18. Dentine-Pulp Complex Flashcards
Define ‘dental pulp’
connective tissue derived from mesenchymal cells of dental papilla
2 types of dental pulp
- coronal pulp
- radicular pulp
Apical foramen and accessory canals are entry for …
- blood vessels for nourishment
- nerves for sensation
- lymphatic vessels for lymph drainage
Dental pulp is … connective tissue made of …
- loose
- extracellular matrix
- diff cell types
- blood and lymphatic vessels
- nerves
Dental pulp is …% water and …% organic material
Does this ever change?
- 75, 25
- changes in development (dental papilla to dental pulp) and varies between tooth types
Is there hard tissue in dental pulp?
- none in normal pulp
- calcifications and pulp stones occur in aged teeth
How different is pulp structure in primary and permanent teeth?
similar
- 4 zones in each
4 histological zones in pulp
- odontoblast cell layer
- cell-free zone
- cell-rich zone
- pulp core
Odontoblast cell layer contain what kind of cell?
- odontoblasts
What’s within the cell-free zone?
- few cells
- mainly extracellular matrix
- nerve endings
What’s within the cell rich zone?
many cells
- mainly fibroblasts
What’s within the pulp core?
- central tissue
- nerves
- blood vessels
From innermost of pulp to outermost, order the layers
- cell rich zone
- cell free zone
- odontoblast layer
- predentin
- mineralization layer
Cells within pulp
- odontoblasts
- fibroblasts
- undifferentiated mesenchymal cells
- stem cells
- defence cells
Coronal odontoblasts are … and have what features?
- columnar
- cellular process into dentinal tubule
- more cuboidal in root
Odontoblasts produce what? and for how long?
- dentine (predentine)
- present throughout life of tooth
As the tooth matures, what happens to odontoblast layer of pulp?
- becomes flatter
- number of cells reduced by apoptosis
- secondary dentine laid at slow rate
- reduces size of pulp
How does the odontoblast layer of pulp respond to external stimuli?
- odontoblast-like cells can differentiate from progenitor cells in pulp
- produces tertiary dentine
3 types of junctions between odontoblasts
- tight
- desmosomes
- gap
Role of tight junctions and desmosomes in odontoblasts
- maintains spacial relationships
- restricts substances in pulp from entering dentine
Role of gap junctions in odontoblasts
- openings allow exchange of small molecules and cell-to-cell communications
What is the most abundant cell type in dental pulp?
fibroblasts