Dentinal tubules
intratubular dentin Intertubular dentin

27. PREDENTIN
 located adjacent to the pulp tissue.
 is the mineralising front of the dentin.
 Always present throughout life.
 because mineralization process lags behind
matrix deposition.
 2 to 6 microns thick, depending on the activity
of the odontoblast.

28. Interglobular dentin
Areas of hypomineralized dentin where
globular zones of mineralization
(calcosperites) have failed to fuse into a
homogenous mass within mature dentin.
• seen in the circumpulpal dentin just
below the mantle dentin.
• The dentinal tubules pass
uninterruptedly, thus demonstrating a
defect of mineralization & not of
matrix formation.
• Appear dark in transmitted light &
bright under reflected light- ground
sections.

29. GRANULAR LAYER:
• In root dentin adjacent to CDJ, when viewed
under transmitted light in ground sections
(LS) a granular layer can be seen.
• Caused by coalescing and looping of the
terminal portions of the dentinal tubules
HYALINE LAYER:
Outside the granular layer is a clear hyaline
layer.
Upto 20µm wide
Usually included as`a component of the
dentine.
May serve to bond cementum to dentine.

30. Structural lines in dentine
2 groups of lines:
(1)lines associated with primary and secondary curvature of
dentinal tubules.
(a) Schreger lines (primary curvature)
(b)contour lines of owen (secondary curvature)
(2)lines arising from the incremental deposition of dentine
and its subsequent mineralization.
(a) incremental lines of von ebner (short period lines)
(b) Andersons line (long period lines)

31. CONTOUR LINES OF OWEN:
• coincidence of the secondary
curvatures between the neighbouring
dentinal tubules.
• Some of the incremental lines are
accentuated because of disturbances
in the matrix and mineralization
process.
• Seen in ground sections as
hypocalcified bands.
NEONATAL LINE:
• Represents an exxagerated contour line of
owen & shows the changes in
physiology(nutritional, hormonal, etc.) that
occur at birth.
• Seen in primary teeth & the first permanent
molars.
• Dentine distal to dis line(nearer to DEJ) -
formed prior to birth & the dentine proximal
to it(nearer to the pulp - formed after birth.

32. The incremental lines (von ebner), or
imbrication lines or short period line,
 appear as fine lines or striations in dentin.
 Seen as alternating dark & light bands.
 run at right angles to the dentinal tubules.
 Reflect the diurnal rhythm of dentine
deposition as well as hesitation in the
daily formative process.
 Cuspal dentine - 4µm/day(rapid
deposition)
 Root dentine - 2µm/day(slower)

33. ANDERSONS LINES (long period lines)
• the term long period refers to the intrinsic temporal repeat interval
that is greater than one day (in contrast to daily short period line).
• 16 - 20µm apart
• Between each long period line there are 6 – 10 pairs of short period
lines.
• Cause for the 6 to 10 day periodicity is unknown.

34. AGE AND FUNCTIONAL CHANGES IN
DENTINE
1. VITALITY OF DENTIN:
• Odontoblasts & its processes are an integral part of dentin.
• Reacts to physiologic and pathologic stimuli.
• As age advances , the ability of dentine to respond to stimuli
decreases.
3. TERITIARY DENTIN:
2. SECONDARY DENTIN:
• The size of the pulp cavity decrease & obliteration of the
pulp horns

35. 4. SCLEROTIC
DENTIN:
• Dentinal tubules
become occluded
with calcified
material.
• When this occurs in
several tubules the
dentin assumes a
glassy appearance.
• Found specially in
radicular dentin
(apical 3rd).
• Transparent or
light in transmitted
and dark in
reflected light.

36. 5. Dead tracts
Tubules affected by caries may
fill with bacteria
odontoblast processes may
disintegrate or retract
Leaving behind an empty space-
dead tract
Dead tracts can occur due to death
of odontoblasts from crowding (in
pulpal horns).
• In ground sections appear black in
transmitted light because they
entrap air.
• Probably the initial step in the
formation of sclerotic dentin

37. Dentinoenamel
junction
• Its found in the form of
series of scallops
• increases the adherence
between dentin and enamel.
• More pronounced in coronal
dentin where occlusal stress
is more.
• Shape & nature prevents
shearing of enamel

38. Dentino-cemental junction
• Firm attachment
• Smooth in permanent teeth
• Scalloped in primary teeth
• Intermediate zone- hyaline layer of
hopewell smith- cements the cementum to
dentin
• Product of HERS

