8 pulp

3. The dental pulp is that loose The dental pulp is that loose
delicate connective tissue delicate connective tissue
occupying the cavity lying occupying the cavity lying
in the center of dentin.in the center of dentin.

4. *The coronal pulp*The coronal pulp: it is present in : it is present in
the pulp chamber. the pulp chamber.
*The radicular pulp*The radicular pulp:: it is that part it is that part
of the pulp extending from the of the pulp extending from the
cervical region of the crown to the cervical region of the crown to the
root apex. root apex.
MorphologyMorphology

5. Accessory canals:Accessory canals:
They are commonly seen to extend They are commonly seen to extend
from radicular pulp laterally from radicular pulp laterally
through the root dentin to the through the root dentin to the
periodontal ligament. periodontal ligament.
They are They are numerousnumerous in the apical in the apical
third of the root.third of the root.
Accessory Accessory
canalscanals

6. 1- it occurs in areas, where the developing root 1- it occurs in areas, where the developing root
encounters a encounters a large blood vessellarge blood vessel, where , where
dentin will be formed around it.dentin will be formed around it.
2- 2- Early degenerationEarly degeneration of the epithelial root of the epithelial root
sheath of Hertwig before the differentiation of sheath of Hertwig before the differentiation of
the odontoblasts.the odontoblasts.

3-Lack of complete union of the 3-Lack of complete union of the epithelial epithelial
diaphragmdiaphragm at the floor of the pulp chamber. at the floor of the pulp chamber.
Mechanism of formation accessory Mechanism of formation accessory
canalscanals

7. *Apical foramen*Apical foramen:: The pulp organs are continuous The pulp organs are continuous
with the periapical tissue through the apical foramen. with the periapical tissue through the apical foramen.
The average sizeThe average size of the apical foramen: of the apical foramen:
maxillary teeth : maxillary teeth : 0.4 mm0.4 mm
mandibular teeth : mandibular teeth : 0.3mm0.3mm

8. Pulp ExposurePulp Exposure

9. Infected
pulp
Abcess

12. Dental pain occurs in 12% of population. population.
Dental pain is the most unkilling acute painDental pain is the most unkilling acute pain
affecting human being.affecting human being.
The origin of the dental
pain is difficult to localize.
(referred pain)
Dental pain Dental pain (acute pulpitis)(acute pulpitis)

13. Loss of the pulp Loss of the pulp
results in loss of the results in loss of the
pulp functions, but pulp functions, but
the tooth is still the tooth is still
functioningfunctioning

14. The dental pulp is formed of The dental pulp is formed of specializedspecialized loose loose
connective tissue: connective tissue:


Histological structure of the Histological structure of the
pulppulp
cells fibersfibersintercellular substancesintercellular substances

blood vessels and nervesblood vessels and nerves

15. peripheral zone peripheral zone
(odontogenic zone).(odontogenic zone).
Central zone Central zone
(pulp core).(pulp core).
Zones of the pulpZones of the pulp
Dentin

16. Odontogenic zone:Odontogenic zone:
a- odontoblasts: a- odontoblasts:
Location: ALocation: Adjacent to the predentin with djacent to the predentin with
the cell bodies in the pulp and cell the cell bodies in the pulp and cell
processes in the dentinal tubules. processes in the dentinal tubules.
Dentin

17. B- Cell free zone B- Cell free zone ((the zone of the zone of WeilWeil)): :
**It is present beneath the odontoblastic layer.It is present beneath the odontoblastic layer.
**It is suggested to be the area of mobilization It is suggested to be the area of mobilization
and replacement of odontoblasts. and replacement of odontoblasts.
C- cell rich zone:C- cell rich zone:
It is present beneath It is present beneath
the cell free zone.the cell free zone.
It is composed of It is composed of
fibroblasts and fibroblasts and
undifferentiated undifferentiated
mesenchymal cells.mesenchymal cells.

18. odontogenic odontogenic
zone zone

19. Cell free zone & cell Cell free zone & cell
rich zone might be rich zone might be
artifactsartifacts..

20. Cells of the pulpCells of the pulp
2- Synthetic cells (formative cells):2- Synthetic cells (formative cells):
Odontoblasts and fibroblasts.Odontoblasts and fibroblasts.
Macrophages, lymphocytes, eosinophils, Macrophages, lymphocytes, eosinophils,
mast cells and plasma cells. mast cells and plasma cells.
3- Defensive cells:3- Defensive cells:
1- Progenitor cells:1- Progenitor cells:
Undifferentiated mesenchymal cells.Undifferentiated mesenchymal cells.

