PULP-Theory class.ppt

Pulp

1. Pulp
Dr.Smitha Dr.Smitha Rao

2. Pulp
Mesenchymeconnectivetissue
thatoccupiespulpcavityinthe
centralpartoftheteeth
Surroundedbydentinonallsides
exceptattheapicalforamen&
accessorycanalopenings

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

5. Pulp tissue removed during
endodontic therapy by a size 20
broach file

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
Molarpulpsare3-4timeslargerthan
incisorpulps

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.

9. Anatomy:
pulp
Coronal pulp
Radicular pulp

10. Coronal pulp
Haspulphornswhichareprotrusions
thatextendintothecuspsofeachcrown
Numberdependsonthecuspalnumber
Pulpbecomessmallerwithage

12. Radicular pulp
Extendsfromthecervicalregionofthe
crowntotherootapex
Anteriorteeth-single
Posteriorteeth-multiple
Continuouswiththeperiapical
connectivetissuesthroughthe
apicalforamen

13. Histology
4zones:
Odontoblasticzone
Cellfreezoneofweil
Cell-richzone
PulpCore

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.

17. Structure of pulp:
Intercellular
substance
Pulp
Cells

18. Structure of pulp:
Cells
Odontoblasts
Fibroblasts
Immunocompetent
cells
Macrophages
Undifferentiated
ectomesenchymal cells

19. Odontoblasts:
Secondmostprominentcellsofpulp
palisadepatternofarrangementinthe
crownofthematuretooth
Constantlocationadjacenttothe
predentin-odontogeniczoneofthe
pulp
Cellbodyinpulp&cellprocessesinthe
dentinaltubules
Tallcolumnarincrown,cuboidalin
middleofroot&flatspindleshapednear
theapexoftooth

21. Microvasculature of dental pulp:

23. Odontoblasts:
Diameter-5-7micronm
Length-25-40micronm
Pulp-dentineinterface-59,000-76,000per
squaremillimeterincoronaldentinwithlessin
root
Activecell-elongated,basallyplacednucleus&
abasophiliccytoplasm
Restingcell-stubby,littlecytoplasm&
haematoxyphilicnucleus
Transitionalstage-intermediatebeteenactive
&restingstage

24. Odontoblasts:
Undergoapoptoticcelldeath–shownby
markerbcl-2
Releaseinterleukin-8
Nitricoxidesynthetasehavebeen
identifiedinodontoblasts

25. Fibroblasts:
Cellsoccurringingreatestnumbers
inthepulp
Moreinnumberinthecoronal
portionofpulpwheretheyformthe
cell-richzone
Form&maintainthepulpmatrix,
whichconsistsofcollagen&ground
substance

26. Fibroblasts:
Theyfunctionincollagenfiber
formation
Inyoungpulpthecellsdivide&are
activeinproteinsynthesis
Inolderpulptheyappearrounded
orspindleshapedwithshort
processes& exhibitfewer
intracellularorganelles–fibrocytes

27. Fibroblasts:
Immaturepulp-cellularelements
predominate
Maturepulp-fibrouscomponents
predominate
Dualfunction;Inadditionto
formingthepulpmatrix,capableof
ingesting&degradingthesame
matrix

28. Fibroblasts….
SecreteangiogenicfactorslikeFGF-2
&VEGF
Secretecolonystimulatingfactor
Incellcultureonstimulationform
mineralizedtissue

30. Macrophages
Ovalorspindleshaped
Macrophagesarepresentinthenormal
dentalpulp&aremoredensearoundthe
bloodvesselsoftheinnerpulp&around
theodontoblastlayer

31. Dendriticcells:
Bonemarrow-derived,antigen
presentingdendritecellsarefound
in&aroundtheodontoblastlayerin
noneruptedteeth&ineruptedteeth
beneaththeodontoblastlayer
FunctionissimilartoLangerhans
cellsinthattheycapture&present
foreignantigentotheTcells

32. Dendriticcells:
Participateinimmunosurveillance
&increaseinnumberincarious
teeth
Dendriticcells&macrophages
constitutesome8%ofthetotal
cellpopulation,withdendritic
cellsexceedingmacrophages

33. Undifferentiated
ectomesenchymal cells
Totipotentcell
Dependinguponthestimulusthese
cellsmaygiverisetoodontoblasts,
fibroblastsormacrophages.
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
Groundsubstancelendsupporttothecellsof
thepulp&alsoserveastransportmediumof
nutrientsfromthebloodvesselstothecells&
transportofmetabolitesfromcellstoblood
vessels

35. Pulpal stem cells
Migratetothesiteofinjured
odontoblasts&producedentin
TGFbeta1&BMP-2involvedinthe
migrationofstemcells
Pluripotent-adipocytes&neuralcells

36. Pulpal stem cells
Produce dentinogenesis &
osteogenesis
Dentinsialoproteinpresent
Dentoninstimulatedentalpulpstem
cell
Pulptisueof3
rd
molars-viableafter
cryopreservation

37. Functions of pulp
1.Inductive: interactwithoral
epithelialcellsleading to
differentiationofdentallamina&
enamelorganformation
2.Formative:formationofdentin
3.Sensory:sensationoftoothisfelt
throughthenervesofthepulp

