This document provides information about the dental pulp. It begins with definitions, morphology, development, and histology. It describes the pulp as a richly vascularized and innervated connective tissue contained within the dentin. It details the different zones of the pulp from the odontoblastic zone to the central zone. It discusses the cellular elements like odontoblasts and fibroblasts, neurovascular components, and age-related changes like reduction in size and sensitivity. In summary, the document is a comprehensive overview of the anatomy, histology, development and functions of the dental pulp.

2. DENTAL PULP
• Presented by:
• Taif Ahmad (10)
• Humayun Afridi (09)
• Saqib Habib (51)
ORAL BIOLOGY

3. Contents
• Definition
• Morphology
• Functions
• Histology
• Vasculature
• Innervation
• Age Changes
• Clinical Considerations

4. Learning Objectives
• At The end of this presentation, 2nd year B.D.S
students will be able to know about the dental
pulp INSHALLAH.

5. Definition
• Dental pulp can be
defined as a richly
vascularized and
innervated
connective tissue of
mesodermal origin
enclosed by dentin
with communication
to periodontal
ligament.

6. Development of Pulp
• The tooth pulp is initially
called DENTAL PAPILLA.
• Dental PAPILLA: During
8th week of IUL, under the
organizing influence of
proliferating epithelium of
enamel organ, the
ectomesenchyme that is
partially enclosed by
invaginated portion of
inner enamel epithelium
proliferates and condense
to form dental papilla.

7. Development of Pulp
• In the earliest stages
of tooth development
it is the area that
induces the oral
epithelium to
invaginate and serves
to start the formation
of enamel organ. The
enamel organ then
enlarge and enclose
dental papillae in their
central portion.

8. Development of Pulp
• The dental papilla becomes pulp only
after dentin forms around it.
• After inner enamel epithelium
differentiate into ameloblast, it induces
the peripheral cells of dental papilla to
differentiate into odontoblast and
dentin formation begins. As dentin
formation completed the inner portion
is now called dental pulp.

9. dental papilla
pulp
Both dentin and pulp have a common origin from the dental papilla.

10. Morphology of Pulp

11. Morphology
• General features: It
occupies the centre
portion of each
tooth and consists
of soft connective
tissue.
• It’s shape resemble
the shape of tooth in
which it is housed.

12. Morphology
• Every person normally has a total of 52 pulp
organs, 32 in the permanent & 20 in the primary
teeth.
• The total volume of all permanent teeth is 0.38cc
• The mean volume of single adult human pulp is
0.02cc
• Molar pulp are 3 to 4 times larger than incisor
pulp.
• Cuspid has the longest pulp.
• Mandibular central incisor has the smallest pulp.

13. Pulp Space
• The entire internal space of a tooth
which contains the pulp is called pulp
space. It consists of the following
entities.
1. Pulp chamber
2. Pulp canal
3. Pulp horn

14. 1)Pulp chamber
• The pulp space in the crown is called
pulp chamber.
• The pulp inside is called coronal pulp.
• It has six surfaces; the roof ,the floor,
the mesial, the distal, the buccal and
the lingual.

15. Floor
Roof
MesialDistal

16. 2)Pulp canal (root canal)
• The pulp space in the
root is called pulp
canal.
• The pulp inside is
called radicular pulp.
• In anterior teeth it is
single, in posterior
teeth it is multiple.
Root Canal

17. 3)Pulp horn
• A pulp horn is an
accentuation of the
pulp chamber.
• The number of these
horns depend on
cuspal number in
posterior teeth and
developmental lobes in
anterior teeth.
• The mesial pulp horns
are usually higher than
the distal pulp horns.

18. Classification of pulp space
• They are classified by F.J.Vertucci’s
into following 8 types.
• One canal at apex
Type I – TypeIII
• Two canals at apex
Type IV – Type VII
• Three canals at apex
Type VIII

19. Type I
• Single canal extending from pulp
chamber to the apex.

20. Type II
• Two canals leave the pulp chamber and
joins short of the apex to form one
canal.

21. Type III
• One canal leaves the pulp chamber,
divides into two, within the root and
then merges to unite as one canal.

22. Type IV
• Two separate canals from chamber to
apex.

23. Type V
• Leaves pulp chamber as one and divides
short of the apex into 2 separate apical
foramina.

24. Type VI
• Two separate canals leave the pulp
chamber and merge in the middle body
of the root then re-divides short of the
apex.

