The dental pulp is a soft connective tissue located within the tooth. It supports the dentin and provides nutrition for tooth development. The pulp is divided into the coronal pulp in the crown and the radicular pulp in the roots. The coronal pulp contains pulp horns that extend into tooth cusps while the radicular pulp tapers toward the apical foramen. The pulp contains cells like odontoblasts, fibroblasts, and immune cells and has functions like tooth development, nutrition, sensation, repair, and defense against pathogens. Changes with aging include decreased cell size and number as well as increased fibrosis and calcification. Clinical considerations for the pulp include its shape, size changes with age, and the effects of

1. DENTAL PULP
DR.AMANI MAHAJAN
MDS ORAL PATHOLOGY
& MICROBIOLOGY
DR.AMANI MAHAJAN

2. INTRODUCTION
• Pulp is a soft
mesenchymal connective
issue that occupies pulp
cavity in the central part
of the teeth
• It supports the dentin and
is unique because of its
unique environment.
• initially it was dental
papilla with increased
amount of capillaries
which provide nutrition
during amelogenesis and
dentinogenesis.
DR.AMANI MAHAJAN

3. Total of 52 pulp organs: 32 in the permanent
and 20 in the primary teeth.
Total pulp volume in permanent teeth is
0.38cc with mean being 0.02CC
Each of these organs has a shape that
conforms to that of the respective tooth.
DR.AMANI MAHAJAN

4. The pulp cavity is divided into
1. Coronal pulp
2. Radicular pulp
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5. It is located centrally in the crowns.
It has six surfaces: occlusal, mesial, distal, buccal,
lingual and floor.
It has pulp horns, which are protrusions that extend into the cusps of
each tooth. The number of these pulp horns thus depends upon the
number of cusps.
 The cervical region of the pulp organs constricts as does the contour
of the crown. At this point coronal pulp joins with the radicular pulp.
Coronal pulp
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6. It is present in the roots.
It extends from the cervical region to the root apex.
They are not always straight and vary in size, shape and number.
The dentinal wall taper and shape of the radicular pulp is tubular.
During root formation the root end is wide opening limited by an
epithelial diaphragm.
As growth proceeds, more dentin is formed so that as the tooth
matures, the radicular pulp is narrower.
Apical pulp canal becomes smaller also because of apical
cementum deposition.
Radicular pulp
DR.AMANI MAHAJAN

7. The average size of apical foramen in maxillary teeth in adults is
0.4mm.
In mandibular teeth , it is about 0.3mm .
The location and shape of the apical foramen may undergo changes
as a result of functional influences on the teeth.
Tooth may be tipped from horizontal pressure or it may migrate
mesially. Under such conditions tissue entering pulp through the
apical foramen may exert pressure on the wall of the foramen
causing resorption.
APICAL FORAMEN
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8. At the same time cementum is laid down on the opposite
side of the apical root canal resulting in relocation of the
apical foramen.
Sometimes apical foramen may be found on the lateral side
of the apex although the root itself is not curved.
There may be presence of two or more foramina separated
by a portion of dentin and cementum or only by cementum
DR.AMANI MAHAJAN

9. From the radicular pulp they run laterally through the root dentin
to the PDL tissue. They occur in areas where
• there is premature loss of root sheath cells
• Where the developing root encounters a blood vessel.
They act as a route for transmission of infection from the pulpal
tissue to periodontal tissues and vice a versa .Branching pattern of
the small accessory canals and minor foramina seen at the tip or
apex of some tooth roots form the apical delta
ACCESSORY CANALS
DR.AMANI MAHAJAN

10. STRUCTURALORGANIZATION OF PULP
Central region of both radicular and
coronal pulp contains large nerve
trunks and blood vessels.
Peripherally, the pulp is
circumscribed by specialized
odontogenic region composed of:
1. Odontoblasts
2. The cell free zone (of Weil’s)
3. The cell rich zone and
4. The pulp core which is
characterized by major vessels
and nerves
DR.AMANI MAHAJAN

11. ODONTOBLAST LAYER
A layer of odontoblasts are found along
the pulp periphery.
They are dentin forming cells.
DR.AMANI MAHAJAN

12. Immediately subjacent to odontoblastic zone in coronal
pulp there is a narrow zone, approximately 40µm in
width that is relatively free of cells and hence called Cell
free zone of Weils.
 It is traversed by blood vessels, unmyelinated nerve
fibers and slender cytoplasmic processes of fibroblasts. It
may not be apparent in young pulp where dentin forms
rapidly or in older pulps where reparative dentin is being
produced.
Cell free zone
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13. Below cell free zone a layer containing relatively high
proportions of fibroblasts compared with more central
region of pulp.
it is more prominent in coronal pulp than in radicular
pulp.
It also include large number of macrophages, dendritic
cells and undifferentiated mesenchymal cells.
CELL RICH ZONE
DR.AMANI MAHAJAN

14. The pulp proper is the central mass of pulp.it contains
the large vessels and nerves.
 The connective tissue cells in this zone consist of
fibroblasts or pulpal cells
Pulp proper
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15. CELLS OF PULP
Fibroblasts
Undifferentiated Cells
Odontoblasts
Defense Cells
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16. FIBROBLASTS
Fibroblasts are the most numerous cells in the pulp.
They form the collagen fibers, through out the pulp during the life
of the tooth.
The fibroblasts are stellate shaped cells having extensive processes
that contact and are joined by intercellular junctions to the processes
of other fibroblast
DR.AMANI MAHAJAN

17. Young pulp - Fibroblasts have abudant
cytoplasm having numerous cell
organells.
Older pulp - Fibroblasts appear round
or spindle shaped posses short
processes having few cytoplasmic
organelles such cells are called
fibrocytes
DR.AMANI MAHAJAN

