Dental Pulp

DENTAL PULP
11
Dr. Madhu Billa
I MDS
DEPT OF CONSERVATIVE DENTISTRY AND ENDODONTICS
SIBAR INSTITUTE OF DENTAL SCIENCES
Dr.MadhuBillaDr.MadhuBilla

CONTENTSCONTENTS
Introduction
Anatomy
Structural organization of pulp
Cells of pulp
Extra-cellular matrix
Circulation & Innervation of pulp
Functions of pulp
Pulp calcification
Age changes
Clinical significanceDr.MadhuBillaDr.MadhuBilla 22

INTRODUCTIONINTRODUCTION
The Pulp is a soft mesenchymal connectiveThe Pulp is a soft mesenchymal connective
tissue that occupies pulp cavity in the centraltissue that occupies pulp cavity in the central
part of the teeth.part of the teeth.
It is a special organ because of its uniqueIt is a special organ because of its unique
environmentenvironment
Dr.MadhuBillaDr.MadhuBilla 33

FEATURES OF PULPFEATURES OF PULP
Enclosed within dentinEnclosed within dentin
Resembles embryonic connective tissueResembles embryonic connective tissue
Microcirculatory system with no collateralMicrocirculatory system with no collateral
systemsystem
Retains ability to form dentin throughout lifeRetains ability to form dentin throughout life

ANATOMY OF PULPANATOMY OF PULP
52 pulp organs – 32 + 2052 pulp organs – 32 + 20
Total pulp volume in permanent teeth is 0.38Total pulp volume in permanent teeth is 0.38
cc. with mean being 0.02 cc.cc. with mean being 0.02 cc.
The pulp cavity is divided into coronal pulpThe pulp cavity is divided into coronal pulp
and radicular pulpand radicular pulp

CORONAL PULPCORONAL PULP
It is the pulp occupying the pulp chamber ofIt is the pulp occupying the pulp chamber of
the crown of the tooththe crown of the tooth
In young teeth it resembles the shape of theIn young teeth it resembles the shape of the
outer dentinouter dentin
It has six surfaces: occlusal, mesial, distal,It has six surfaces: occlusal, mesial, distal,
buccal, lingual and floorbuccal, lingual and floor
Pulp horns are projections into the cuspPulp horns are projections into the cusp
This pulp constricts at the cervical regionThis pulp constricts at the cervical region
where it continues as the radicular pulpwhere it continues as the radicular pulp

RADICULAR PULPRADICULAR PULP
It is the pulp occupying the pulp canals of theIt is the pulp occupying the pulp canals of the
root of the toothroot of the tooth
In the anterior tooth it is single and in theIn the anterior tooth it is single and in the
posterior teeth it is multipleposterior teeth it is multiple
It is more fibrous & whitish color, whichIt is more fibrous & whitish color, which
protects the neurovascular bundleprotects the neurovascular bundle
As age advances the width of the radicularAs age advances the width of the radicular
pulp is reduced, and so is the apical foramenpulp is reduced, and so is the apical foramenDr.MadhuBillaDr.MadhuBilla 77

APICAL FORAMENAPICAL FORAMEN
It forms the portal of entry or exit for theIt forms the portal of entry or exit for the
contents of the pulpcontents of the pulp
Mean size:Mean size:
Maxillary teeth – 0.4 mmMaxillary teeth – 0.4 mm
Mandibular teeth – 0.3 mmMandibular teeth – 0.3 mm
Migration or horizontal pressure causes theMigration or horizontal pressure causes the
apex to tilt, changing the position of the apicalapex to tilt, changing the position of the apical
foramenforamen Dr.MadhuBillaDr.MadhuBilla 88

There may be 2-3 foramina separated byThere may be 2-3 foramina separated by
cementum or dentin- APICAL DELTA.cementum or dentin- APICAL DELTA.
Largest in palatal root of maxillary teeth andLargest in palatal root of maxillary teeth and
distal root of mandibular teeth.distal root of mandibular teeth.
It is usually 0.5-0.75 mmIt is usually 0.5-0.75 mm
occlusal to the anatomic apex.occlusal to the anatomic apex.

ACCESSORY CANALACCESSORY CANAL
Leading laterally from the radicular pulp intoLeading laterally from the radicular pulp into
the periodontal tissue.the periodontal tissue.
Present in the apical third of the root.Present in the apical third of the root.
Formed due to premature loss of HERS orFormed due to premature loss of HERS or
when developing root encounters a bloodwhen developing root encounters a blood
vessel.vessel.
May also be present at the furcation region.May also be present at the furcation region.Dr.MadhuBillaDr.MadhuBilla 1010