25. Type VII
• One canal leaves the pulp chamber
divides and then rejoins within the body
and finally re-divides into 2 distinct
canals short of the apex

26. Type VIII
• Three separate and distinct canals
extend from pulp chamber to the apex.

28. Canal orifices
• The canal orifices are openings in the floor of
the pulp chamber leading into the pulp space.
Canal Orifices

29. The apical foramen
• Pulp cavity
terminates at root
apex as small opening
called apical foramen
• The pulp organs are
continuous with the
periapical tissue
through the apical
foramen.
Apical Foramen

30. The apical foramen
• The average size
of the apical
foramen is:
• maxillary teeth:
0.4 mm
• mandibular teeth:
0.3 mm

31. The apical foramen
• As the root begins
to develop, the
apical foramen is
actually larger than
the pulp chamber,
but it becomes more
constricted at the
completion of root
formation.

32. Apical constriction
• Narrowest portion
at the terminal end
of the pulp space.
• It is approximately
0.5 mm. short of the
apical foramen
Apical Constriction
Apical Foramen

33. Accessory canal
• The pulp cavity is
sometimes
connected with the
periodontal tissue
with an opening
rather than the
apical foramen,
called the lateral,
accessory or
supplementary canal.

34. Accessory canal
• They are numerous
in the apical third of
the root and in the
bifurcation of
multirooted teeth.

35. Delta System
• If the root canal
breaks up into
multiple tiny canals,
it is referred to as a
delta system
because of its
complexity.

36. Etiology of accessory canals
1. Degeneration of the epithelial root
sheath of Hertwig before odontoblasts
differentiation.
2. Large blood vessel disturbs the course
of the root sheath.

37. Functions

38. 1) Inductive:
• Dental papilla induces the enamel organ
formation .
• It also induces the enamel organ to
differentiate into a particular type of tooth
morphology.

39. 2) Formative
• The cells of Pulp induces dentin formation.
• This involves formation of primary and
secondary dentin.
• The primary dentin is tubular and regularly
arranged, formed before root closure.
• Secondary dentin contain fewer tubules and is
formed after root closure.

40. Nutritive
Dental pulp maintains the vitality of
dentin by providing O2 and nutrients to
the odontoblasts.
Nutrition is made possible by rich
peripheral capillary network.

41. Protective
• 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 and rate of blood flow and hence the
intrapulpal pressure.

42. 5- Defense:
The pulp responds to
irritation by producing
reparative dentin and
mineralizing any affected
dentinal tubules.
These reparative
reactions are an attempt
to wall off the pulp from
the source of irritation.
The presence of
macrophages,
lymphocytes and
leucocytes aid in the
process of repair of the
pulp.

43. HISTOLOGY OF PULP
By
Humayun Afridi

44. HISTOLOGY
• When the pulp is examined microscopically
four distinct zones can be distinguished
from outer to inner.
o The odontoblastic zone.
o The cell free zone or Weil’s zone.
o The cell rich zone.
o The central zone.

46. Odontoblastic zone
• It is the peripheral
layer of pulp
adjacent to
predentin
• This zone is
composed of cell
bodies of
odontoblast.

47. Cell free zone (weil’s zone)
• It is also called weil’s zone
• 40 microns wide & relatively
free of cells, Traversed by
1. blood vessels
2. unmyelinated nerves
3.cytoplasmic process of
fibroblasts
• This zone is found below the
odontoblastic zone
• Represents the space into
which odontoblasts move
during tooth development.

48. Cell rich zone
• It lies beneath cell
free zone.
• Contains more
proportion of
fibroblast and
undifferentiated
mesenchymal cells.
• Also contains
macrophages,
dendritic cells etc.
• Mitosis seen when
dead odontoblasts are
replaced

49. Central zone
• This zone is also
called pulp core
• It contains blood
vessels and nerves
embedded in the
pulp matrix together
with fibroblasts.