21. 1- Progenitor cells:1- Progenitor cells:
(UMC):(UMC):
They are They are smallersmaller than fibroblasts than fibroblasts
but have a similar appearance. but have a similar appearance.
They are usually found They are usually found alongalong the the
walls of blood vessels. walls of blood vessels.
These cells have the These cells have the potentialitypotentiality
of forming other types of of forming other types of
formative or defensive cells.formative or defensive cells.

22. A- OdontoblastsA- Odontoblasts
Length: Length: 25-40u25-40u
Diameter: Diameter: 5-7u5-7u
In the early stagesIn the early stages of development of development
odontoblasts consist of a odontoblasts consist of a single layer of single layer of
columnarcolumnar cells . cells .
In the later stagesIn the later stages of development, the of development, the
odontoblasts appeared odontoblasts appeared pyriformpyriform where where
the broadest part of the cell contains the the broadest part of the cell contains the
nucleusnucleus
2-Formative cells:

23. Odontoblasts areOdontoblasts are
longerlonger in the crown in the crown

cuboidalcuboidal rootwise,rootwise,

flatflat at the root apexat the root apex

24. The cell membranes of adjacent odontoblasts The cell membranes of adjacent odontoblasts
exhibit junctional complexes.exhibit junctional complexes.
The clear terminal part of the cell body and the The clear terminal part of the cell body and the
adjacent intercellular junction is known as adjacent intercellular junction is known as
terminal bars.terminal bars.
Gap junction
desmosome

25. B- B- FibroblastsFibroblasts
*These are the most *These are the most numerousnumerous
type of pulp cells.type of pulp cells.
*They are *They are spindlespindle in shape. in shape.
*They have *They have elongated processeselongated processes which which
are link up with those of other pulpal are link up with those of other pulpal
fibroblasts (fibroblasts (stellatestellate appearanceappearance). ).
*The *The nucleusnucleus stains deep with stains deep with
basic dye and the basic dye and the cytoplasmcytoplasm is is
highly stained and homogenous. highly stained and homogenous.

27. These cells have a double function: These cells have a double function: formation formation and and
degradationdegradation of fibers and ground substances. of fibers and ground substances.
In young pulp, they are :In young pulp, they are :
*Large cells .*Large cells .
*With large multiple processes *With large multiple processes
*Centrally located oval nucleus, *Centrally located oval nucleus,
*Numerous mitochondria, *Numerous mitochondria,
*Well developed Golgi bodies*Well developed Golgi bodies
*Well developed RER*Well developed RER
mitochondriamitochondria
FibroblastFibroblast
protein protein
secreting cellsecreting cell

28. In periods of In periods of less activity and agingless activity and aging they they
appear smaller and round or spindle-shaped with appear smaller and round or spindle-shaped with
few organelles, they are termed few organelles, they are termed fibrocytesfibrocytes..
fibrocytefibrocyte
fibroblastfibroblast

29. Infected pulpInfected pulp
L
L

30. 3- Defensive cells:3- Defensive cells:
A- Histiocyte (macrophage):A- Histiocyte (macrophage):
They appear irregular in They appear irregular in shapeshape with with
short blunt processes.short blunt processes.

The The nucleusnucleus is small, more rounded & is small, more rounded &
darker in staining than fibroblast.darker in staining than fibroblast.
They are They are distributeddistributed around the around the
odontoblasts and small blood vessels odontoblasts and small blood vessels
and capillaries. and capillaries.

31. In case of inflammationIn case of inflammation::
*Nuclei increase in size and exhibit *Nuclei increase in size and exhibit
a prominent nucleolus.a prominent nucleolus.
*It exhibits granules and vacuoles *It exhibits granules and vacuoles
in their cytoplasm. in their cytoplasm.
UltastructurallyUltastructurally, ,
invaginations of plasma membrane invaginations of plasma membrane
with aggregation of vesicles or with aggregation of vesicles or
phagosomes .phagosomes .

32. *Macrophages are involved
in the elimination of dead
cells.
*Macrophages remove
bacteria and interact with
other inflammatory cells to
protect the pulp during
inflammation.

33. L

34. PhagocytosisPhagocytosis
Hydrolytic
enzymes

35. B-B- Plasma cells: Plasma cells:
These cells are seen during These cells are seen during
inflammationinflammation. .
The nucleus of this cell is small and The nucleus of this cell is small and
appears appears eccentriceccentric in the in the
cytoplasm. cytoplasm.
The arrangement of chromatin in The arrangement of chromatin in
the nucleus gives the cell a the nucleus gives the cell a cart cart
wheelwheel appearance, appearance,
The plasma cells are known to The plasma cells are known to
produce produce antibodiesantibodies..