ACCESSORY CANALSACCESSORY CANALS

CANAL CONFIGURATIONCANAL CONFIGURATION
by Weine in 1982by Weine in 1982

VERTUCCI CLASSIFICATIONVERTUCCI CLASSIFICATION

DEVELOPMENTDEVELOPMENT
The primitive oral cavity orThe primitive oral cavity or
stomodeum, is lined by astomodeum, is lined by a
stratified squamous epitheliumstratified squamous epithelium
called ascalled as oral ectodermoral ectoderm..
During 6th week of theDuring 6th week of the
intrauterine life or two to threeintrauterine life or two to three
weeks after the rupture of theweeks after the rupture of the
buccopharyngeal membrane,buccopharyngeal membrane,
basal cells of the oral ectodermbasal cells of the oral ectoderm
in certain areas proliferate fasterin certain areas proliferate faster
than the adjacent cells and formsthan the adjacent cells and forms
dental laminadental lamina..
Bud stageBud stage
1414Dr.MadhuBillaDr.MadhuBilla

Early cap stage;Early cap stage;
Certain areas along theCertain areas along the
dental lamina,dental lamina,
ectodermal cellsectodermal cells
multiply rapidly andmultiply rapidly and
forms knob likeforms knob like
structures called asstructures called as
enamel organs.enamel organs.
As cell proliferationAs cell proliferation
continues enamel organcontinues enamel organ
increases in size andincreases in size and
resembles a cap in shaperesembles a cap in shape

Late cap stage;Late cap stage;
1616
On the inside of theOn the inside of the
cap ectomesenchymalcap ectomesenchymal
cells proliferate fastercells proliferate faster
than surroundingthan surrounding
mesenchyme andmesenchyme and
formsforms dental papillae.dental papillae.

Bell stageBell stage
1717
 After the inner enamelAfter the inner enamel
epithelium differentiatesepithelium differentiates
into ameloblasts, theinto ameloblasts, the
peripheral connectiveperipheral connective
tissue cells of the dentaltissue cells of the dental
papillae differentiates intopapillae differentiates into
odontoblasts and startodontoblasts and start
producing dentine.producing dentine.
 It is at this time, when theIt is at this time, when the
first layer of dentine hasfirst layer of dentine has
formed that dental papillaeformed that dental papillae
is the called theis the called the dental pulpdental pulp

ZONES OF PULPZONES OF PULP
ODONTOBLAST LAYERODONTOBLAST LAYER
CELL-POOR ZONECELL-POOR ZONE
CELL-RICH ZONECELL-RICH ZONE
PULP PROPERPULP PROPER

ODONTOBLAST LAYERODONTOBLAST LAYER
Present next to predentin with odontoblasticPresent next to predentin with odontoblastic
process passing through predentin into dentinprocess passing through predentin into dentin
Contains nerve fibers(AContains nerve fibers(Aδδ), capillaries,dendritic), capillaries,dendritic
cellscells
In the Coronal pulpIn the Coronal pulp
– Cells tall columnar, palisadingCells tall columnar, palisading
– Layers of 3-4 cellsLayers of 3-4 cells
– More odontoblasts per unit areaMore odontoblasts per unit area

Cells in the mid-root region are cuboidal andCells in the mid-root region are cuboidal and
appear flattened at the apical region.appear flattened at the apical region.
No.of odontoblasts per unit area in theNo.of odontoblasts per unit area in the
radicular pulp is reduced.radicular pulp is reduced.
Neighbouring odontoblasts exhibit junctionNeighbouring odontoblasts exhibit junction
complexes.complexes.

CELL POOR ZONECELL POOR ZONE
Present in coronal pulp next to odontoblastPresent in coronal pulp next to odontoblast
layer, also called WEIL’S zonelayer, also called WEIL’S zone
40µ wide & relatively free of cells40µ wide & relatively free of cells
Traversed byTraversed by
blood vesselsblood vessels
unmyelinated nervesunmyelinated nerves
cytoplasmic process of fibroblastscytoplasmic process of fibroblasts

 Nerve plexus of RashkowNerve plexus of Rashkow
 Presence/ absence of this zone depends onPresence/ absence of this zone depends on
the functional statusthe functional status
 Relatively diminished inRelatively diminished in
younger pulpyounger pulp
older pulpolder pulp

CELL RICH ZONECELL RICH ZONE
Present in subodontoblastic layerPresent in subodontoblastic layer
Prominent in coronal pulpProminent in coronal pulp
Contains more proportions of fibroblast thanContains more proportions of fibroblast than
pulp properpulp proper
Also contains macrophages, dendritic cells andAlso contains macrophages, dendritic cells and
lymphocytes.lymphocytes. Dr.MadhuBillaDr.MadhuBilla 2323

PULP PROPERPULP PROPER
It is the central mass of the pulpIt is the central mass of the pulp
Contains larger blood vessels and nervesContains larger blood vessels and nerves
Pulpal cells and fibroblasts are also seenPulpal cells and fibroblasts are also seen

STRUCTURAL ORGANIZATIONSTRUCTURAL ORGANIZATION

Odontoblast cellsOdontoblast process
Dentin Pulp

CELLS OF PULPCELLS OF PULP
ODONTOBLASTSODONTOBLASTS
FIBROBLASTSFIBROBLASTS
UNDIFFERENTIATED CELLSUNDIFFERENTIATED CELLS
IMMUNOCOMPETENT CELLSIMMUNOCOMPETENT CELLS
MAST CELLSMAST CELLS Dr.MadhuBillaDr.MadhuBilla 2727

