Pulp Flashcards
What is dental pulp
- The specialized soft connective tissue of the tooth
* Occupies the pulp chamber and root canal(s)
What is the role of the dental pulp
- Active throughout life and maintains health of dentine through odontoblast layer
- Functionally and structurally associated to dentine
- Provides sensation (nerve endings) and blood supply (nutrients and immune cells)
What is the coronal pulp
occupies the crown of the tooth and has six surfaces; occlusal, mesial, distal, buccal, lingual and the floor.
What is the radicular pulp
extends from the cervix down to the apex of the tooth. Molars and premolars exhibit multiple radicular pulps. This pulp is tapered and conical
Where can odontoblasts be found in the dentin
right next to the pulp, innermost section of the dentin layer
What do the fibroblasts in the pulp do
Demonstrates the ability to degrade collagen as well as form it
What is the role of perivascular cells in the pulp
Undifferentiated mesenchymal cells, they’re present in the pulp and can give rise to odontoblasts, fibroblasts or macrophages
What is the zone of weil in the pulp
Its a cell-free zone that consists of nerves and capillary plexuses
What are the microscopic zones of the pulp
Odontoblastic layer
Cell-free zone
Cell-rich zone (more cells and vascularity)
Pulpal core (more cells and vascularity)
What is the role of odontoblasts in the pulp
Contributes to the protection of the pulp
BTW - the processes of odontoblasts still extend into the dentin tubules from the pulp
What are some inflammatory cells in the pulp
T lymphocytes
Macrophages
Dendritic antigen presenting cells
Where are macrophages found in the pulp
Found predominantly around central blood vessels and
adjacent to odontoblast layer
Where are dendritic antigen presenting cells found in the dentin
Similar distribution to macrophages, but also may be found between odontoblasts and dentine
What is the bottom point of the roots where the pulp enters through called
the apical foramen
Describe how the vascular supply ascends to the pulp
- small arterioles enter the pulp via the apical foramen
- ascend through the radicular pulp of the root canal
- branch out peripherally to form a dense capillary network immediately under and sometimes extending up into the odontoblast layer
- Small venules drain the capillary bed and eventually leave as veins via the apical foramen.
Why are pulpal vessel walls allowed to be very thin
As the pulp is protected by a hard unyielding sheath of dentin.
Why do the capillaries in the pulp exhibit numerous pores
the high metabolic activity of the odontoblast layer
Is blood flow/pressure quite high or low in the pulp
Quite high
What are arteriolar-venous anastomoses
Points that are frequent in the pulp where the arteries and vein vessels connect and overlap
What autonomic fibres are found in the pulp
Only sympathetic fibres
Describe the features of the sympathetic fibres, include where they originate
- fibres extend from the neurons whose cell bodies are found in the superior cervical ganglion at the base of the skull
- They are unmyelinated fibres
- Travel with the blood vessels.
What do the sympathetic fibres in the pulp do
They innervate the smooth muscle cells of the arterioles and therefore function in regulation of blood flow in the capillary
What afferent (sensory) fibres are found in the pulp and where do they terminate
- maxillary and mandibular branches of the fifth cranial nerve
- terminate in the central pulp
What is the subodontoblastic plexus
Small individual fibres from the afferent fibres that form this plexus just under the odontoblast layer, these terminate as free nerve endings near the odontoblasts.
Where is the subodontoblastic plexus mainly found
The subodontoblastic plexus is primarily located in the roof and lateral walls of the coronal pulp. It is less developed in the root canals.
What are the functions of the dental pulp
A living pulp is required to maintain dentine integrity and tooth sensitivity
- The primary function is providing vitality to the tooth.
- inductive
- protective
What is the inductive function of the pulp
very early in development the future pulp interacts with surrounding tissues and initiates tooth formation.
Describe the protective function of the pulp
pulp responds to stimuli like heat, cold, pressure, operative cutting procedures of the dentin, caries, formation of sclerotic and reactive dentin
What does inflammation of the pulp due to caries cause
high fluid content and swelling: compression of nerve fibres on the walls of the pulp cavity and pain
What happens to the pulp with age
• less cellular
• more fibrous
• overall reduction in volume due to the continued
deposition of dentin (secondary/reactive)