39. DENTAL PAPILLA CELLS (LATE BELL
STAGE)
CYTODIFFERENCIATION OF
ODONTOBLASTS
DEPOSITION OF ORGANIC MATRIX
MANTLE PREDENTIN APPEARS
MINERALIZATION PHASE
CIRCUMPULPAL DENTIN(PRIMARY
DENTINE)
ROOT DENTIN
SECONDARY DENTINE
DENTINOGENESIS
1. Odontoblast
Differentiation
2. Matrix Formation
3. Good Vascular Supply
4. Mineralization
Two phase mechanism:

40. Odontoblasts differentiation

42. Odontoblastic process formation
At first more than one
process
As more D is laid down, the cells
receed and leave single process.

43. Odontoblast become a protein forming and secreting cell.
• R E R , Mitochondria and Golgi bodies
• Ribonucleic acid and alkaline phosphatase
Inner dental
Predentin
epith side
Large open
faced N
R E R
Mitochondria
Golgi
bodies

44. Matrix formation
• A- Mantle dentin
• The first formed dentin
layer in crown
• And root
Fibers are perpendicular to
D E J
Fibers are parallel to
basement membrane

45. B) Circumpulpal dentin
Mantle dentin
Circumpulpal
dentin. The fibers
are parallel to DEJ (
right or oblique
angle to DT)
Crowding of the
cells and
appearance of
junctional complex

46. MINERALIZATION PATTERN
 Histologically 2 patterns seen
1. Globular calcification
2. Linear calcification
Globular calcification
• Deposition of crystals in discrete areas of matrix by heterogeneous capture
in collagen
• globules enlarge & eventually fuse to form single calcified mass.
• as in mantle dentin formation
Linear calcification
• Rate of formation slow- mineralization front apperas more uniform
• The process is said to be linear.
• Example-circumpulpal dentin

47. Mineralization
Budding of
matrix vesicles Rupture of matrix
vesicles
Mineralization of the
mantle dentin
Has
membrane
rich in
alkaline
phosphatase
Calcium and
phosphate ions
undergo
crystallization
Matrix
vesicle

48. • DPP conc elevated - inhibits mineralization
• OSTEONECTIN – it can inhibit HA crystals growth & promote Ca
& phosphorous binding to collagen
• OSTEOPONTIN – promotes mineralization
• CHONDROITIN SULPHATE – properties vary depending on
whether they are in:
PREDENTINE- prevent transport and diffusion of
crystals(inhibitors)
MINERALIZING DENTINE - promote hydroxyapatite crystal
formation.

49. ROOT DENTIN DEVELOPMENT
• Initiated by HERS
• Space btwn initial collagen
fibres & HERS become filled
with an amorphous ground
substance with fibrillar non
collagenous matrix secreated by
root sheath(10µm).
• Collagen fibres laid down
parallel to CEJ.

50. VASCULAR SUPPLY during dentinigenesis
 Good supply - imp during secretory phase
 Mantle dentin formation - capillaries are seen in
subodontoblastic area.
 Circumpulpal dentin formation - capillaries migrate between
odontoblasts and endothelium fenestrates.
 After dentinogenisis is completed - capillaries retreat and
endothelial lining becomes continuous

51. DENTINOGENESIS IMPERFECTA
DENTIN DISORDERS
Autosomal dominant condition
Type I & Type II:
Tulip shaped teeth, bluish grey –
yellow/brown.
enamel chips off--- expose dentin, rapid
attrition.
Type III
Amber appearance, excessive wear,
multiple pulp exposures.

52. Dentin dysplasia:
Regional odontodysplasia:
- Maxillary anteriors affected.
- Delay or total failure in eruption.
- Irregular shape
- H/P:
Reduction in amount of dentin
widening of predentin layer
large areas of interglobular dentine.
irregular tubular pattern
Rx: extraction and replacement by a prosthetic
appliance
ROOTLESS TOOTH
• Normal enamel
• Atypical dentin
• Abnormal pulp morphology
Type I (RADICULAR)
- coronal dentin normal
- root dentin shows osteodentin,
fused denticles, tubular dentin
Type II (CORONAL)
- multiple pulp stones in pulp
- relatively normal coronal dentin.