ODONTOBLASTODONTOBLAST
Highly differentiated cells derived from neuralHighly differentiated cells derived from neural
crest cellscrest cells
4040μμ length and 5-7length and 5-7μμ widewide
During active phase, cells show increase inDuring active phase, cells show increase in
ER, golgi apparatus & secretory vesiclesER, golgi apparatus & secretory vesicles
After primary dentin formation dentin formingAfter primary dentin formation dentin forming
activity slows down with decrease in no.ofactivity slows down with decrease in no.of

ODONTOBLASTIC PROCESSODONTOBLASTIC PROCESS
It is a direct extention from cell body into theIt is a direct extention from cell body into the
dentinal tubuledentinal tubule
Diameter 3-4Diameter 3-4μμ, no cell organelles, no cell organelles
Has well developed cytoskeleton withHas well developed cytoskeleton with
microfilaments & microtubules. Mainlymicrofilaments & microtubules. Mainly
composed of protein- tubulin, actin andcomposed of protein- tubulin, actin and
vimentin.vimentin.

JUNCTIONAL COMPLEXJUNCTIONAL COMPLEX
Neighbouring odontoblasts exhibit a series ofNeighbouring odontoblasts exhibit a series of
junctional complexesjunctional complexes
They promote cell to cell adhesion and play aThey promote cell to cell adhesion and play a
role in maintaining polarity of odontoblasts.role in maintaining polarity of odontoblasts.

Junctional complexes have been classified by SeltzerJunctional complexes have been classified by Seltzer
and Bender as.and Bender as.
Impermeable junctions/ zona occludensImpermeable junctions/ zona occludens- The tight- The tight
junction, or zona occludens, is so classified because ofjunction, or zona occludens, is so classified because of
the fusion of adjacent plasma membranes.the fusion of adjacent plasma membranes.
Adhering junctions/ zona adherensAdhering junctions/ zona adherens: where a gap of: where a gap of
200-300A is seen. Under light microscopy, adhering200-300A is seen. Under light microscopy, adhering
junctions were referred to as intercellular bridges.junctions were referred to as intercellular bridges.

Communicating junctions/ gap junctionCommunicating junctions/ gap junction::
where a gap of 10-20A is seen. Communicatingwhere a gap of 10-20A is seen. Communicating
junctions, or gap junctions (nexus-typejunctions, or gap junctions (nexus-type
junctions), are sites of cell-to-celljunctions), are sites of cell-to-cell
communication between adjacent odontoblastscommunication between adjacent odontoblasts
and between odontoblasts and fibroblasts of theand between odontoblasts and fibroblasts of the
subodontoblastic layer.subodontoblastic layer.

JUNCTIONAL COMPLEXESJUNCTIONAL COMPLEXES

FUNCTIONS OFFUNCTIONS OF
ODONTOBLASTSODONTOBLASTS
Synthesis of organic matrixSynthesis of organic matrix
Synthesis of non collagenous substances likeSynthesis of non collagenous substances like
sialoprotein, phosphophoryn, osteocalcin,sialoprotein, phosphophoryn, osteocalcin,
osteonectin& osteopontinosteonectin& osteopontin
Intracellular accumulation of calciumIntracellular accumulation of calcium
Degradation of organic matrixDegradation of organic matrixDr.MadhuBillaDr.MadhuBilla 3434

FIBROBLASTSFIBROBLASTS
Maximum in number and have the capacity toMaximum in number and have the capacity to
synthesise and maintain connective tissuesynthesise and maintain connective tissue
matrix.matrix.
Main functionsMain functions
synthesise type I & type III collagensynthesise type I & type III collagen
synthesise non-collogenous proteinsynthesise non-collogenous protein
matrix- proteoglycans & GAGsmatrix- proteoglycans & GAGs
Synthetic cells have branched cytoplasmicSynthetic cells have branched cytoplasmic
extentions with nucleus at one end of the cell.extentions with nucleus at one end of the cell.
Common in young pulpCommon in young pulpDr.MadhuBillaDr.MadhuBilla 3535

Also have the capability of ingesting andAlso have the capability of ingesting and
degrading the same matrix. Thus these cellsdegrading the same matrix. Thus these cells
have dual function with pathways for bothhave dual function with pathways for both
synthesis and degradation of small size.synthesis and degradation of small size.
They play important role in inflammation andThey play important role in inflammation and
healinghealing
They release inflammatory mediatorsThey release inflammatory mediators
cytokines and growth factorscytokines and growth factors

