2. Pulp
Mesenchyme connective tissue
that occupies pulp cavity in the
central part of the teeth
Surrounded by dentin on all sides
except at the apical foramen &
accessory canal openings
3. There are a total of 32 pulp
cavities in the adult dentition.
The pulp cavities of molar teeth
are approximately four times
larger than those of incisors.
The pulp cavity extends down
through the root of the tooth as
the root canal which opens into
the periodontium via the apical
foramen.
The blood vessels, nerves etc. of
dental pulp enter and leave the
tooth through this foramen.
Pulp
Cavity
6. Pulp
32 (permanent) + 20 (primary) =
52 Pulp organs
Total volumes of perm. teeth pulp organs =
0.38 cc
Mean volume of a single adult human pulp =
0.02 cc
Molar pulps are 3-4 times larger than
incisor pulps
7. DEVELOPMENT
Formed by dental papilla.
Odontoblasts – neural crest origin (ectodermal).
Other pulpal cells - mesenchymal origin.
Immature dendritic cells appear in and around the
odontoblastic layer at early stage.
First layer of dentin deposited- dental papilla
becomes dental pulp.
Numerous fibroblasts-remain closely packed, are
stellate shaped with large nucleus and little
cytoplasm and lay down fine collagen fibres.
8. DEVELOPMENT
Developing pulp has high GAG content.
Chondroitin sulphate is higher with little hyaluronan,
while opposite is true for mature pulp.
Enamel organ extends as HERS and determines final
morphology of the space (pulp chamber and root canals).
Once full length of roots is established, the developmental
stage of dental pulp can be considered complete.
10. Coronal pulp
Has pulp horns which are protrusions
that extend into the cusps of each crown
Number depends on the cuspal number
Pulp becomes smaller with age
11.
12. Radicular pulp
Extends from the cervical region of the
crown to the root apex
Anterior teeth-single
Posterior teeth-multiple
Continuous with the periapical
connective tissues through the
apical foramen
15. • The peripheral aspect of dental pulp, referred to as the
odontogenic zone , differentiates into a layer of dentin-
forming odontoblasts .
•Immediately subjacent to the odontoblast layer is the
cell-free zone (of Weil). The cell-free zone of Weil is also
called “sub-odontoblastic layer” or “Hoehl's layer.”
•This region contains numerous bundles of reticular
(Korff's) fibers . These fibers pass from the central pulp
region, across the cell-free zone and between the
odontoblasts, their distal ends incorporated into the
matrix of the dentin layer. Numerous capillaries and
nerves are also found in this zone.
•
16. Just under the cell-free zone is the cell-rich zone
containing numerous fibroblasts the predominant cell
type of pulp. Fibroblasts of the pulp have demonstrated
the ability to degrade collagen as well as form it.
The pulp core zone comprises prominent blood vessels
and nerves and is present below the cell rich zone.
19. Odontoblasts:
Second most prominent cells of pulp
palisade pattern of arrangement in the
crown of the mature tooth
Constant location adjacent to the
predentin-odontogenic zone of the
pulp
Cell body in pulp & cell processes in the
dentinal tubules
Tall columnar in crown, cuboidal in
middle of root & flat spindle shaped near
the apex of tooth
24. Odontoblasts:
Undergo apoptotic cell death –shown by
marker bcl-2
Release interleukin -8
Nitric oxide synthetase have been
identified in odontoblasts
25. Fibroblasts:
Cells occurring in greatest numbers
in the pulp
More in number in the coronal
portion of pulp where they form the
cell-rich zone
Form &maintain the pulp matrix,
which consists of collagen & ground
substance
26. Fibroblasts:
They function in collagen fiber
formation
In young pulp the cells divide & are
active in protein synthesis
In older pulp they appear rounded
or spindle shaped with short
processes & exhibit fewer
intracellular organelles –fibrocytes
27. Fibroblasts:
Immature pulp - cellular elements
predominate
Mature pulp - fibrous components
predominate
Dual function; In addition to
forming the pulp matrix, capable of
ingesting °rading the same
matrix
28. Fibroblasts….
Secrete angiogenic factors like FGF-2
& VEGF
Secrete colony stimulating factor
In cell culture on stimulation form
mineralized tissue
29.
30. Macrophages
Oval or spindle shaped
Macrophages are present in the normal
dental pulp & are more dense around the
blood vessels of the inner pulp & around
the odontoblast layer
31. Dendritic cells:
Bone marrow- derived, antigen
presenting dendrite cells are found
in & around the odontoblast layer in
nonerupted teeth & in erupted teeth
beneath the odontoblast layer
Function is similar to Langerhans
cells in that they capture & present
foreign antigen to the T cells
32. Dendritic cells:
Participate in immunosurveillance
& increase in number in carious
teeth
Dendritic cells & macrophages
constitute some 8% of the total
cell population, with dendritic
cells exceeding macrophages
33. Undifferentiated
ectomesenchymal cells
Totipotent cell
Depending upon the stimulus these
cells may give rise to odontoblasts ,
fibroblasts or macrophages.