53. DENTIN PERMEABILITY
Depends upon patency of dentinal tubules
Reduced permeability
Decreased sensitivity
Tubular
occlusion
Smear layer
formation
CLINICAL CONSIDERATIONS:

54. M
I

55. CARIES OF THE DENTIN
Histologically , 5 zones of early dentinal caries progression can be seen
(listed pulpally to occlusally):

56. Pit and fissure
caries
• Follows the
direction of
dentinal tubules
• Triangular shape
• With base at DEJ
and apex at the
outer surface
• Greater no of
dentinal tubules
will be involved
when the lesion
reaches DEJ.

57. ADHESION OF DENTAL MATERIALS TO DENINE:
SMEAR LAYER – when dentine is cut with a dental bur, a smear layer is formed consisting of
dentine that has been melted & reset.
ADVANTAGE: it occludes the dentinal tubules
DISADVANTAGE: may harbour bacteria
before applying bonding agents , the smear layer should be removed.
Tags of resin in a restorative
material(arrows) conforming
to the dentinal tubules in
etched dentine and enhancing
retention of the restoratiion.

58. (A)PULP has lost its odntoblast layer and is
replaced by a vascular granulation tissue
(B) DENTINE is undergoing resorption by large
multinucleated odontoclast – like cells

59. Radiograph of tooth showing
external dentine resorption.
The presence of radioopaque layer
of dentine internally helps
distinguish this case from one of
internal dentine resorption.

60. OPERATIVE INSTRUMENTATION
Dentin – treated with care during op.instrumentation to
prevent damage to the odontoblasts
AVOID
EXCESSIVE CUTTING
HEAT GENERATION
CONTINUOUS DRYING
USE
AIR WATER COOLANT
SHARP HAND INSTRUMENTS
TUNGSTEN CARBIDE BURS to cut vital dentin-
less heat generation

61. FORENSIC ODONTOLOGY
IDENTIFICATION OF AN UNKNOWN CORPSE IN
DISASTERS FROM DENTAL DNA:
Tooth pulp – best source of dental DNA
- DENTIN and cementum are also sources.
- method- cryogenic grinding
Long period(anderson) lines in
root dentine is used to calculate
age at death.
The extent of aspartic acid
racemisation in dentin – a reliable
marker for estimating age at
death.

62. SMART DENTINE GRINDER
STEPS:
1 - Extracting the tooth & Cleaning
debris
2- Grinding the tooth with a specially
designed grinder into particulate dentin
3- Cleaning particulate dentin by a
chemical cleanser, resulting in
bacteria-free bone graft
4- Grafting-
The result is a particulate dentin two to
three times the volume of the original
root

63. Elephant ivory is solid dentin.
The structure of the dentinal tubules contributes to both its porosity and
its elasticity.
Elephant tusks are formed with a thin cap of enamel, which soon wears away,
leaving the dentin exposed.

64. PULP
The pulp is a soft connective tissue of
mesenchymal origin residing within the pulp
chamber and root canal of teeth (Cohen).

65. Anatomy of Pulp
Pulp Chamber or coronal
pulp, located in the crown
of the tooth.
Root canal or radicular pulp,
is the portion of the pulp
located in the root area.
The apical foramen is the
opening from the pulp at the
apex of the tooth.
Accessory canals or lateral
canal, extra canal located on
the lateral portions of the
root.
Pulp horns

66. LATERAL CANALS AND ACCESSORY CANALS
According to the glossary of American Association of Endodontists, lateral and
accessory canals are differentiated as
Lateral canal
Is a canal that is located at approximately at right angles to main root canal
Accessory canal
Is the one that branches off from main root canal,usually in the apical region of the
root.
Accessory foramina
Are the openings of the accessory and lateral canals on the root surface
Mechanism of formation accessory canals
1- it occurs in areas, where the developing root encounters a large
blood vessel, where dentin will be formed around it.
2- Early degeneration of the epithelial HERS before the
differentiation of the odontoblasts.

67. APICAL DELTA:
It is a triangular area
of root surrounded by
the main canal,
accesory canals and
periradicular tissues.
• Difficult to instrument & obturate
• If not visible in radiograph, it
may be left untreated.
• Recent thermoplasticized root
canal filling- like obtura &
thermofill obturate these variation
more successfully.