FIBROBLASTFIBROBLAST

UNDIFFERENTIATEDUNDIFFERENTIATED
MESENCHYMEMESENCHYME
These mesenchymal cells are distributedThese mesenchymal cells are distributed
through out the pulp, frequently around thethrough out the pulp, frequently around the
perivascular areaperivascular area
They are stellate shaped with a high nucleus :They are stellate shaped with a high nucleus :
cytoplasmic ratiocytoplasmic ratio
Under adequate stimulus they mayUnder adequate stimulus they may
differentiate into odontoblast or fibroblast.differentiate into odontoblast or fibroblast.
In older pulp, their number and ability toIn older pulp, their number and ability to
differentiate comes downdifferentiate comes down

Appear larger than fibroblasts and areAppear larger than fibroblasts and are
polyhedral in shapepolyhedral in shape
Found along the pulp vessels in cell rich zoneFound along the pulp vessels in cell rich zone
and scattered throught out the central pulpand scattered throught out the central pulp
These are mainly totipotent cells and and whenThese are mainly totipotent cells and and when
need arises they may become odontoblastsneed arises they may become odontoblasts
,fibroblasts or macrophages,fibroblasts or macrophages

IMMUNOCOMPETENT CELLSIMMUNOCOMPETENT CELLS
They play a major role local inflammation andThey play a major role local inflammation and
immunity.immunity.
They are recruited from blood stream &They are recruited from blood stream &
remain as transient inhabitants in pulpremain as transient inhabitants in pulp
These cells areThese cells are
LymhpocytesLymhpocytes
MacrophagesMacrophages
Dendritic cellsDendritic cells
Mast cellsMast cells Dr.MadhuBillaDr.MadhuBilla 4040

LYMPHOCYTES IN PULPLYMPHOCYTES IN PULP
Present along the walls of blood vesselsPresent along the walls of blood vessels
CD8+ T lymphocytes > CD4+ TCD8+ T lymphocytes > CD4+ T
lymphocytes, B lymphocytes are very rare.lymphocytes, B lymphocytes are very rare.
Involved in initial immunodefenseInvolved in initial immunodefense
Plasma cells may be present in coronal pulpPlasma cells may be present in coronal pulp

MACROPHAGES IN PULPMACROPHAGES IN PULP
Described as histiocytesDescribed as histiocytes
Located close to blood vesselLocated close to blood vessel
Have several phenotypesHave several phenotypes
They express varying combinations of severalThey express varying combinations of several
macrophage associated antigens and so help inmacrophage associated antigens and so help in
T lymphocyte activationT lymphocyte activationDr.MadhuBillaDr.MadhuBilla 4242

MACROPHAGESMACROPHAGES
Dark staining nucleus with cytoplasmicDark staining nucleus with cytoplasmic
granulesgranules

DENDRITIC CELLSDENDRITIC CELLS
Discrete populations of hematopoeticallyDiscrete populations of hematopoetically
derived leucocytesderived leucocytes
Characterised byCharacterised by
▪▪ peculiar dendritic morphologypeculiar dendritic morphology
▪▪ expression of high amount ofexpression of high amount of
class II MHC moleculesclass II MHC molecules
▪▪ high motilityhigh motility
▪▪ capacity of antigen presentationcapacity of antigen presentation
to T lymphocytesto T lymphocytesDr.MadhuBillaDr.MadhuBilla 4444

MAST CELLSMAST CELLS
Occur in small groups in relation to bloodOccur in small groups in relation to blood
vesselsvessels
Present only during pulpal inflammationPresent only during pulpal inflammation
Cytoplasmic granules of these cells containCytoplasmic granules of these cells contain
▪▪Heparin- anticoagulantHeparin- anticoagulant
▪▪Histamine- inflammatory mediatorHistamine- inflammatory mediator

EXTRACELLULAR MATRIXEXTRACELLULAR MATRIX
Connective tissue fibersConnective tissue fibers
▪▪ CollagenCollagen
▪▪ ElastinElastin
▪▪ FibronectinFibronectin
Ground substanceGround substance
▪▪ ProteoglycansProteoglycans
▪▪ GlycosaminoglycansGlycosaminoglycans
Basement membraneBasement membrane

COLLAGENCOLLAGEN
Extra cellular structural protein, majorExtra cellular structural protein, major
constituent of connective tissueconstituent of connective tissue
It has a triple helical domain, formed by 3It has a triple helical domain, formed by 3
polypeptide chains(polypeptide chains(ααchains) bound bychains) bound by
hydrogen bonds & hydrophobic interactionhydrogen bonds & hydrophobic interaction
Fibrils display characteristic striation atFibrils display characteristic striation at
intervals of 64nm. Hallmark for identificationintervals of 64nm. Hallmark for identification
of collagen fibrils.of collagen fibrils. Dr.MadhuBillaDr.MadhuBilla 4747

COLLEGEN FIBRECOLLEGEN FIBRE

Type I:
▪present as thick striated fibrils
▪responsible for pulp architecture
Type III:
▪thinner fibrils, mainly distributed in cell free & cell
rich zones
▪contributes to the elasticity of pulp
Type IV:
▪present along the basement membrane of
blood vessels
Type V & VI:
▪seen to form dense meshwork of thin micro
fibrils through out the stroma

