Pulp

Question 1

Apical foramen size

Answer 1

.3 to .6mm

Question 2

Odontogenic zone

And zone of weil

Answer 2

• it’s the odontoblastic + cfz +crz

- it’s the cell free zone

Question 3

Cfz

Answer 3

Less prominent in root

Question 4

Pulp outline follows the ….

Answer 4

Outer Dentin outline

Question 5

Pulp organ definition

Answer 5

After dentin

production begins, It is now called the pulp organ.

Question 6

Stages of fibroblast

Answer 6

Large multiple processes with Central nucleus, numerous synthetic organelles if young pulp.
• In aged pulp: appear smaller, flattened, spindle shaped with few organelles and termed FIBROCYTES.
• During degradation they have cytoplasmic granules and lysosomes and termed FIBROCLASTS.

Question 7

Location of fibroblast

Answer 7

Loose network all over the pulp and more in crz

Question 8

Junction between fibroblast?

Answer 8

At the processes junctions to processes of other fibroblasts.

Question 9

Histiocytes

Answer 9

Definition: They are tissue-resident macrophages found in connective tissue.
➢ Function: • involved in elimination of dead cells during the turnover of dental pulp
•Remove bacteria and foreign bodies •Have immune roles during inflammation
➢ Site: located in the pulp center around blood vessels and capillaries. ➢ Microscopic picture: • Irregular in shape with short blunt processes and invagination of plasma membrane, small dark nucleus and granular cytoplasm.
• The distinguishing feature is aggregation of vesicles or PHAGOSOMES which contain phagocytosed dense irregular

Question 10

Plasma cell

Answer 10

Microscopic picture: • Nucleus appears small and eccentric in the cytoplasm,
• The chromatin of nucleus is adherent to nuclear membrane and so give the cell the characteristic CART-WHEEL appearance.

Function: They are more seen during inflammation and their function is to produce antibodies.

Question 11

Mast cell

Answer 11

Function: Their number increase during inflammation and they produce histamine & heparin.
• Microscopic picture: • They have a round nucleus and their cytoplasm contains many GRANULES.
• They are demonstrated by using special stains as TOLUIDINE BLUE.

Question 12

Dendritic cells

Answer 12

Site: distributed largely around odontoblasts and central blood vessels.
• Microscopic picture : they have three or more main dendritic processes which branch.
• Function: they act as ANTIGEN PRESENTING CELLS stimulating the division and activity of native Tlymphocytes.

Question 13

Other leukocytes

Answer 13

They are blood vascular elements that are found extravascularly in normal pulp
• Examples: neutrophils, eosinophils, basophils, and lymphocytes.
• Function: during inflammation they increase in number.
• In normal pulp T-lymphocytes are more present than B-lymphocytes.

Question 14

تجميع للsites of pulp cells

Answer 14

• fb—crz and allover pulp
• stem— crz and pulp center around bv
• histiocytes — in center around bv and capillaries
• dendritic— center around bv and around odontoblasts

Question 15

UMC

Answer 15

Function: • They represent the pool fromwhich the cells of the pulp are derived. • When need arises they may become odontoblasts or fibroblasts.
• Number: They are the primary cells in the very young pulp but decrease after root completion and in older pulp.
• Site: they are found in cell rich zone and pulp core and around blood vessels. • Microscopic picture: large, polyhedral in shape with peripheral cytoplasmic extensions, when side-viewed they appear SPINDLE-shaped.
• Mesenchymal Stem cells can be isolated from the pulp like: Dental pulp stem cells (DPSC) & stem cells from exfoliated deciduous teeth (SHED).

Question 16

Change in pulp collagen with age

Answer 16

In young pulp: single fibrils of collagen are found scattered between the pulp cells.
• With age: the collagen content becomes organized into fiber bundles especially in the most APICAL PORTION of the pulp.

Question 17

Why engage the pulp apically

Answer 17

Clinical tip: During endodontic ttt it’s better to engage the pulp at the apical region rather than coronal to prevent tissue tearing.

Question 18

Is there elastic fibers in the pulp

Answer 18

Only in wall of large blood vessels

Question 19

Chondroitin and hyaluronic acid in pulp?

Answer 19

During early development, chondroitin A&B and hyaluronic acid has been demonstrated in abundance.

Question 20

Pulpal blood flow

Answer 20

is more rapid with higher blood pressure than in most areas of the body.