68. DEVELOPMENT OF PULP:
Begins at the 8th week of embryonic life.
Inner enamel epithelium
(Signalling molecules)
Dental papilla cells undergoes cytodifferenciation into a peripheral
layer of odontoblasts & central mass of fibroblasts
Once odontoblasts have begun to lay down dentine
Dental papilla becomes dental pulp

69. Small undifferenciated ectomesenchymal cells of dental papilla (less
intercellular material)
Synthetic organnelles appear, cytoplamic component of cells expands,
Materials that the organelles produce is released into the extracellular
space & forms the collagen fibres that are embedded in amorphous
ground substance.
• 18th week of IU Life nerve fibres are seen in dental papilla.
• Dental pulp cells during development produces nerve growth factors
and semaphorin 7A & brain derived glial cell line derived
neurotrophic factor.
• All these helps to innervate the pulp.
• Young dental papilla is highly vascularized during dentinogenesis.

70. FUNCTIONS OF PULP:
INDUCTIVE Induce oral epithelial differentiation into dental lamina and enamel
organ formation. Also induces developing enamel organ to become a particular type
of tooth.
FORMATIVE dentin
NUTRITIVE Nourishes the dentin through the odontoblasts & their processes &
by means of the blood vascular system of the pulp.
PROTECTIVE
• Pulp helps in recognition of stimuli like heat ,cold, pressure & chemicals by
way of sensory nerve fibres.
• Vasomotor innervation controls the muscular wall of blood vessels.
• This regulates blood volume & rate of blood flow & hence the intrapulpal Pº.

71. DEFENSIVE
Pulp has remarkable reparative abilities,
It responds to irritation by producing reparative dentin
Mild to moderate irritation results in continued peritubular dentin formation, sclerosis
and intratubular calcifiction-(Tubular sclerosis).
Various cells of the pulp aid in the repair process. The rigid dentinal wall and the
unyielding, enclosure can lead to partial or complete vascular collapse and necrosis of
the pulp.
However, if the inflammation is not too severe, the pulp will heal via its excellent
regenerative properties.

72. PERIPHERAL ZONE
(ODONTOGENIC ZONE).
Zones of the pulp
Dentin
CENTRAL ZONE
(PULP CORE)

73. Odontogenic zone:
(1) odontoblasts:
Location: Adjacent to the predentin with the cell bodies in the
pulp and cell processes in the dentinal tubules.
Dentin

74. (2) Cell free zone (the zone of Weil):
*It is present beneath the odontoblastic layer.
*It is suggested to be the area of mobilization and replacement of
odontoblasts.
(3) cell rich zone:
It is present beneath the cell
free zone.
It is composed of fibroblasts
and undifferentiated
mesenchymal cells.

75. PULP CORE:
• Central Co. T mass.
• Contains blood vessels &
nerves embedded in the pulp
matrix with fibroblasts.
• Neurovascular bundles enter
/exit this core through the
apical foramen.

76. Cells of the pulp
2- Synthetic cells (formative cells):
Odontoblasts and fibroblasts.
Macrophages, lymphocytes, eosinophils, mast
cells and plasma cells.
3- Defensive cells:
1- Progenitor cells:
Undifferentiated mesenchymal cells.

77. 1- PROGENITOR CELLS:
(UMC):
They are smaller than fibroblasts but have a
similar appearance.
They are usually found along the walls of blood
vessels.
These cells have the potentiality of forming
other types of formative or defensive cells.

78. Odontoblasts
In the early stages of development odontoblasts
consist of a single layer of columnar cells .
In the later stages of development, the odontoblasts
appeared pyriform where the broadest part of the cell
contains the nucleus
2-FORMATIVE CELLS:

79. The cell membranes of adjacent odontoblasts
exhibit junctional complexes.
Gap junction
desmosome
coronal pulp- columnar
midportion - cuboidal
apical region–flattened

80. FIBROBLASTS
*These are the most numerous type of pulp
cells.
*They are spindle in shape.
*They have elongated processes which are link up
with those of other pulpal fibroblasts (stellate
appearance.
*The nucleus stains deep with basic dye and
the cytoplasm is highly stained and
homogenous.

81. These cells have a double function: formation and
degradation of fibers and ground substances.
In young pulp, they are :
*Large cells .
*With large multiple processes
*Centrally located oval nucleus,
*Numerous mitochondria,
*Well developed Golgi bodies
*Well developed RER
mitochondria
Fibroblast
protein
secreting cell

82. In periods of less activity and aging they appear
smaller and round or spindle-shaped with few
organelles, they are termed fibrocytes.
fibrocyte
fibroblast

83. DEFENSIVE CELLS:
HISTIOCYTE (MACROPHAGE):
They appear irregular in shape with short blunt
processes.
The nucleus is small, more rounded & darker in
staining than fibroblast.
They are distributed around the odontoblasts and
small blood vessels and capillaries.