COLLAGEN FIBRESCOLLAGEN FIBRES
Seen in relation with fibroblastsSeen in relation with fibroblastsDr.MadhuBillaDr.MadhuBilla 5050

Collagen turnover is maintained by pulp
fibroblasts
During bacterial infection & inflammation,
collagenolytic activity is accelerated following
collagenase produced by bacteria, PMN &
fibroblasts
Collagen synthesis is accelerated during
reparative dentin formation.Dr.MadhuBillaDr.MadhuBilla 5151

ELASTIC FIBERELASTIC FIBER
Elastin molecules form the unit structure ofElastin molecules form the unit structure of
Elastic fibersElastic fibers
These elastin molecules join to form a randomThese elastin molecules join to form a random
coil structurecoil structure
This has the ability to expand and contract likeThis has the ability to expand and contract like
a rubber band.a rubber band.

Elastic fibers are first formed in bundles of
thin micro filaments called Oxytalan fibers
Elastin is then deposited inbetween oytalan
fibers to form elastic fibers.
Always associated with larger blood vessels

FIBRONECTINFIBRONECTIN
It is a multifunctional stromal glycoproteinIt is a multifunctional stromal glycoprotein
that exists asthat exists as
•• a circulatory plasma proteina circulatory plasma protein
•• a protein that attaches to cellsa protein that attaches to cells
•• insoluble fibrils forming a part of the extrainsoluble fibrils forming a part of the extra
cellular matrixcellular matrix
It plays a role in cell-cell & cell-matrixIt plays a role in cell-cell & cell-matrix
adhesionadhesion
Has a major effect on the proliferation,Has a major effect on the proliferation,Dr.MadhuBillaDr.MadhuBilla 5454

GROUND SUBSTANCEGROUND SUBSTANCE
It is a structureless mass, gel-like consistency,It is a structureless mass, gel-like consistency,
makes up the bulk of the pulpmakes up the bulk of the pulp
Consists complexes of proteins, carbohydrateConsists complexes of proteins, carbohydrate
and water.and water.
Broadly classified asBroadly classified as
GlycoaminoglycansGlycoaminoglycans
ProteoglycansProteoglycans Dr.MadhuBillaDr.MadhuBilla 5555

GLYCOSAMINOGLYCANSGLYCOSAMINOGLYCANS
GAG are branched polymers of glucosamine &GAG are branched polymers of glucosamine &
galactoseamine, along with ester sulfate groups,galactoseamine, along with ester sulfate groups,
uronic acid & carboxyl groupuronic acid & carboxyl group
4 main types:4 main types:
Chondroitin sulphate/dermatan sulphateChondroitin sulphate/dermatan sulphate
Keratin sulphateKeratin sulphate
Heparin sulphateHeparin sulphate
Hyaluronic acid (non-sulphated)Hyaluronic acid (non-sulphated)
GAG found in pulp is mainly chondroitinGAG found in pulp is mainly chondroitin
sulphate, dermatan sulphate & hyaluronic acidsulphate, dermatan sulphate & hyaluronic acid

PROTEOGLYCANSPROTEOGLYCANS
Proteoglycans consists of a central protein coreProteoglycans consists of a central protein core
with side chains of GAGswith side chains of GAGs
Due to presence of various structural groups ofDue to presence of various structural groups of
GAG, proteoglycans are hydrophilic & act asGAG, proteoglycans are hydrophilic & act as
polyanionspolyanions
Thus proteoglycans carry high –ve charge thatThus proteoglycans carry high –ve charge that
prevent diffusion of larger molecules butprevent diffusion of larger molecules but
attract cationic material.

ROLE IN PULPROLE IN PULP
During dentinogenesis, the ground substanceDuring dentinogenesis, the ground substance
show affinity for collagen and influenceshow affinity for collagen and influence
fibrinogenesisfibrinogenesis
Chondroitin sulfate has strong capacity to bindChondroitin sulfate has strong capacity to bind
with calcium and help in mineralisationwith calcium and help in mineralisation
Decorin is suggested to be synthesized byDecorin is suggested to be synthesized by
odontoblasts and may play a role in mineralodontoblasts and may play a role in mineral
nucleation

BASEMENT MEMBRANEBASEMENT MEMBRANE
It is a sheet like arrangement of extra cellularIt is a sheet like arrangement of extra cellular
protein matrix at the epithelial-mesenchymalprotein matrix at the epithelial-mesenchymal
interfaceinterface
Composed of 2 layersComposed of 2 layers
lamina densa - electron denselamina densa - electron dense
lamina lucida - electrolucentlamina lucida - electrolucent
Basement membrane is a product ofBasement membrane is a product of
connective tissue and epitheliumconnective tissue and epithelium