50. Odontoblasts
Predentin
Cell-free zone
Cell-rich zone
Central Zone

51. Components of Pulp
• As it is a connective tissue, it contains the following
components.
• 1) Cellular elements :
a. Formative cells : Odontoblast, Fibroblast .
b. Progenitor cells : Undifferentiated mesenchymal
cells .
c. Defensive cells : Macrophages, neutrophils,
eosinophils, basophils, mast cells , plasma cells and
Lymphocytes.
• 2) Matrix
• 3) Neurovascular elements :

52. •CELLULAR ELEMENTS

53. a)Formative cells
Odontoblast
The second most
prominent cell in the
pulp, resides adjacent
to predentin with cell
bodies in the pulp and
cell processes in the
dentinal tubules.
Numbers corresponds
to dentinal tubules.

54. Shape may vary,
cornal pulp- columnar
Midportion - cuboidal
Apical region–Flattened

55. Function of odontoblast
• It’s main function is
dentin formation.

56. Fibroblasts
• These are the most
abundant cells in the
pulp
• Shape: They are
spindle in shape.
• They have elongated
processes which are
widely separated and
link up with those of
other pulpal
fibroblasts (stellate
appearance).

57. • These cells have a dual
function: synthesize and
degradation of fibers
and ground substances
in pulp .
• in periods of less
activity and aging these
cells appear smaller and
round or spindle-shaped
with few organelles ,
they are termed
fibrocytes.
fibroblastfibrocyte

58. • Progenitor cells

59. (The undifferentiated mesenchymal cells):
They are smaller than
fibroblasts but have a
similar appearance.
They are usually found
along the walls of
blood vessels.
These cells have the
potentiality of
forming other types
of formative or
defensive connective
tissue cells.

60. • DEFENSE CELLS

61. Lymphocytes and plasma cells:
 These cells are not normally
present in healthy pulp tissue
but are associated with injury
and resultant immune responses
attempts to destroy, damage,
or neutralize foreign
substance.
 These inflammatory cell types
generally appear following
invasion into the area of injury.
plasma cells
Lymphocyte

62. Macrophages
• Described as histiocytes (or) as
resting wandering cells
• Located close to blood vessel
• Have several phenotypes
• Macrophages are phagocytes,
function of which are
engulfment and digestion of the
foreign material
• During inflammation they appear
in large number to aid in
defense of the organism

63. Mast cells:
 Mast cells are seldom in
large numbers in normal,
healthy pulps, but are
commonly found in
inflamed pulps.
 Have granular cytoplasm
with round nucleus.
 They produce histamin &
heparin.

64. Matrix
• COLLAGEN
• ELASTIN
• FIBRONECTIN
• LAMILIN
GAG PR OTEOGLYCAN

65. FIBRES
• Mainly collagen fibre are type I and type III.
 These fibers form a loose, reticular network to
support other structural elements of the pulp.
 Collagen is synthesized and secreted by
odontoblasts and fibroblasts.
 In young pulp the fibers are relatively sparse
throughout the pulp and gradually the bundles
increase in size with advancing age.

66. Collagen fibres

67. GROUND SUBSTANCE
 The ground substances resembles that of other
loose connective tissue.
 It consists of acid mucopolysaccharides, neutral
glycoprotein and water.
 It acts as a medium for the transport of nutrients.

68. THE Pulp is a small tissue with
a big issue
I.B.Bender

69. VASCULATURE OF PULP
SAQIB HABIB / KHYBER COLLEGE OF DENTISTRY

70. BLOOD SUPPLY
• Extensive blood supply.
• Mainly supplied through inferior & superior alveolar
arteries.
• Entry through apical foramina
accompained by nerve bundles
• Rapid blood flow High blood
Pressure than rest of body

71. • Arterioles give off numerous
branches in the radicular
pulp ending in the coronal
pulp forming a extensive
capillary network.
• The plexus of capillaries is
located in sub odontoblastic
area(cell free area)
• The arterioles on entering
the pulp shows a reduction in
thickness of vessel wall
musculature and therefore
luman size increases.

