Dental pulp Flashcards
(33 cards)
What is the dental pulp
Soft connective tissue contained within the pulp chamber and the root canals of the tooth
Where is the coronal pulp found
Pulp chamber
Where is the radicular pulp found
Root canals of the tooth
What are the functions of the dental pulp
- Involved in the production of primary and secondary dentine
- Responsible for sensory function of the pulp-dentine complex
- Supplies essential nutrients for dentine formation
What are the 4 zones of the dental pulp
- Odontoblast Layer
- Cell free zone of Weil
- Cell rich zone
- Deep pulp cavity
Describe the odontoblast layer
Comprised of a single layer of cell
What can be found in the cell free zone of weil
- Fibroblast process
- Odontoblast process
- Nerve axons
- Capillaries
Describe the cell-rich zone
- High cell density
- High concentration of capillaries and axons
How much water and organic material is present, by %
Water - 75%
Organic material - 25%
How does the overall collagen content differ with age
As age increases, the overall collagen content in the pulp increases
What is the fibrous component of the dental pulp a combination of
Collagen Type I and Collagen Type III grouped into fibres, thinly and irregularly scattered into tissue
What are Glycosaminoglycans?
What do they do within the pulp?
- Unbranched polysaccharide chains
- Hydrophilic so when in combination with water, they give the pulp its unique gel-like properties
- This means it can swell, fill most of the extracellular space and stabilize the position of cellular components
Describe the role of fibroblasts
- During tissue development, they produce extracellular fibres and ground substance
- Ingest and degrade collagen
- In the mature tooth, they slowly produce and turnover the extracellular matrix
Describe the role of odontoblasts
- Form a single layer of cells attached to the predentine surface
- Acts as a control barrier between dentine and the pulp
Where are the dental pulp stem cells found and what do they do
- Found beneath the odontoblast layer & more centrally around blood vessels
- Differentiate into odontoblasts, neurons…
Describe macrophages in the dental pulp
Involved in the elimination of dead cells
Describe T lymphocytes in the dental pulp in terms of numbers
Present in small numbers, however this increases when pulp is injured or subjected to toxins
Where are the antigen-presenting dendritic cells found and what do they do
- Found beneath the odontoblast layer & around nerves and blood vessels
- They’re bone marrow derived
- Participate in immunosurveillance
- Act as antigen-presenting cells
What are the blood vessels within the dental pulp?
State where they’re located
- Arterioles and venules - enter pulp via apical foramina as components of neurovascular bundles
- Capillary network - Beneath the odontoblasts, is called the subodontoblastic capillary plexus
- Terminal capillary loops extend to lie between odontoblasts in the odontoblast layer or between odontoblasts and the predentine
- Arteriovenous anastomoses - between peripheral pulpal vessels to allow rapid changes in blood perfusion
What are the 2 different types of nerve bundles?
What type of axons does each bundle contain
- Sensory afferent nerves of the trigeminal nerve
- Sympathetic efferent branches from the superior cervical ganglion
- Myelinated and unmyelinated axons
What do most myelinated axons terminate as
They terminate as free unmyelinated nerve endings, in an extensive plexus of nerves beneath the cell-rich zone
How do a small number of unmyelinated nerve endings exit
- They exit the plexus and travel up to and terminate around the odontoblasts.
- A subset of these will continue into the dentinal tubules along with the odontoblast processes
What are the 2 main types of sensory nerve fibres in the pulp
- myelinated A-fibres
- unmyelinated C-fibres
Describe the myelinated A-fibres
- Most terminate at the sub-odontoblast, odontoblast and predentine/dentinal tubules
- Thought to be responsible for the rapid, sharp-pain sensation commonly associated with dentine hypersensitivity