1-4µm wide, relatively cell free1-4µm wide, relatively cell free
Ultrastructurally it is also called as basalUltrastructurally it is also called as basal
lamina, but it is not just a membrane but but alamina, but it is not just a membrane but but a
basal complex consisting of lamina and fibresbasal complex consisting of lamina and fibres
Lamina densa contains type IV collagenLamina densa contains type IV collagen
coated with heparin sulphate and appears ascoated with heparin sulphate and appears as
chicken wire configurationchicken wire configuration
Anchoring fibrils which contain type VIIAnchoring fibrils which contain type VII
collagen are inserted into lamina densacollagen are inserted into lamina densa

FUNCTIONS:FUNCTIONS:
▪▪ Act as sieve between epithelium &Act as sieve between epithelium &
connective tissueconnective tissue
▪▪ Helps in organisation & differentiation byHelps in organisation & differentiation by
enabling interactions between extracellularenabling interactions between extracellular
molecules & cell surface receptorsmolecules & cell surface receptors

CIRCULATION OF THE PULPCIRCULATION OF THE PULP
Pulp organ is extensively vascularised withPulp organ is extensively vascularised with
blood vessels arising from superior & inferiorblood vessels arising from superior & inferior
alveolar arteries.alveolar arteries.
Pulp has a micro circulatory system whichPulp has a micro circulatory system which
lacks true arteries & veins.lacks true arteries & veins.
The largest vessels are arterioles & venulesThe largest vessels are arterioles & venules
which regulate the local interstitialwhich regulate the local interstitial
environment.

PULP VASCULATUREPULP VASCULATURE

Pulpal blood flow is more rapid than in mostPulpal blood flow is more rapid than in most
areas of bodythis is perhaps attributable to theareas of bodythis is perhaps attributable to the
fact that pulpal pressure is highest of bodyfact that pulpal pressure is highest of body
tissuestissues
Flow of blood in arterioles- 0.3-1mm/sec inFlow of blood in arterioles- 0.3-1mm/sec in
venules 0.15mm/sec and in capillariesvenules 0.15mm/sec and in capillaries
0.08mm/sec0.08mm/sec

Vessles consists of 3 layersVessles consists of 3 layers
• tunica intima: consists of squamous or cuboidaltunica intima: consists of squamous or cuboidal
endothelial cellsendothelial cells
•Tunica media: 5µ thick consists of smoothTunica media: 5µ thick consists of smooth
muscle cells, ocassionally the endothelial cellmuscle cells, ocassionally the endothelial cell
wall is in contact with muscle cells which iswall is in contact with muscle cells which is
termed myoendothelial junctiontermed myoendothelial junction
•Tunica adventitia: made of collagen fibresTunica adventitia: made of collagen fibres
forming a loose network around larger arteriesforming a loose network around larger arteries

CAPILLARIES:
•Function as exchange vessels regulating
the transport or diffusion of substances
between blood and local interstitial tissue
elements
• They consists of single layer of
endothelium surrounded by basement
membrane
• Capillary pressure: 35 mmHg
• Capillary wall is 0.5μ thick & acts as
semi permeable membraneDr.MadhuBillaDr.MadhuBilla 6666

VENULES:
• Collecting venules receive pulpal blood flow
from the capillaries & transfer it to the venules
• Arterio-venous anastomosis permits direct
shunting from arterioles to venules
• Venular pressure-19mmHg

LYMPHATICSLYMPHATICS
Lymphatic vessels are formed from a fine
meshwork of small, thin walled lymph
capillaries
They start as blind openings near Weil’s zone
& odontoblastic layer
The larger lymphatic vessels run along the
blood vessels & nerves

More numerous in in central part of pulp thanMore numerous in in central part of pulp than
in peripheral areasin peripheral areas
Those draining the anterior teeth pass toThose draining the anterior teeth pass to
submental lymphnodes and those draining thesubmental lymphnodes and those draining the
posterior teeth pass to submandibular and deepposterior teeth pass to submandibular and deep
cervical lymphnodes.cervical lymphnodes.

INNERVATIONINNERVATION
Principle role is to help in conscious
recognition of irritants to the pulp,
Dental pulp contains sensory and motor fibers
to fulfill the vasomotor and defense function
Sensory afferent fibers are branches of
maxillary & mandibular divisions of
trigeminal nerve.

After entering the foramen, they arborize.
Larger fibers are present in the central zone.
They divide as they proceed peripherally and
coronally.
Subjacent to the cell rich zone, the nerves
branch extensively forming a parietal layer of
nerves- NERVE PLEXUS OF RASHKOW.
This layer contains both Aδ and C fibers
.
In the cell free zone, they form a rich network
responsible for pain.

TYPES OF NERVE FIBRESTYPES OF NERVE FIBRES

NERVE FIBERSNERVE FIBERS
A-fibers C-fibers
•Myelinated •Unmyelinated
•20% •80%
•Diameter – 2-5µm •0.3-1.2µm
•Conduction velocity
6-30m/sec
• 0.4-2m/sec
•Distributed in odontoblastic &
subodontoblastic zones &
associated with Dental pain.
•Distributed throughout the pulp
tissue & associated with pain
due to pulp damage.
•Impulses are intercepted as
sharp & prickling pain.
•Conduct throbbing & aching
pain.
•Low threshold of excitability. •High threshold of excitability.