72. • Rate of blood flow in the pulp of tooth is four
times the rate of blood flow in resting muscle
• Laser doppler flowmetry is device which
measures pulpal blood flow(pulp vitality)

73. BLOOD SUPPLY
Apical third
Middle third

74. INNERVATION
• Pulp has abundant nerve supply
which follows the distribution of
blood vessel through apical
foramina.
• Two types of nerve fibers are
present ;
– Sympathetic in nature; which
control the contraction of
smooth vessels of blood
vessels
– Sensory nerves; which are
maxillary and mandibular
divisions of trigeminal nerve.
• After entering the foramina they
form a network peripheraly and

75. Plexus of Rashkow
• The nerve fibers branch extensively beneath
the cell free zone to form the so called Plexus
Of Rashkow.
• In root no such plexus is present.
• Pulp horns are highly innervated than the rest
of the pulp
Plexus of Raschkow

76. • Sensory response in the pulp cannot
differentiate between heat,touch,pressure or
chemical stimuli.
• Pulp has only pain receptors.
A, Odontoblasts; B, Cell-free zone of Weil; C, Nerve plexus of Raschkow

78. The size of the pulp
The apical foramen
The cellular elements
Vasculature
Vitality,repairative power
decreased
AGE CHANGES
Reticular atrophy: a production of less vital pulp tissues and
less response to stimulation.

79. RETROGRESSIVE CHANGES
• Fibrosis
• Reduction in pulp chamber
• Neuro vascular changes
• Reduction in sensitivity
• calcification
• Decresed healing capacity
YOUNG OLD

80. PULP CALCIFICATION
• Calcification may occur as a result of increasing age
or external stimuli.These may be nodular masses
referred to as pulp stones or denticles
• Harmless until they compress nerve or vessel
PULP STONES
localized diffuse
TRUE
DENTICLES
FALSE
DENTICLES

81. TRUE DENTICLES
• Islands of dentine having dentinal tubules and
processes of odontoblast.
• Rare, small in size located near apical foramen
• They ere formed from the remnants of
Epithelial root sheath

82. FALSE DENTICLES
• Concentric calcified masses having no
dentinal tubules.
• Evidence of dystrophic calcification
• Overdosage of vitamin D may favour the
formation of denticles

83. • Pulp stones are classified as
free,attached or embedded
• Free denticle - entirely
suurounded bypulp tissue
• Attached denticle – Partly
fused with the dentin
• Embedded denticles –
Entirely surrounded by
dentine depending on their
relation to dentine.
FREE
ATTACHED

84. CLINICAL CONSIDERATIONS
• PULPITIS :
• Refers to the inflammation of dental pulp
within a
tooth
CAUSES:
Bacterial infection in dental caries.
Tooth fracture
Chemical irritants
Traumatic exposure

85. • REVERSIBLE PULPITIS ;
Condition affecting tooth accompained by short
lived pain
Heals with time by itself
• IRREVESIBLE PULPITIS ; Term referring to a
dead pulp or necrosed pulp.accopanied by
severe pain
Requires endodontic treatment.

86. ACCESSORY ROOT CANALS
• Accessory root canals are clinically significant
in the spread of infection to other tissues like
periodontal ligament,periapical tissues etc.

87. AERODONTALGIA
• Aerodontalgia got its name during WW II when
some pilots experienced toothaches while flying
high in unpressurized airplanes.
• They ultimately found that this was caused by a
decrease in atmospheric pressure as the planes
ascended to high altitudes.
• Any tiny pocket of air trapped during RCT or filling
resuts in air entrapment.

88. DURING OPERATIVE PRECEDURES
• Shape of the pulp chamber and its extensions into
the cusps pulpal horns is important.
• Wide pulp chamber into tooth of young person
will make a deep cavity preparation hazardous
• The pulpal horns project high into the cusps in
younger ages exposure of pulp can occur
• If opening a pulp chamber for treatment its size
and variation in shape must be taken into
consideration

89. FACTORS TO BE CONSIDERED DURING
ENTODONTIC TREATMENT
• Age advance , the pulp chamber becomes
smaller difficult to locate the root canals.
• Shape of the apical foramen and its location
may play an important part in treatment of root
canals.
• Accessory canals, and multiple canals are rarely
seen in roentgenograms.
• Dehydration causes pulpal damage operative
procedures producing this condition should be
avoided.

90. EFFECT OF DENTAL MATERIALS ON
PULP
• Filling material contain harmful chemicals
• Silicate cement - acid
• Composites – monomer
• GIC – Well tolerated by pulp
• Calcium hydroxide – dentin bridge formation.

91. CONCLUSION
• THE PRESEVATION OF A HEALTHY PULP
DURING
OPERATIVE PROCEDURES AND SUCCESSFUL
MANAGEMENT IN CASES OF DISEASES ARE TWO
OF MOST IMPORTANT CHALLENGE TO THE
CLINICAL DENTIST.

92. OFFICIAL SIGN OF DENTISTRY