38. Functions of pulp
4.Nutritive:suppliesnutritiontothe
dentinthroughbloodvessels&
odontoblasticprocesses&maintainthe
vitalityoftooth
5.Defensiveorreparative:protectsit
self&vitalityofthetoothbyproducing
reparativedentin

39. Blood vessels of the dental pulp:
Supplyoxygen&nutrientswheretheyare
mostneededduringdentinogenesis
Pulpalbloodflow-
1.inarterioles-0.3to1mm/sec
2.Invenules-approx.0.15mm/sec
3.Incapillaries-approx.0.08mm/sec
Arise from inferior or superior alveolar
artery

40. Blood vessels of the dental pulp:
Pericyteliesonthesurfaceofvessels
Arterio-venousshuntsregulatebloodflow
Blood capillaries–8-10micromin
diameter
Fenestratedcapillaries-rapidtransportof
metabolitesduringdentinogenesis

43. Nerves of the dental pulp
Nervesenterpulpthroughapical
foramen,alongwithafferentblood
vessels&togetherformthe“neuro-
vascularbundle”
Nervebundlesthatenterthepulp
consistsprincipallyofsensoryafferentsof
thetrigeminalnerve&sympathetic
branchesfromthesuperiorcervical
ganglion

44. Nerves of the dental pulp
Inthecrownthereisapronounced
plexusofnervesbeneaththe
odontoblasts,knownastheplexusof
Raschkow–occupy the cell-
freezoneofweil&canbedemonstrated
insilverstainedsectionsunderlight
microscopeorbyimmunocytochemical
techniques
Intheroot-nocorrespondingplexus

47. AGE CHANGES OF PULP

48. Regressive changes (aging)
Fibrosis
•Accumulationofbothdiffusefibrillar
components&bundlesofcollagen
fibers
•Externaltraumasuchasdentalcariesor
deeprestorationscauseslocalized
fibrosisorscarringeffect
•Atheroscleroticplaquesmayappearin
pulpalvessels
•Calcificationsarefoundthatsurround
vessels

49. Regressive changes (aging)
Pulp stones (denticles):
•Nodular,calcifiedmassesappearingin
eitherorboththecoronal&root
portionsofthepulporgan
•Asymptomatic,unlesstheyimpingeon
nervesorbloodvessels
•Seeninfunctionalaswellasembedded
uneruptedteeth

51. Regressive changes (aging)
Pulp stones
(denticles):
True
denticles
False
denticles

52. Pulp stones:
Truedenticles:
•Similarinstructuretodentin
•Arerare,locatedclosetotheapicalforamen
•Developmentiscausedbytheinclusionof
remnantsoftheepithelialrootsheathwithin
thepulp
•Theseepithelialremnantsinducethecellsof
thepulptodifferentiateintoodontoblasts,
whichthenformthedentinmassescalled
truepulpstones

53. Pulp stones:
Falsedenticles:
•Donotexhibitdentinaltubules
•Concentriclayersofcalcifiedtissue
•Somecasescalcificationsitesappear
withinabundleofcollagenfibers
•Phleboliths-serveasnidiforfalse
denticles
•Alldenticlesbeginassmallnodules
butincreaseinsizebyincremental
growthontheirsurface

54. Pulp stones:

55. Pulp stones
(depending on their
relation to the
dentin of tooth)
Free
Attached
Embedded

57. Pulp stones:
Freedenticles:
entirelysurroundedbypulptissue
Attacheddenticles:
partlyfusedwiththedentin
Embeddeddenticles:
entirelysurroundedbydentin

58. Pulp stones:
Incidence–
66%ofteeth-10-3oyears
80%ofteeth-30&50years
90%-over50yearsofageFree
denticles:

59. Diffuse calcifications
Irregularcalcifieddeposits
followingcollagenfibrebundlesor
bloodvessels
Foundmoreintherootcanal&
lessincoronalarea
Surroundbloodvessels-dystrophic
calcification

60. Diffuse calcifications

61. Clinical considerations:
Wide pulp chamber in the tooth of a
young person will make a deep cavity
preparation hazardous
Dehydration cause pulpal damage
Associatedwithtrauma,thepulp
becomestransformedintogranulation
tissueandthedentinecommencestobe
resorbedinternallyatthepulp-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

63. 4. Chemical irritation –erosion
acidic restorative material
5. Thermal changes –polishing procedures
cavity preparation
tooth restored with
exothermic
restorative
material.
6. Galvanic currents
7. Periapical tissue –accessory canals
8. Aerodontalgia

64. Classification of
pulpitis
•Acute
•Chronic
•Both acute and chronic –
Partial or focal pulpitis
Total or generalised
•Closed pulpitis
•Open pulpitis

65. References
Orban’s oral histology &embryology-12
th
edition
Ten Cate’s oral histology-7
th
edition
Oral anatomy, histology and embryology;
Berkovitz, 3
rd
edition
Essentials of oral histology &
embryology, 2rd edition, James k . avery

66. Thank you
Thank you