FUNCTIONS OF DENTALFUNCTIONS OF DENTAL
PULPPULP
INDUCTIVE
FORMATIVE
NUTRITIVE
PROTECTIVE
DEFENSE Dr.MadhuBillaDr.MadhuBilla 7474

INDUCTIVEINDUCTIVE
It induces epithelial differentiation into dental
lamina & enamel organ
It also induces the enamel organ to become a
particular type of tooth

FORMATIVEFORMATIVE
Pulp induces dentin formation that surrounds
& protects the pulp
This involves formation of primary &
secondary dentin
The primary dentin is tubular & regularly
arranged. Formed before root closure

NUTRITIVENUTRITIVE
Dental pulp maintains the vitality of dentin by
providing O2 & nutrients to the odontoblasts
Also provides continuing source of dentinal
fluid
Nutrition made possible by rich peripheral
capillary network Dr.MadhuBillaDr.MadhuBilla 7777

PROTECTIVEPROTECTIVE
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 the blood
volume & rate of blood flow & hence the
intrapulpal pressureDr.MadhuBillaDr.MadhuBilla 7878

DEFENSEDEFENSE
When irritated or injured the pulp will respond
by
1. Dentinal pain
2. Smear layer formation
3. Tubular sclerosis
4. Irritation dentin formation
5. Inflammation of subjacent connective
tissue Dr.MadhuBillaDr.MadhuBilla 7979

REGRESSIVE CHANGESREGRESSIVE CHANGES
(AGING)(AGING)

Cell changesCell changes
-in addition to appearance of fewer cells in thein addition to appearance of fewer cells in the
aging pulp the cells are characterized byaging pulp the cells are characterized by
decrease in size and number of cytoplasmicdecrease in size and number of cytoplasmic
organellesorganelles
Fibrosis:
In aging pulp accumulation of both diffuse
fibrillary components and bundles of collagen
fibres usually appear

PULP CALCIFICATIONSPULP CALCIFICATIONS
It is a common occurrence with incidence of 50%It is a common occurrence with incidence of 50%
of all teethof all teeth
Size may range from microscopic particle toSize may range from microscopic particle to
stones that may occlude the pulp chamberstones that may occlude the pulp chamber
Composed of carbonated hydroxyapitite crystalsComposed of carbonated hydroxyapitite crystals
Pulp calcification may bePulp calcification may be
Pulp stonesPulp stones
Diffuse calcificationsDiffuse calcifications
Calcific MetamorphosisCalcific Metamorphosis

Pulp denticles, are classified as -Pulp denticles, are classified as -
According to structure:According to structure:
1)True denticles1)True denticles
2)False denticles2)False denticles
3)Diffuse calcifications3)Diffuse calcifications
According to location:According to location:
1)Free- entirely surrounded by pulp1)Free- entirely surrounded by pulp
2)Attached-partially fused with dentine.2)Attached-partially fused with dentine.
3)Embeded- entirely surrounded by dentine3)Embeded- entirely surrounded by dentine
8383
Goga, R., Chandler, N. P. and Oginni, A. O. (2008), Pulp stones: a review.
International Endodontic Journal, 41: 457–468

TRUE DENTICLESTRUE DENTICLES
Round or ovoid with smooth surfaces andRound or ovoid with smooth surfaces and
concentric lamellae.concentric lamellae.
Appear to grow by addition of collagen onAppear to grow by addition of collagen on
their surfacetheir surface
Believed to be formed around HERSBelieved to be formed around HERS
They contain dentinal tubules, and areThey contain dentinal tubules, and are
frequently found near root apex.frequently found near root apex.Dr.MadhuBillaDr.MadhuBilla 8484

FALSE DENTICLESFALSE DENTICLES
They have a rough surface no particular shape &
laminations
Grow due to mineralization of preformed
collagen fibers
Cause of such calcification may be, degenerating
cells, blood thrombi or collagen fibrils all of which
form a nidi for calcification
Usually present in the pulp chamber.Dr.MadhuBillaDr.MadhuBilla 8585

 True denticles are not dystrophic structures, since theyTrue denticles are not dystrophic structures, since they
are composed of dentin and formed by detachedare composed of dentin and formed by detached
dentinoblasts or fragments of Hertwig's sheath, whichdentinoblasts or fragments of Hertwig's sheath, which
may stimulate undifferentiated cells to assumemay stimulate undifferentiated cells to assume
dentinoblastic activity.dentinoblastic activity.
 False denticles are formed when a degenerating tissueFalse denticles are formed when a degenerating tissue
structure serves as a nidus for deposition of concentricstructure serves as a nidus for deposition of concentric
layers of calcified tissue.layers of calcified tissue.
8686

CalcificationsCalcifications
These are found in both healthy and aging pulps,These are found in both healthy and aging pulps,
although their incidence increases with agealthough their incidence increases with age