84. In case of inflammation:
*Nuclei increase in size and exhibit a
prominent nucleolus.
*It exhibits granules and vacuoles in
their cytoplasm.
Ultastructurally,
invaginations of plasma membrane
with aggregation of vesicles or
phagosomes .

85. *Macrophages are involved in the
elimination of dead cells.
*Macrophages remove bacteria
and interact with other
inflammatory cells to protect the
pulp during inflammation.

86. PLASMA CELLS:
These cells are seen during inflammation.
The nucleus of this cell is small and appears
concentric in the cytoplasm.
The arrangement of chromatin in the nucleus
gives the cell a cart wheel appearance,
The plasma cells are known to produce
antibodies.

87. LYMPHOCYTES
They are found in normal pulp
and they increase during
inflammation.

88. EOSINOPHILS
They are found in normal
pulp and they increase
during inflammation.

89. MAST CELLS:
*They have a round nucleus and their
cytoplasm contains many granules.
*They are demonstrated by using specific
stains as toluidine blue.
*They produce histamine& heparin.

90. Matrix
• COLLAGEN
• ELASTIN
• FIBRONECTIN
• LAMILIN
GAG PR OTEOGLYCAN

91. The ground substances of the pulp:
*The ground substances consists of acid mucopolysaccharides
and neutral glycoprotein.
*These substances are the environment that promotes life of
the cells.
*Glycosaminoglycans are bulky molecules and hydrophilic,
they form gels that fill most of the extracellular space, They
contribute to the high tissue fluid pressure of the pulp.

92. FIBRES
Mainly collagen fibre are type I and type III.
 These fibers form a loose, reticular network to support
other structural elements of the pulp.
 Collagen is synthesized and secreted by odontoblasts and
fibroblasts.
 In young pulp the fibers are relatively sparse throughout
the pulp & gradually the bundles increase in size with
advancing age.

93. Blood vessels
*The pulp is highly vascularized. It is
supplied by the inferior and superior
alveolar arteries & also drain by the same
veins.
*arterioles enter the tooth- direct route to
coronal pulp.
*Along their course they give numerous
branches in the radicular pulp that pass
peripherally to form a plexus in the
odontogenic region.
D

94. Pulp vasculature

95. Nerves of the pulp
The pulp has an abundant nerve supply
which follows the distribution of the
blood vessels.
Two types of nerve fibers are present:
*Sympathetic in nature.
They control the contraction of the smooth
muscles of the blood vessels.
*Sensory nerves.
Both contain myelinated and
unmyelinated axons.

96. A-delta fibers
• Conduction velocity 2-30 m/s
• Lower threshold
• Involved in fast, sharp pain
• Stimulated by hydrodynamic stimuli
• Sensitive to ischemia
C fibers
 Conduction velocity 0-2 m/s
 Higher threshold
 Involved in slow, dull pain
 Stimulated by direct pulp damage
 Sensitive to anesthetics
 Dull pain
Types and properties of pulpal sensory nerve
fibers
A-beta fibers
 Conduction velocity 30-70 m/s
 Very low threshold, non-noxious
sensation
 50% of myelinated fibers in pulp
 Functions not fully known
Non-myelinated sympathetic
fibers
 Conduction velocity 0-2 m/s
 Post-ganglionic fibers of
superior cervical ganglion
 Vasoconstriction

97. *More nerve endings are found in the pulp horns than in other peripheral
areas of the coronal or radicular pulp.
*As the mylelinated nerves run coronally, they give off side branches
and lose their myelin coat & form then sub-odontoblastic plexus of
nerves known as plexus of Rashkow. Few axons extend in-between the
odontoblasts to give the nerve endings.

