The document describes the structural components of dental pulp, detailing cellular elements such as odontoblasts, fibroblasts, undifferentiated mesenchymal cells, and immunocompetent cells, along with their functions. It discusses the extracellular components, including fibers, ground substance, blood vessels, lymphatic channels, and nerve supply, highlighting their roles and changes with age. The organization and functions of these components contribute to the integrity and health of dental pulp.

1. PULP
STRUCTURAL COMPONENTS OF DENTAL PULP

2. 
CELLULAR EXTRACELLULAR CONNECTIVETISSUE
1.ODONTOBLASTS 1.COLLAGEN FIBERS 1.BLOOD VESSELS
2. FIBROBLASTS 2.INTERCELLULAR GS 2.LYMPHATIC CHANNELS
3.UNDIFFERENTIATED 3.NERVE FIBERS
MESENCHYMAL CELLS
4.IMMUNOCOMPETENT
CELLS

3. CELLS OF PULP
1. ODONTOBLASTS :
• Ectomesenchymal origin-Dentin forming cells
• Second most prominent cells of pulp
• Location: adjacent to dentin (cell bodies-pulp, cell
processes-dentinal tubules)
• Large in coronal pulp and comparatively smaller in
radicular pulp
• Morphological variations – tall columnar in crown, low
columnar in mid of root , flat near apex

4. • Shape of the cells depends upon degree of activity
• More active cells – tall, oval nucleus at pulpal end and abundant
cytoplasmic organelles
• The cell becomes narrower at apical end and enters predentin –
odontoblastic processes
• Odontoblastic processes are devoid of organelles but contain
microtubules, filaments and vesicles
• Junctions like gap ,tight , desmosomes are seen
• Based on activity odontoblastscan be classified into
1) Synthetic(active odontoblasts)
2) Intermediate(transitional odontoblasts)
3) Resting(aged odontoblasts)

5. TYPES OF ODONTOBLASTS IN PULP
1) ACTIVE
• Elongated cells,basal
nucleus & basophilic
cytoplasm
• Abundant synthetic
cellular organelles (for
secretion of dentin
matrix)
• Abundant secretory
granules
2) TRANSITIONAL
• Similar features as
that of active
odontoblasts
• Comparatively
organelles are lesser
and less prominent
• Less secretory
granules
• Condensed
chromatin with
organelles
distributed around
the nucleus
3) AGED
• Little cytoplasm
• Dark and close
faced
nucleus(transcriptio
nally inactive
nucleus)
• Less organelles
• Secretory granules
and vacuolesare
rare/absent

7. 2. FIBROBLASTS :
▪ Most numerous cells of pulp
▪ Variable shape-fusiform, stellate
▪ Numerous in younger teeth and decreases with age
▪ Function – synthesis , maintenance and degradation of
pulp matrix

9. 3. Undifferentiated mesenchymal cells:
o Polyhedral in shape with peripheral processes and a large central
nucleus
o Found in cell rich zone and are scattered throughout the central pulp
o Reserve cells - CT cells of pulp are derivedfrom these cells
o Show totipotency ( can give rise to different cells like odontoblasts,
fibroblasts)
o More in younger pulp
o Decreases withage thus reducing the regenerative powerof pulp

10. 4. IMMUNOCOMPETENT CELLS :
MACROPHAGES
o Found in central part
of pulp
o Large oval/spindle
shaped
o RER , mitochondria,
free ribosomes are
found
o Round and densely
stained nucleus
o Function – scavenger
cells ( eliminate dead
cells)
DENDRITIC CELLS
o Antigen presenting
cells
o Dendritic processes
extend between the
odontoblasts
o Non phagocytotic
cells
o Function-Participate
in cellular immunity
by presenting
antigens to T-cells
o Increase during
dental caries
LYMPHOCYTES &
EOSINOPHILLS
o Number increases
during
inflammation

12. EXTRACELLULAR COMPONENTS :
1.FIBERS
o Collagen type-I and type-III
o Exhibit cross striations
o In younger pulp fibrils are of smaller
diameter and these aggregate in
older pulp to form thicker fibers
o Scattered fibers – diffusedcollagen
o Bundled fibers – bundle collagen
o Few reticular fibers and elasticfibers
may be present
2.GROUND SUBSTANCE
o Composedof
mucopolysaccharides and protein
polysaccharide complex( GAG’S
and proteoglycans )
o Functions :
1. Medium for distribution of cells and
fibers
2. Support to cells
3. Medium for transport of nutrients
and catabolites
o It decreases with age

13. Connective tissue components:
a) BLOOD VESSELS
o Highly vascularized – supplied by sup and inf alveolararteries
o Blood vesselsenter through apical and accessory foramen
o In coronal pulp they undergo extensive branching
o In peripheral pulp they form sub odontoblastic capillary network
o Arterioles divide into – meta arterioles, pre capillaries and capillaries
o Capillariesshow fenestrations for exchange of materials
o Venous drainage of pulp is by same veins

14. b) LYMPHATIC CHANNELS :
o Lymph vessels in pulp are thin walled and irregular lumen composed of
endothelial cells surrounded by an incomplete layer of smooth muscles
o Anterior teeth drains into- submental lymph nodes
o Posterior teeth drains into – sub mandibular lymph nodes and deep cervical
lymph nodes
c) Nerve supply :
o The nerve bundles that enter pulp consist principally of :
 Sensory afferent nerves of the TRIGEMINAL NERVE
 Sympathetic branches from the SUPERIOR CERVICAL GANGLION
The nerve fibers in pulp are non myelinated :
 A DELTA AND A BETA – TRANSMIT SHARP PAIN
 C FIBERS TRANSMIT DULL PAIN

15. PLEXUS OF RASCHKOW:
 PLEXUS OF NERVE FIBERS THAT ARE FORMED DUE TO
BRANCHING AND REBRANCHING OF MYLIENATED NERVE
FIBERS LOCATED IN CELL RICH ZONE OF PULP