 Dystrophic calcification is a deposition of calcium salts in
dead or degenerating tissue. It may be due to local
alkalinity of the destroyed tissue that attracts the salts.
This mineralization thus may occur in minute areas of
young pulp tissue affected by minor circulatory
disturbance.
 Diffuse calcifications are generally observed in the root
canal but may also be seen in the pulp chamber.
8989

AGE CHANGESAGE CHANGES
Formation of secondary dentin through outFormation of secondary dentin through out
life, reduces the size of the pulp chamber &life, reduces the size of the pulp chamber &
root canalsroot canals
Decrease in cellularityDecrease in cellularity
Odontoblast decrease in size & number, &Odontoblast decrease in size & number, &
may disappear in certain areas. Especially onmay disappear in certain areas. Especially on
pulpal floor over bifurcation & trifurcationpulpal floor over bifurcation & trifurcation

Increase in number & thickness in collagenIncrease in number & thickness in collagen
fibers particularly in radicular pulpfibers particularly in radicular pulp
Reduction in the nerve fibers & blood vesselsReduction in the nerve fibers & blood vessels
Increase resistance of pulp against action ofIncrease resistance of pulp against action of
enzymesenzymes
In dentin,In dentin,
Increase in peritubular dentinIncrease in peritubular dentin
Dentinal sclerosis, reduces permeabilityDentinal sclerosis, reduces permeability
Increase in dead tractsIncrease in dead tracts

CLINICAL CONSIDERATIONSCLINICAL CONSIDERATIONS
Anatomic considerationsAnatomic considerations
Effect of dental materials on pulpEffect of dental materials on pulp
Effect of Operative ProceduresEffect of Operative Procedures
Effects subsequent to restorationEffects subsequent to restoration

ANATOMICANATOMIC
CONSIDERATIONSCONSIDERATIONS
Dimensions of tooth preparation are dictatedDimensions of tooth preparation are dictated
by pulpal morphologyby pulpal morphology
Young permanent teeth have wider pulpYoung permanent teeth have wider pulp
chamber and so do deciduous teethchamber and so do deciduous teeth
Cervical horns present in maxillary molarsCervical horns present in maxillary molars
complicate class V restoration and endodonticcomplicate class V restoration and endodontic
treatmenttreatment
developmental disturbances and advanced agedevelopmental disturbances and advanced age

ANATOMICANATOMIC
CONSIDERATIONSCONSIDERATIONS

EFFECT OF DENTALEFFECT OF DENTAL
MATERIALS ON PULPMATERIALS ON PULP
Amalgam
corrosion products inhibit cell growth
high thermal conductivity
Glass ionomers
well tolerated by pulp
RMGI used for direct pulp capping
Zinc Oxide Eugenol
has an anti-bacterial and anodyne effect
higher concentrations leads to chronic
inflammation & thrombosis of vessels

Zinc Phosphate
strong to moderate cyto-toxic reactions is due to
leeching of zinc ions and low pH
Resin adhesive systems
The formation of hybrid layer secures the enamel-
resin interface with a continuous seal which acts as a
biometric barrier Dentin bonding agents monomer
molecules reaching the pulp can irritate the pulp
causing inflammation

EFFECTIVE DEPTHEFFECTIVE DEPTH
The effective depth is the area of minimumThe effective depth is the area of minimum
thickness of sound dentin separating the pulpalthickness of sound dentin separating the pulpal
tissue from the carious lesiontissue from the carious lesion
 2mm or more, healthy reparative reaction2mm or more, healthy reparative reaction
 0.8 – 2mm, unhealthy reparative reation0.8 – 2mm, unhealthy reparative reation
 0.3 – 0.8mm, pulpal destructon0.3 – 0.8mm, pulpal destructon
(Marzouk, 2006)(Marzouk, 2006)

CONCLUSIONCONCLUSION
9898
 Pulp to the tooth is like heart to the body,
providing constant source of nutrition to maintain
the vitality of the tooth. Every precaution should
be taken to preserve the vitality of the tooth.
 The preservation of the healthy pulp during
operating procedure and successful management in
cases of diseases are two most important challenge
to the clinicians

REFERENCESREFERENCES
 GROSSMANS ENDODONTIC PRACTICEGROSSMANS ENDODONTIC PRACTICE
 S.COHENS PATHWAYS OF PULP-9S.COHENS PATHWAYS OF PULP-9THTH
EDITIONEDITION
 ORBANS ORAL HISTOLOGYORBANS ORAL HISTOLOGY
 TEN CATES ORAL HISTOLOGYTEN CATES ORAL HISTOLOGY
 SELZERS AND BENDERS THE DENTAL PULPSELZERS AND BENDERS THE DENTAL PULP
 R. INOKIS DYNAMIC ASPECTS OF DENTAL PULPR. INOKIS DYNAMIC ASPECTS OF DENTAL PULP
 FRANKLIN S. WEINE – 5FRANKLIN S. WEINE – 5THTH
EDITIONEDITION

THANK YOU….THANK YOU….

Dental Pulp

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