36. C- C- LymphocytesLymphocytes
They are found in normal They are found in normal
pulp and they increase pulp and they increase
during inflammation.during inflammation.

37. D-EosinophilsD-Eosinophils
They are found in They are found in
normal pulp and they normal pulp and they
increase during increase during
inflammation.inflammation.

38. E-E- Mast cells Mast cells::
*They have a round nucleus and their *They have a round nucleus and their
cytoplasm contains many cytoplasm contains many granulesgranules. .
*They are demonstrated by using *They are demonstrated by using
specific stains as specific stains as toluidine bluetoluidine blue..
*They produce *They produce histamine& heparin.histamine& heparin.

39. The ground substances of the pulp:The ground substances of the pulp:
*The ground substances consists of acid *The ground substances consists of acid
mucopolysaccharides and neutral glycoprotein.mucopolysaccharides and neutral glycoprotein.
*These substances are the environment that *These substances are the environment that
promotes life of the cells.promotes life of the cells.
**GlycoseaminoglycansGlycoseaminoglycans are bulky molecules are bulky molecules
and hydrophilic, they form and hydrophilic, they form gelsgels that fill most of that fill most of
the extracellular space, They contribute to the the extracellular space, They contribute to the
high tissue fluid pressurehigh tissue fluid pressure of the pulp. of the pulp.

40. Blood vesselsBlood vessels
*The pulp is highly vascularized. It is*The pulp is highly vascularized. It is
supplied by the supplied by the inferior and superior inferior and superior
alveolar arteries. alveolar arteries.
*As the vessels enter the tooth, their *As the vessels enter the tooth, their
walls become considerably walls become considerably thinner thinner
than those surrounding the tooth. than those surrounding the tooth.
*Along their course they give numerous *Along their course they give numerous
branches in the radicular pulp that branches in the radicular pulp that
pass pass peripherallyperipherally to form a to form a plexusplexus in in
the odontogenic region. the odontogenic region.
D

41. The rate of blood flow in the pulp of the tooth is The rate of blood flow in the pulp of the tooth is four four
timetime the rate of blood flow in resting muscle. the rate of blood flow in resting muscle.

Laser Doppler Laser Doppler
Flowmetry Flowmetry
It measures the rate of It measures the rate of
pulpal blood flowpulpal blood flow

42. The capillaries adjacent to the odontoblasts are The capillaries adjacent to the odontoblasts are
fenestratedfenestrated.. Such capillaries are found in areas Such capillaries are found in areas
of rapid exchange.of rapid exchange.

43. Current Current pulp testspulp tests assess the function of assess the function of
nervesnerves in the pulp, by the application of electric in the pulp, by the application of electric
current or a rapid change in temperature.current or a rapid change in temperature.
Recently, , blood flow rateblood flow rate in the pulp is used in the pulp is used
to measure the degree of the pulp vitality.to measure the degree of the pulp vitality.
Assessment of pulp vitality

44. Nerves of the pulpNerves of the pulp
The pulp has an abundant nerve supply The pulp has an abundant nerve supply
which follows the distribution of the which follows the distribution of the
blood vessels. blood vessels.
Two types of nerve fibers are Two types of nerve fibers are
present:present:
*Sympathetic in nature.*Sympathetic in nature.
They control the contraction of the They control the contraction of the
smooth muscles of the blood vessels. smooth muscles of the blood vessels.
*Sensory nerves.*Sensory nerves.
Both contain myelinated and Both contain myelinated and
unmyelinated axons.unmyelinated axons.

45. *More nerve endings are found in the *More nerve endings are found in the pulp hornspulp horns than in than in
other peripheral areas of the coronal or radicular pulp.other peripheral areas of the coronal or radicular pulp.
*As the mylelinated nerves run coronally, they give off
side branches and lose their myelin coat. They form
then sub-odontoblastic plexus of nerves known as
plexus of Rashkow. Few axons extend in-between the
odontoblasts to give the nerve endings.

46. Sensory response in the pulp Sensory response in the pulp cannot differentiatecannot differentiate
between heat, touch, pressure or chemicals. between heat, touch, pressure or chemicals.
This is because the pulp organs lack those This is because the pulp organs lack those
types of receptors.types of receptors.