98. Sensory response in the pulp cannot differentiate
between heat, touch, pressure or chemicals. This is
because the pulp organs lack those types of
receptors.
• Heat,
• Touch,
• Pressure
• Chemicals
Pain

99. Age changes in the pulp
The size of the pulp
The apical foramen
The cellular elements
The bl. vessels & n.
Vitality
.
decreased

100. PATHOGENESIS OF PULP CALCIFICATIONS
LOCAL METABOLIC DYSFUNCTION TRAUMA
HYALINISATION OF INJURED
CELLS
VASCULAR DAMAGE
(thrombosis)
FIBROSIS
MINERALISATION
(nidus formation)
PULP STONES
GROWTH WITH
TIME

101. Types Pulp calcification
localized
(pulp stones )
diffuse
False denticleTrue denticle

102. True denticles
They consist of irregular dentin
containing traces of dentinal tubules
and few odontoblasts.
Remnants of the epithelial root sheath
invade the pulp tissues causing
UMC of the pulp to form this
irregular type of dentin.
• Rare
• Small in size.
• Found near the apical foramen
False denticles
• Evidence of dystrophic calcification of the
pulp tissue .
• No dentinal tubules & can exist in any area of
the pulp.
• Formed of degenerated cells or areas of
hemorrhage which act as a central nidus for
calcification.
• Overdoses of vit. D, may favor the formation
of numerous denticles.

103. Pulp stones are classified according to their location
into: free, attached and embedded.
*They continue to increase in size and in certain cases
they fill up the pulp chamber completely.
*If pulp stones come close enough to a nerve bundle
pain may be elicited.
*The close proximity of pulp stones to blood vessels
may cause atrophy of it.
free
attached

104. Diffuse pulp calcification
*Commonly occurs on top of hyaline
degeneration in the root canal and not common
in the pulp chamber.
*They are irregular calcific deposition in the
pulp tissue following the course of blood
vessels or collagenous bundle.
*Advancing age favors their development.

105. PULP IS A SMALL TISSUE WITH A BIG ISSUE!

106. CLINICAL CONSIDERATIONS:
PULPITIS (PULPAL
INFLAMMATION):
Is a response of the
traumatised pulp,with
trauma being a result of
a bacterial infection as
in dental caries or
physical trauma to the
tooth structure.

107. Pulpitis: Etiology
 Dental caries
 Traumatic
exposure.
 Marginal leakage.
 Cracked tooth
 Coronal fracture.
 Attrition.
 Abrasion.
 Invaginated odontome.
 Advanced periodontitis
(periodontal-
endodontic lesion

108. • Pulp polyp (chronic hyperplastic pulpitis)
-endodontic treatment
-extraction of the tooth

109. CLINICAL SIGNIFICANCE OF APICAL FORAMEN:
 The apical constriction acts as a natural stop for the filling materials.
 Size and shape of the apical foramen should always be maintained.
 It should be neither enlarged nor blocked
 Care should be taken to prevent over instrumentation or extrusion of the root
canal filling materials beyond the apex
LATERAL & ACCESORY CANALS:
Incidence of occurrence of lateral & accessory canals is high in human teeth, but
the percentage of failures due to unfilled lateral canals is less.
This is probably because of biological hard (dentin & cementum) tissue closure
of lateral assessory foramina .

110. • Shape of the pulp chamber & its extensions into the cusps, pulpal horns is
important.
• Wide pulp chamber in tooth of young person will make a deep cavity
preparation hazardous.
• The pulpal horns project high into the cusps in younger ages exposure of
pulp can occur
• If opening a pulp chamber for treatment, its size and variation in shape
must be taken into consideration.
With advancing age,
• pulp chamber becomes smaller,
• Pulp stones at the opening of root canal
• In anterior teeth coronal part of pulp chamber may be filled with secondary
dentin.
• When the apical opening is at the side of the apex, not even radiographs
will reveal true length of RC
• Difficult to locate root canals
DURING OPERATIVE PROCEDURES

111. IMMEDIATE PULP EXPOSURE TO A HEALTHY TOOTH
PORTIONS OF ODONTOBLASTIC LAYER,CELL FREE, CELL RICH LAYER
& PULP PROPER ARE DESTROYED.
BLOOD VESSELS & NERVE ARE CUT
EXTRAVASATED RBCS & PLASMA CAUSES TISSUE EDEMA
INCREASED INTERSTITIAL PRESSURE IN THE SURROUNDING PULPAL
TISSUE
AFTER 2 DAYS OF PULP CAPPING WITH CAOH
EXPOSURE SITE CONTAINS A CLOT
CLOT BECOMES REORGANIZED
BY 5 DAYS, CLOT BECOMES PHAGOCYTOSED
NEOANGIOGENESIS & FIBROBLASTS FORMS GRANULATION TISSUE
FIBROBLASTS BECOME PARALLEL TO MEDICAMENT INTERFACE
7-9 DAYS, FIBROBLASTS ENLARGE , NOW THESE ODONTOBLAST LIKE
CELLS ORIENT PERPENDICULAR TO THE PULP CAPPING MATERIAL
BY 12 DAYS, REPAIRATIVE DENTIN IS FORMED.

