Dentinal Pulp and Caries

Question 1

The dental pulp consists of loose connective tissue

derived from

Answer 1

neural crest (ectomesenchymal) cells

Question 2

Mature dental pulp is divided into two compartments:

Answer 2

Odontogenic Zone

Pulpal Core

Question 3

Odontogenic Zone (4)

Answer 3

• Odontoblast cell layer
• Cell-free zone of Weil
• Cell-rich zone
• Parietal plexus of nerves (Raschkow’s plexus)

Question 4

Pulpal Core (5)

Answer 4

• Fibroblasts
• Type I and III collagen
• Extracellular matrix
• Blood vessels
• Nerve tissue

Question 5

Functions of dental pulp: (4)

Answer 5

• Embryonic induction
• Formative
• Protective
• Reparative

Question 6

Cell populations in pulpal tissue include: (8)

Answer 6

  Odontoblasts 
  Fibroblasts 
  Undifferentiated mesenchymal cells 
  Macrophages 
  Dendritic cells 
  Blood vessel-related cells  (e.g., endothelial &      pericytes) 
  Neural-related cells  (e.g., Schwann cells) 
  Lymphocytes

Question 7

8% of total cell population (2)

Answer 7

 Macrophages

 Dendritic cells

Question 8

Extracellular matrix of pulpal tissues: (2)

Answer 8

 Collagen types I, III, IV, and V (via odontoblasts)

 Non-collagenous matrix components:

Question 9

 Non-collagenous matrix components: (5)

Answer 9

• Proteoglycans
• Glycosaminoglycans
• Phosphoproteins
• Glycoproteins
• γ- carboxyglutamate-containing proteins

Question 10

• γ- carboxyglutamate-containing proteins (4)

Answer 10

 BMP-2, 4, and 7
 Fibroblast Growth Factor (FGF)
 Epidermal Growth Factor (EGF)
 Dentin Matrix Protein (DMP)

Question 11

Pulpal innervation includes both

Answer 11

myelinated and

nonmyelinated nerve axons.

Question 12

Pulpal innervation includes both myelinated and
nonmyelinated nerve axons. They progressively
branch, passing through the

Answer 12

subodontoblastic layer
as the parietal neural plexus (Rashchow’s plexus), on
to the odontoblastic cell layer and some fibers enter
into dentinal tubules.

Question 13

Most nerve endings in pulp are for

Answer 13

pain (free nerve
endings as sensory afferents from C-V) with a few
concerned with vasodilatation or constriction.

Question 14

Sensory afferents from the Trigeminal (C-V): (4)

Answer 14

• Pain
• Mechanical (pressure)
• Thermal (heat)
• Tactile (touch)

Question 15

— branches from the superior
cervical ganglion are primarily vasomotor
fibers to pulpal blood vessels, concerned
for the most part, with —.

Answer 15

Sympathetic

vasoconstriction

Question 16

The majority of myelinated pulpal nerve axons are

Answer 16

A-δ (A-delta):
• Fast conducting
• Diameter in range of 1-6 μm

Question 17

1% of myelinated nerve fibers are classified as

Answer 17

A-β (A-beta) fibers:

• 6-12 μm diameter

Question 18

Nonmyelinated fibers are designated as

Answer 18

“C” fibers and have small diameters, ranging from 0.4 to 1.2 μm

Question 19

A-δ fibers are associated with

Answer 19

sharp, localized pain.

Question 20

“C” fibers are associated with

Answer 20

dull, diffuse pain.

Question 21

Neuropeptides and neurotransmitters identified in

dental pulp include: (6)

Answer 21

  Calcitonin gene-related peptide (CGRP)
  Substance P 
  Epinephrine 
  Norepinephrine 
  Dopamine 
  Endorphin

Question 22

Calcitonin gene-related peptide (CGRP)

Answer 22

• Vasodilatation, stimulates fibroblast cell division

Question 23

Substance P

Answer 23

• Vasodilatation, stimulates fibroblast cell division

Question 24

Epinephrine

Answer 24

• Vasoconstrictive via arteriole smooth muscles

Question 25

Norepinephrine

Answer 25

• Sympathetic vasoconstrictor

Question 26

Dopamine

Answer 26

• Vasoactive or a precursor of epinephrine

Question 27

Endorphin

Answer 27

• silencer of nociceptors (silencer of pain)

Question 28

Each fiber contributes at least

Answer 28

8 branches to
Raschkow’s plexus. Most terminate in the
plexus as free, nonmyelinated nerve endings.

Question 29

Location: pulp horns
Predentin:
Mineralizing Front:
Denton up to 100 um:

Answer 29

27%
11%
8%

Question 30

Location: remaining crown
Predentin:
Mineralizing Front:
Denton up to 100 um:

Answer 30

14%
6%
2%

Question 31

Location: root
Predentin:
Mineralizing Front:
Denton up to 100 um:

Answer 31

11%
0%
0%

Question 32

Venules have a diameter of

Answer 32

100 um to 150 um

Question 33

Arterioles have a diameter of

Answer 33

50 um to 100 um

Question 34

The terminal capillaries anastomose deep to the — layer

Answer 34

odontoblastic

Question 35

Capillary loops are dense in the coronal and pulp horns

and significantly less dense in the

Answer 35

radicular pulp

Question 36

(2) capillaries and lymph vessels

are found in pulp

Answer 36

Continuous and fenestrated

Question 37

With aging, blood vessels in pulp will exhibit changes such
as

Answer 37

cholesterol plaques (atherosclerosis). If progressive
and severe, atherosclerotic plaques can result in pulpal
hypoxia due to vessel strangulation.

Question 38

Fenestrated capillaries leak serum that becomes a component of the
so-called “— —”. They also contribute to

Answer 38

tissue fluid

swelling and edema due to significant leakage of serum in states of inflammation.

Question 39

Pulpal fibrosis occurs with

Answer 39

increasing age or persistent 
low-grade injury, e.g., multiple 
restorations in a single tooth, 
chronic bruxism, repeated 
thermal insult, etc.

Question 40

Diffuse Calcifications:

Answer 40

Irregular calcified deposits along
collagen fiber bundles or within blood vessels resulting
from chronic low-grade inflammation.

Question 41

Pulp Stones (a.k.a. Denticles):

Answer 41

True pulp stones contain
dentinal tubules. False pulp stones feature concentric layers of
calcified tissue but are void of dentinal tubules.

Question 42

Pulp Stones are classified as either (3)

Answer 42

free, attached or embedded

Question 43

An abscess is defined as a

Answer 43

dense aggregation of
neutrophils and macrophages and other inflammatory
cells within connective tissue undergoing liquefactive
necrosis.

Question 44

Due to the inability of pulpal tissue to swell, the
increasing edema and inflammatory cell infiltration
will eventually lead to

Answer 44

pulpal necrosis that, in turn, is
expressed clinically by persistent pain and periapical
necrosis of the PDL and associated alveolar bone.

Question 45

The periapical necrosis is seen on dental radiographs

as a

Answer 45

radiolucent area associated with the apex of the

involved tooth.