Heat, Heat,
Touch,Touch,
Pressure, Pressure,
ChemicalsChemicals
Pain

47. 1- Inductive:1- Inductive:
Dental papilla induces the enamel organ Dental papilla induces the enamel organ
formation and also determines the formation and also determines the
morphology of the tooth.morphology of the tooth.
Functions of the pulpFunctions of the pulp

48. 2- Formative :2- Formative :
Pulp organ produces dentin. Odontoblasts Pulp organ produces dentin. Odontoblasts
develop the organic matrix and function in its develop the organic matrix and function in its
calcification.calcification.

49. 3- Nutritive :3- Nutritive :
The pulp nourishes the dentin. Nutrition is The pulp nourishes the dentin. Nutrition is
mediated through the odontoblasts and mediated through the odontoblasts and
their processes.their processes.
Dentin

50. 4- Protective:4- Protective:
The sensory nerves in the tooth respond with The sensory nerves in the tooth respond with
pain to all stimuli, Pain sensation is a useful pain to all stimuli, Pain sensation is a useful
alarm systemalarm system of the pulp. of the pulp.

51. 5- Defensive or reparative:5- Defensive or reparative:
The pulp responds to irritation by producing The pulp responds to irritation by producing
reparative reparative dentin and dentin and mineralizing mineralizing any affected any affected
dentinal tubules. dentinal tubules.
These reparative reactions are an attempt to These reparative reactions are an attempt to
wall off the pulp from the source of irritation. wall off the pulp from the source of irritation.
The presence of macrophages, lymphocytes and The presence of macrophages, lymphocytes and
leucocytes aid in the process of repair of the leucocytes aid in the process of repair of the
pulp.pulp.

53. Age changes in the pulpAge changes in the pulp

The size of the pulp The size of the pulp
The apical foramenThe apical foramen
The cellular elements The cellular elements
The bl. vessels & n.The bl. vessels & n.
VitalityVitality
Reticular atrophy:Reticular atrophy: The total affect is the The total affect is the
production of a lessened vitality of the pulp production of a lessened vitality of the pulp
tissue and a lessened response to stimulation.tissue and a lessened response to stimulation.
decreased

54. Pulp clacificationPulp clacification
localized localized
((pulp stonespulp stones )
diffusediffuse
False denticle False denticle True denticleTrue denticle

55. True denticlesTrue denticles
They consist of They consist of irregular dentinirregular dentin
containing traces of dentinal containing traces of dentinal
tubules and few odontoblasts. tubules and few odontoblasts.
Remnants of the Remnants of the epithelial root epithelial root
sheathsheath invade the pulp tissues invade the pulp tissues
causing UMC of the pulp to form causing UMC of the pulp to form
thisthis irregular type of dentin.irregular type of dentin.
odontoblastodontoblast
dentinal dentinal
tubulestubules
True denticles are True denticles are rarerare &&
smallsmall in size& in size&
found near the found near the apical foramenapical foramen..

56. False denticlesFalse denticles
*They are evidence of *They are evidence of dystrophicdystrophic
calcification of the pulp tissue .calcification of the pulp tissue .
*They contain *They contain nono denti dentinnal tubules and al tubules and
can exist in any area of the pulp. can exist in any area of the pulp.
*They are formed of degenerated cells *They are formed of degenerated cells
or areas of hemorrhage which act as a or areas of hemorrhage which act as a
central central nidus nidus for calcification.for calcification.
*Overdoses of *Overdoses of vit. Dvit. D, may favor the , may favor the
formation of numerous denticles.formation of numerous denticles.

57. *Pulp stones are *Pulp stones are classifiedclassified according according
to their location into: free, to their location into: free,
attached and embedded. attached and embedded.
*They continue to increase in *They continue to increase in sizesize
and in certain cases they fill up and in certain cases they fill up
the pulp chamber completely.the pulp chamber completely.
*If pulp stones come close enough *If pulp stones come close enough
to a to a nervenerve bundle pain may be bundle pain may be
elicited. elicited.
*The close proximity of pulp stones *The close proximity of pulp stones
to to blood vesselsblood vessels may cause may cause
atrophy of it.atrophy of it.
freefree
attachedattached

58. Diffuse pulp calcificationDiffuse pulp calcification
*Commonly occurs on top of *Commonly occurs on top of
hyalinehyaline degenerationdegeneration in the in the
root canal and not common in root canal and not common in
the pulp chamber.the pulp chamber.
*They are *They are irregular calcific irregular calcific
depositiondeposition in the pulp tissue in the pulp tissue
following the course of blood following the course of blood
vessels or collagenous bundle. vessels or collagenous bundle.
*Advancing *Advancing ageage favors their favors their
development.development.