112. HEALING AFTER CAVITY PREPARATION:
CAVITY PREPARATION
INJURES ODONTOBLASTS & OPENS D.TUBULES & DISPLACES NERVE &
NERVE TERMINALS NEAR TO THE ODONTOBLASTS & ODONTOBLASTIC
PROCESSES
RAPID RELEASE OF NEUROPEPTIDES(SUBSTANCE P) IN THE VESICLES OF
N.TERMINALS
INFLAMMATORY CELLS RECRUITED TO THAT AREA, CELL RELEASE
HISTAMINE, SEROTONIN & PROSTAGLANDINS
JUNCTIONAL COMPLEX DISRUPTION ALLOW CA IONS INFLUX FROM
DENTINAL FLUID INTO THE INJURED ODONTOBLAST
INTRACELLULAR SPACES BECOME FILLED WITH FLUIDS & PROTEINS FROM
PLASMA LEAKING FROM THE CAPILLARIES
CLOTTING CASCADE INITIATED PREVENTS FURTHER INGRESS OF
IRRITANTS TO THE DENTAL PULP

113. WITHIN ONE DAY, A SHALLOW CAVITY PREPARATION, ODONTOBLASTS
REORGANISE & REESTABLISH THEIR PLASMA MEMBRANES
THESES ODONTOBLASTS BEGIN TO SECREATE COLLAGEN & ECM
COMPONENT
AT 5 DAYS, GAP JUNCTIONS& TIGHT JUNCTIONS RESTABLISH
BY 14 DAYS, INFLAMMATORY RESPONSE IS RESOLVED, ODONTOBLASTS
CELL LAYER IS REESTABLISHED

114. PULPAL REACTION TO LASER
PROCEDURE
Laser use on soft / hard tissues has potential
benefits of efficiency, reduced sensitivity,
disinfection and precision.
PULPAL REACTION TO
ORTHOGNATHIC SURGERY
Osteotomy of the jaw → Disruption in the
blood supply
Studies have shown that if a safe distance
of 5 to 10 mm is maintained between the
site of the surgery and the teeth, minimal
disruption occurs. In most cases, the blood
flow is regained within months of the
surgery.

115. Orthodontic forces:
pulpal cell damage, inflammation, vasodilatation.
• Orthodontic forces should be light and continuous, respecting
physiologic boundaries.
• Care should be taken to ensure that the intended orthodontic tooth
movement does not challenge the apical blood supply (e.g.
compressing the root apex against the cortical plate).
• Pulpal symptoms that arise during orthodontic treatment should be
treated appropriately and swiftly.

116. References:
• B.K. B Berkovitz oral anatomy, histology and embryology, Fourth edition
• Ten cates , Oral histology , Eighth edition
• Orbans , oral histology and embryology , 13th edition
• Shafers , textbook of oral pathology , seventh edition
• Oral development and histology , James K Avery, Third edition
• Textbook of endodontics, Nisha garg second edition
• Autogenous fresh demineralized tooth graft
prepared at chairside for dental implant - Eun-Seok Kim
Kim Maxillofacial Plastic and Reconstructive Surgery (2015) 37:8
DOI 10.1186/s40902-015-0009-1

117. • caries Res.2006;40(3):256-64.
Dentin-pulp complex responses to carious lesions.
Lee YL, Liu J, Clarkson BH, Lin CP, Godovikova V, Ritchie HH
• The dental pulp -Seltzer’s 3rd edition
• Endodontics : Priciples and practices Torabine jad, Richard E 4TH edition.
• Analysis of the inorganic component of autogenous tooth graft material
Young kyun Kim, su gwan Kim & co workers
journal of nanoscience and nanotechnology
vol. 11, 7442-7445, 2011
• Clinical application of auto-tooth bone graft
Sung- min park & co workers
J Korean Assoc `Oral Maxillofac Surg 2012;38:2-8.
• A longitudinal study of tooth growth in a single individual based on long & short
period incremental markings in dentine & enamel.
M. C. Dean & co workers
International journal of osteoarcheology, vol 3: 249- 264(1993)

118. • Extent of aspartic acid racemization in dentin: a possible marker for a more
accurate determination of age at death.
S. Ritz & co workers
Z Rechtsmedizin(1990) 103; 457-462.