Dental Pulp (WRIGHT)

What are the 4 zones of the of the dental pulp?

Odontoblastic Zone- Outermost. Where the odontoblasts are

Cell Free Zone of Weil

Cell Rich Zone

Pulp Core- Majority of pulp

What is the odontogenic zone of dental pulp?

This is the region of the pulp that contains the:

-Odontoblastic zone

-Cell Free zone of Weil

-Cell Rich Zone

What is the primary cell type of dental pulp?

Fibroblasts

What is the cell shape of odontoblasts?

Columnar

What cell type makes up the cell rich zone of the pulp?

Fibroblasts

What is the purpose of undifferentiated ectomosenchyme cells in dental pulp?

Gives rise to odontoblasts, fibroblasts, and other cell types.

Where are dendritic cells found in the dental pulp?

Near the odontoblast layer.

What type of collagen is found in the pulp matrix?

Type I and III

Where in the root are collagen fibers most dense?

Densest near the apex

What arteries innervate the dental pulp?

Superior and Inferior alveolar artery

Where are the capillary beds located within the pulp cavity?

Sit in the subodontoblastic region and extends through the odontoblast layer into the pre-dentin

Where do larger arteries and nerve branch in the pulp cavity?

Branch centrally

What is the subodontoblastic/parietal plexus of Raschkow?

A collection of nerve fibers found in the walls of the pulp chamber in the cell-free zone. These fibers will enter dentinal tubules and travel alongside odontoblast processes.

-Only found in thr crown

Where do the nerve of dental pulp originate from?

-Afferent fibers of cranial nerve V

-Post ganglionic sympathetic fibers of the superior cervical ganglion

Why is the localization of pulpal pain difficult?

Convergence of multiple pulpal afferent fibers with afferent fibers of orofacial structures makes it difficult.

What are the senses that pulpal afferent fibers can detect?

-Mechanical

-Thermal

-Tactile

-Pain

What are considered the painful stimuli of dental pulp?

Temperature- Cold air/water

Mechanical- Burs and Probes

Dehydration- Cotton and air

What is the most supported theory of dentin sensitivity?

Hydrodynamic theory

What are the three theories of what causes dentin sensitivity/pain?

1. Directly stimulating nerve endings

2. Odontoblast processes act as pain receptors and couple with the pulp nerves

3. Movement of the fluid in dentinal tubules causes pain detection in the plexus of Raschkow

What are pulp stones?

Calcified masses that have calcium and phosphate ratio similar to dentin.

Where are pulp stones usually located?

At the orfices/opening into the root or within the root canal.

What do pulp stones form concentric rings around?

-Blood Thrombi

-Dead Cells

-Collagen fibers

What are true pulp stones?

These are pulp stones that resemble dentin and have tubules which are surrounded by odontoblast-like cells

Where are true pulp stones most commonly found?

Near the apex of the root.

What are false pulp stones?

These are pulp stones that have no cells or tubules associated with them.

-Concentric layers of mineralized tissue

What are the 3 orientations of pulp stones within the pulp?

Attached- Stone is attached to the dentin wall

Free- Stone is completely embedded in the pulp cavity

Embedded- Stone has become entrapped in the dentin wall.

What is the clinical significance of pulp stones?

-Can decrease the overall number of cells found in the pulp

-Can impede the debridement during endodontic treatment

Dystrophic calcification

Regions of the pulp cavity that becomes calcified. Increases with age.

What happenes to dentinal tubule diameter as a person ages?

Decreases in diameter

What happens to axon activity within the pulp of teeth as we age?

Axon activity decreases which leads to reduced tooth sensitivity

What happens to the number of pulp cells as we age?

The number of pulp cells decrease signficantly as we age.