Represent the pool from which
connective tissue cells of the pulp are
derived
34. Matrix & ground substance
Collagen-typeI & typeIII
Ground substance composed of
glycosaminoglycans, glycoproteins & water
Ground substance lend support to the cells of
the pulp& also serve as transport medium of
nutrients from the blood vessels to the cells &
transport of metabolites from cells to blood
vessels
35. Pulpal stem cells
Migrate to the site of injured
odontoblasts & produce dentin
TGF beta 1 & BMP-2 involved in the
migration of stem cells
Pluripotent-adipocytes & neural cells
36. Pulpal stem cells
Produce dentinogenesis &
osteogenesis
Dentin sialoprotein present
Dentonin stimulate dental pulp stem
cell
Pulp tisue of 3rd molars - viable after
cryopreservation
37. Functions of pulp
1. Inductive: interact with oral
epithelial cells leading to
differentiation of dental lamina &
enamel organ formation
2. Formative: formation of dentin
3. Sensory: sensation of tooth is felt
through the nerves of the pulp
38. Functions of pulp
4. Nutritive: supplies nutrition to the
dentin through blood vessels &
odontoblastic processes & maintain the
vitality of tooth
5. Defensive or reparative: protects it
self & vitality of the tooth by producing
reparative dentin
39. Blood vessels of the dental pulp:
Supply oxygen & nutrients where they are
most needed during dentinogenesis
Pulpal blood flow-
1.in arterioles-0.3to1mm/sec
2.In venules-approx.0.15mm/sec
3.In capillaries-approx.0.08mm/sec
Arise from inferior or superior alveolar
artery
40. Blood vessels of the dental pulp:
Pericyte lies on the surface of vessels
Arterio-venous shunts regulate blood flow
Blood capillaries – 8-10microm in
diameter
Fenestrated capillaries-rapid transport of
metabolites during dentinogenesis
41.
42.
43. Nerves of the dental pulp
Nerves enter pulp through apical
foramen, along with afferent blood
vessels & together form the “neuro-
vascular bundle”
Nerve bundles that enter the pulp
consists principally of sensory afferents of
the trigeminal nerve & sympathetic
branches from the superior cervical
ganglion
44. Nerves of the dental pulp
In the crown there is a pronounced
plexus of nerves beneath the
odontoblasts, known as the plexus of
Raschkow – occupy the cell-
free zone of weil & can be demonstrated
in silver stained sections under light
microscope or by immunocytochemical
techniques
In the root-no corresponding plexus
48. Regressive changes (aging)
Fibrosis
• Accumulation of both diffuse fibrillar
components & bundles of collagen
fibers
• External trauma such as dental caries or
deep restorations causes localized
fibrosis or scarring effect
• Atherosclerotic plaques may appear in
pulpal vessels
• Calcifications are found that surround
vessels
49. Regressive changes (aging)
Pulp stones (denticles):
• Nodular, calcified masses appearing in
either or both the coronal & root
portions of the pulp organ
• Asymptomatic, unless they impinge on
nerves or blood vessels
• Seen in functional as well as embedded
unerupted teeth
52. Pulp stones:
True denticles:
• Similar in structure to dentin
• Are rare, located close to the apical foramen
• Development is caused by the inclusion of
remnants of the epithelial root sheath within
the pulp
• These epithelial remnants induce the cells of
the pulp to differentiate into odontoblasts,
which then form the dentin masses called
true pulp stones
53. Pulp stones:
False denticles:
• Do not exhibit dentinal tubules
• Concentric layers of calcified tissue
• Some cases calcification sites appear
within a bundle of collagen fibers
• Phleboliths-serve as nidi for false
denticles
• All denticles begin as small nodules
but increase in size by incremental
growth on their surface
57. Pulp stones:
Free denticles:
entirely surrounded by pulp tissue
Attached denticles:
partly fused with the dentin
Embedded denticles:
entirely surrounded by dentin
58. Pulp stones:
Incidence –
66%of teeth-10-3oyears
80% of teeth-30 & 50 years
90%-over 50 years of ageFree
denticles:
59. Diffuse calcifications
Irregular calcified deposits
following collagen fibre bundles or
blood vessels
Found more in the root canal &
less in coronal area
Surround blood vessels-dystrophic
calcification
61. Clinical considerations:
Wide pulp chamber in the tooth of a
young person will make a deep cavity
preparation hazardous
Dehydration cause pulpal damage
Associated with trauma, the pulp
becomes transformed into granulation
tissue and the dentine commences to be
resorbed internally at the pulp-dentine
surface
62. Diseases of dental pulp
Etiology –
1. Dental caries
2. Tooth fracture – trauma
cracked tooth syndrome
3. Anachorectic pulpitis
- anachoresis – phenomenon by which blood borne
bacteria, dyes, pigments, metallic substances, foreign
products & other materials are attracted towards the
site of inflammation
- probable cause – increased capillary permeability in
particular area