18. Dual function :
a) It has capability of ingesting and
degrading the organic matrix.
b) Pathway of both synthesis and degreadation
in the same cell.
DR.AMANI MAHAJAN

19. Primary cells in the very young pulp.
They are polyhedral in shape with peripheral
processes and a large oval nuclei.
They are Totipotent cells i.e. when the need arises
they can be converted into macrophages, odontoblast,
fibroblast etc.
UNDIFFERENTIATED MESENCHYMAL CELLS
DR.AMANI MAHAJAN

20.  macrophages, dendritic cells, plasma cells, mast cells, neutrophils,
eosinophils, basophils, lymphocytes, monocytes are present in the
pulp.
Macrophages are Irregularly shaped cell with short blunt processes.
Macrophages appear as large oval or sometimes elongated cells that
exhibit a dark-stained nucleus.
They act as scavengers ,removing extravasated red blood cells, dead
cells and foreign bodies from the tissue. Ingested material is destroyed
by lysosomes.
DEFENSE CELLS
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21. Dendritic cells are Antigen-presenting cells. These cells
participate in immunosurveillance and increase in number in
carious teeth, where they infiltrate the odontoblast layer
Plasma cells function in the production of antibodies
Mast cells are widely distributed. Seldom found in normal pulp
tissue although they are routinely found in inflamed pulp
DR.AMANI MAHAJAN

22. ODONTOBLASTS
2nd most prominent cells in the pulp.
A Peripheral area of the pulp where the
odontoblasts reside is termed odontogenic
zone.
Arranged in Palisading pattern cells are tall
columnar forming a layer of 3 to 5 cells in
depth.
Shape may vary
cornal pulp- columnar
midportion - cuboidal
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23. These cells have large process extending into
Dentin.
Odontoblasts in the crown are larger than in the
root.
DR.AMANI MAHAJAN

24. Shape of the odontoblasts also reflect the functional
activity of the cell.
During active phase, cells show increase in endoplasmic
reticulum golgi appartus and secretory vesicles.
Resting (or) Non active phase cells are flattened little
cytoplasm condensed chromatin and decrease no of ER
DR.AMANI MAHAJAN

25. EXTRACELLULAR MATRIX
Connective tissue fibers
Collagen
Elastin
Fibronectin
Ground substance
Proteoglycans
Glycosaminoglycans
Basement membrane
DR.AMANI MAHAJAN

26. INDUCTIVE
FORMATIVE
NUTRITIVE
PROTECTIVE
REPARATIVE
FUNCTIONS OF DENTAL PULP
DR.AMANI MAHAJAN

27. INDUCTIVE: Induces oral epithelial differentiation into dental lamina &
enamel organ. Interacts with Enamel organ and determines tooth
morphology
FORMATIVE: pulpal odontoblasts produce dentin which surrounds &
protects it
NUTRITIVE: nourishes dentin through odontoblast by means of blood
vascular system of pulp
PROTECTIVE: when any stimuli like heat, cold, pressure, chemicals is
applied nerves in pulp gets stimulated and produce pain
DEFENSE OR REPARATIVE: responds to irritation by producing
reparative dentin and mineralizing any affected dentinal tubules.
DR.AMANI MAHAJAN

28. REGRESSIVE CHANGES (AGING)
1)CELL CHANGES: The cells are characterized by a decrease in
size and a number of cytoplasmic organelles.
2) FIBROSIS: There is increase in fibers.
3)VASCULAR CHANGES: Atherosclerotic plaques may appear in
pulpal vessels. Calcifications may be seen. Blood flow decreases
with age
4) PULP STONES
DR.AMANI MAHAJAN

29. PULP STONES
Pulp stones are nodular, calcified masses appearing in either or both
the coronal or root portion of the pulp organ.
TRUE DENTICLES
FALSE DENTICLE
DIFFUSE CALCIFICATION
DR.AMANI MAHAJAN

30. TRUE DENTICLES-Structure similar to dentin. Comparatively
rare and usually located close to the apical foramen. Development
is due to inclusion of remnants of epithelial root sheath within the
pulp
FALSE DENTICLES-Do not exhibit dentinal tubules but appear
as concentric layers of calcified tissue
DIFFUSE CALCIFICATIONS-Appear as irregular calcific
deposits in the pulp tissue, usually following collagenous fiber
bundles or blood vessels. Usually found in root canal and less
often in coronal area
DR.AMANI MAHAJAN

31. Pulp stones are also classified according to their location in relation
to the surrounding dentinal wall:
1.Free denticles –present in the pulp
2.Attached denticles-present in between pulp and dentin
3.Embedded denticles-present in the dentin
DR.AMANI MAHAJAN

32. CLINICAL CONSIDERATIONS
Shape of the pulp chamber and its extensions into the
cusps pulpal horns is important.The pulpal horns project
high into the cusps exposure of pulp can occur.
With the advancing age the size of pulp chamber
decreases whereas in young age pulp horns are wider &
high.
Cavity preparation: speed, heat, pressure & coolant may
all cause pulp irritation.
Thickness & nature of remaining dentine may affect pulp
response to dental material. Remaining dentin thickness:
2 mm.
DR.AMANI MAHAJAN

33. CLINICAL CONSIDERATIONS
Shape of the apical foramen and its location may play an
important part in treatment of root canals. Accessory canals
& multiple canals are rarely seen in IOPA.
Irreversible changes occur at temperatures higher than 45
degrees centigrade. It has been noticed that at a
temperature lower than -2 degrees centigrade the pulpal
necrosis can occur.
DR.AMANI MAHAJAN

34. DR.AMANI MAHAJAN