1. The pulp contains cells, blood vessels, nerves, and connective tissue that provide nutrition and defense for the tooth. 2. The odontoblasts in the pulp are responsible for forming dentin throughout life in response to stimuli. They also help maintain the dentin-pulp complex by regulating fluid flow within the dentinal tubules. 3. The main functions of the pulp are induction of dentin formation, nutrition of the tooth, defense against irritants, sensation, and maintenance of the dentin. Damage or death of the pulp can occur when there is no drainage of fluid or limited access for repair.

1. Pulp Biology
Teaching Assistant Dr. Mohd Aldawla
Department of Conservative Dentistry, Faculty of Dentistry
Lec. 2

16. Pulpo-dentinal Complex

17. Odontoblastic process & A-delta
fibers
- Why dentin is sensitive ..

18. - Intrapulpal pressure …
GENTLE outward fluid flow
inside DT. This Flushing
mechanism keep the DT
clean and decrease MO
penetration.
- Rapid outward flow cause
sharp pain, that is why if
you run dental explorer
over live dentin the patient
will actually have sensation
of pain.
outward fluid flow
GENTLE

19. Dt has a conical shape… the
closer the DT to the pulp, the
larger it’s diameter become
What dose this
mean clinically
?????

20. Dentin Sensitivity: Three Theories
1. Nerve in dentin: The dentin
contains nerve endings that
respond when it is stimulated.
2. Odontoblastic process: The
odontoblasts serve as receptors and
are coupled to nerves in the pulp.
3. Fluid movements in the dentinal
tubules (Hydrodynamics): The
tubular nature of dentin permits
fluid movement to occur within the
tubule when a stimulus is applied –
a movement registered by pulpal
free nerve endings close to the
dentin.
1
2
3

21. Contents of the pulp
 Cells: Odontoblast (around the periphery to maintain and
repair dentin), Fibroblast (In the pulp core supporting a
network of vascular and nerve cells), White-blood cells,
Undifferentiated mesenchymal cells, Macrophages and
Lymphocytes.
 Fibrous Matrix: Mostly reticular fibres and collagen fibres
(Type I and Type III).
 Ground substance: Act as a medium to transport
nutrients to cells and metabolites of the cell to the blood
vessels..

22. Neurovascular Components
 The pulp contains the nerve and blood
supply to the tooth
Vascular System
 Thy are branches of the
inferior alveolar artery, the
superior posterior alveolar
artery, or the infraorbital
artery.

23. Lymphatics
• Lymphatic vessels arise as small, thin-
walled vessels in the periphery of the
pulp.
• The lymphatics assist in the removal of
inflammatory exudates and cellular debris.
• After exiting from the pulp, some vessels
join similar vessels from the PDL and
drain into regional lymph glands
(submental, submandibular, or cervical)
before emptying into the subclavian and
internal jugular veins.
An understanding of lymphatic drainage assists
in the diagnosis of infection of endodontic
origin.

25. Innervation
 Second (maxillary) and Third
(mandibular) branches of the
trigeminal nerve.
 Mylohyoid nerve (sensory branches)
possible auxiliary innervation for
mandibular premolars
 2nd & 3rd cervical spinal nerve possible
auxiliary innervation for mandibular
molars. This can create difficulties
in anesthetizing these teeth with
an inferior dental block injection
only.
Afferent Neurons

29. nociception

30. nociception
proprioception

31. nociception
proprioception

32. nociception
proprioception
What dose this
mean clinically
?????

35. -COLD
-DENTINAL
-EPT

36. -COLD
-DENTINAL
-EPT
HEAT

37. -COLD
-DENTINAL
-EPT
HEAT
What dose this
mean clinically
?????

38. Primary Functions of the Pulp
1. Induction
Pulp participates in the
initiation & development
of dentin.
• When dentin is
formed, it leads to
the formation of
enamel.

39. 2. Formation
Odontoblasts form dentin
• These highly specialized cells participate in dentin formation in three ways:
1. Synthesize and secrete inorganic matrix
2. Transport inorganic components
3. Create environment for mineralization
 Early tooth development Primary Dentin Formation rapid and
symmetric pattern.
 After tooth maturation Secondary Dentin Formation slow and less
symmetric pattern.
 Response to caries, trauma, or restorative procedures Tertiary Dentin
Formation.
Primary Functions of the Pulp

40. Primary Functions of the Pulp
Tertiary dentin has two forms:
 Reactionary tertiary dentin is formed by the original odontoblasts

41. Primary Functions of the Pulp
Tertiary dentin has two forms:
 Reparative dentin is formed by new odontoblasts differentiated from stem
cells after the original odontoblasts have been killed.

42. 1. Nutrition
The pulp supplies nutrients
that are essential for dentin
formation and for
maintaining the vitality of
its cellular constituents by
providing oxygen and
nutrients sufficient for their
metabolic requirements
Secondary Functions of the Pulp

43. Maintenance of Dentine (fluid environment).

44. 2. Defense
 Odontoblasts form dentin in response to
injury and caries
 Dentin can also be formed at sites where its
continuity has been lost, such as at a site of
pulp exposure.
 Pulp also has the ability to process and
identify foreign substances, such as the
toxins produced by bacteria of dental
caries, and to elicit an immune response
to their presence.
Secondary Functions of the Pulp

45. 3. Sensory
It responds to irritation
by producing patterns of
neural activity giving
rise to painful sensations
Secondary Functions of the Pulp

46. 4. Esthetic

48. Stimuli
• Air
• Cold
• Heat
• Carbohydrates
• Mechanical

50. Why Does The Pulp Die?
A. No drainage within the pulp (fluid can only
move through rest of pulp).
B. Terminal circulation
C. Limited access for repair (from apical direction
only).
D. Pulp is surrounded in three dimensions (by
hard tissue).
E. Stimulus is concentrated in the pulp (diffusion
through tubules from large area and
concentrated on small tissue).
F. Limitations of dental materials available for
treatment.

51. Thank you