Question 21

Arterial plexus in pulp is

Answer 21

Sub odontoblastic parietal capillary plexus

Question 22

Lymphatic of pulp special stain and shape

Answer 22

Lymph vessels are best examined by Iron hematoxylin stain. • Branched vessels appear as H, Y or I shaped.

Question 23

Relation between lymphatic of pulp and pdl

Answer 23

Lymph vessels draining the pulp & periodontal ligament have a common outlet.

Question 24

Nerves in the pulp
Type
Arrangements 
Stain
Time of development 
Most found in ...

Answer 24

As the myelinated nerves run longitudinally, they give off side branches as free nerve endings that terminate in a subodontoblastic plexus known as PLEXUS OF RASHKOW or PARIETAL LAYER OF NERVES.
•This plexus is more prominent under pulp horns. • It is not evident until the tooth has erupted. •A small numbers of nerve fibers lose their Schwann cell coating and pass between the odontoblast cell bodies and dentinal tubules. •Silver stain is used to demonstrate nerve fibers.

Pulp is richly innervated (What nerves?) • Nerves enter the pulp through apical foramen along with afferent blood vessels and together form neurovascular bundle.
• Two types of nerve fibers are present: 1. Non myelinated sympathetic nerves that supply large muscular blood vessels to function in contraction or dilatation of blood vessels.
2. Myelinated sensory nerves of trigeminal nerve which can not differentiate between heat, touch, pressure or chemicals. This is because the pulp has only PAIN RECEPTORS (NOCICEPTORS).

Question 25

Clinical consideration of the pulp

Answer 25

Q1) Dental Pain is diffuse while periapical pain is localized?
Due to absence of MECHANORECEPTORS
Q2) Can dental pain be referred to the opposite side?
No, pain may be referred to the same side only but doesn’t cross the midline

Clinical tip: During endodontic ttt it’s better to engage the pulp at the apical region rather than coronal to prevent tissue tearing.

Clinical tip: Accessory canals may be a source of transinfection between pulpal and periodontal tissues causing periodontic-endodontic lesions.

Clinical tip: Knowledge of anatomy of pulp chamber and horn locations is essential in operative dentistry to avoid pulp exposure especially in young age

Q1) Sometimes, in irreversible pulpitis , hot drinks aggrevate the pain while cold drinks may relief it?
Because heat causes expansion of gases and blood vessels while cold causes contraction.

On lying down, dental pain increases? pulpal blood pressure and pressure on nerves increases as well.

Sequelae of pulp infection

Orthodontic forces may cause damage and inflammation to the pulp.

Pulp tests like …..and Teeth may have damaged nerves (no and response to sensitivity tests) BUT normal blood supply so it is completely viable (e.x. traumatized teeth)

Pulp capping

Question 26

Age changes of pulp

Answer 26

-Vascularity: vascular supply decreases with calcification in blood vessels walls (atherosclerosis)
-Size: ❖Size of pulp chamber, horns & root canal decreases or becomes completely obliterated.
❖The apical foramen is narrowed. ❖This may cause reduction in the vascular supply of the pulp.

Sensitivity: Loss & degeneration of myelinated &non myelinated axons …… reduction in sensitivity.

Fibrosis of pulp
❖Collagen synthesis and degradation rates are diminished.
❖Fibrils become arranged as bundles
❖With decreased cell number and pulp size …pulp looks apparently more fibrous.

Cellularity: cells decrease in activity & number especially progenitor cells leading to reduced reparative functions

Question 27

Diffuse pulp calcification

Answer 27

They are irregular calcific deposits in pulp tissue. ❖ Site: Commonly occurring on top of hyaline degeneration in the root canal and not common in pulp chamber.
❖ Structure: ❖ Mostly fine, amorphous calcified spicules with no specific structure
❖ They follow the course of blood vessels or collagen bundles or as dystrophic calcification.

Question 28

Diff in location of diffuse and localised calcification

Answer 28

Diffuse —-root

Localized—-root or crown

Question 29

Diff between true and false pulp stone

Answer 29

-true
..apical
..small
..dentinal tubules and odontoblasts
..less common
.. Remnants of epithelial root sheath of Hertwig invade pulp tissue leading to differentiation of UDMCs of pulp to odontoblasts forming irregular masses of dentin

• false
  Degenerated cells, areas of hemorrhage or thrombi act as central nidus favoring deposition of concentric layers