(5) pulp Flashcards
Where is the pulp located?
contained within the pulp chamber and the root canals.
Apical, what does the pulp become continuous with?
Periodontal ligament
Why can’t you see the apical foremen?
It has been cut so you cannot see it
What lines the border of the pulp and dentin?
odontoblasts
What is the pulp?
connective tissue
What does the pulp contain?
nerves fibres and blood vessels
Antigen presenting cells
Where are odontoblasts bigger?
At the crown end
Where are the accessory canals located?
Apical third of root
What is the main component of the dental pulp?
collagen
What is the organisation of the collagen type 1 fibres?
Fibrils thinly scattered through the pulp.
* Randomly organized.
What is the organisation of collagen type 1 fibres at the peripherals ?
the peripheries, they area parallel to the predentine surface.
When are collagen type 1 fibres parallel and right angled to peripherals?
- At the peripheries, they area parallel to the predentine surface.
- Right angles to the amelo-dentine junction in mantle dentine (von Korff’s).
What collagen fibre is found in large amounts?
type 3
Do type 1 and 3 collagen fibres have a similar organisation?
Similar banding pattern as type I.
What fibres are present in the pulp but at smaller level?
Collagen type V : present in small amounts. * Collagen type VI: present in small amounts. *
Fibrillin:
* Microfibrils smaller in diameter than collagen.
* Large glycoprotein.
What are the components of the non-fibrous matrix?
Glycosaminoglycans.
* Proteoglycans
* Other adhesion molecules.
What cells are present in the pulp?
- Odontoblasts.
- Fibroblasts.
- Immune cells.
- Undifferentiated cells.
What cells are shown here?
Odontoblasts
What shape do the fully differentiated odontoblasts take?
- A fully differentiated odontoblast is a polarized columnar cell with a long process inside a tubule.
What links adjacent odontoblasts and other pulp cells?
Small processes
Is the pulpal odontoblasts a single cell layer?
Yes
How do the odontoblasts attach to the predentin?
Odontoblasts form a layer of single cells attached to the predentine by a single process.
Is the pulp highly innervated?
Yes
What is the shape of odontoblasts at the root vs coronally?
Coronal odontoblasts are columnar in outline, while they are almost cuboidal in the root.
How do odontoblasts appear in oblique sections?
Pseudo-stratified
Name structures A-C
What do fibroblasts do?
- They slowly produce fibres and ground substance.
- Pulp fibroblasts can degrade
extracellular matrix, matrix turnover
Apoptosis
What do fibroblasts produce?
Production of growth factors and cytokines.
What are examples of immune cells in the pulp?
- T-lymphocytes
- Macrophages
- Dendritic antigen presenting cells
What cells lie under the odontoblastic layer?
Cells layer capable of differentiating into odontoblasts.
What are examples of cells capable of differentiating into odontoblasts?
- Pluripotent primitive mesenchymal cells that could differentiate into a variety of cell types.
- Modifying cell activity by a change in gene expression.
- Modified fibroblasts???
What blood vessels associate with the pulp?
Arterioles and venules
How do the arteriolar and venues enter the pulp?
enter the pulp via the apical foramen and lateral canals.
Do the venues and arteriolar have branches?
Yes, to reach peripherals
Where do the blood vessels branch profusely?
once within the coronal pulp chamber.
Where do the odontoblast lie in the pulp?
Periphery
What is the composition of water and organic material in the pulp?
75% water
25% organic material
What is the main component of pulp?
Collagen type 1
How is the collagen type 1 organised?
Randomly
What is the orientation of collagen at the peripherals of the pulp?
They are parallel to the predentine surface
What is the orientation of collagen type 1 fibres at the amelo-dentin junction in mantle dentine?
Right angles
Called Von Korff’s fibres
What is the precursor of collagen fibres?
Alpha chain
What composed procollagen?
3 alpha chains of collagen
How does procollagen become collagen molecule?
Procollagen peptides
What does a single collagen molecule form?
Collagen fibril after assembly
What is the second most abundant collagen fibre in the pulp?
Collagen type 2
What is similar between collagen 1 and 2?
The banding
What percent of total pulpal collagen is type 2?
41%
What are the least abundant types of collagen in the pulp?
Type V and VI
Name the fibres found in the pulp?
Collagen 1, 2, 5, 6
Fibrillin:
Microfibrils
Large glycoproteins
What are the types of fibrillins found in the pulp?
Microfibrils
Large glycoproteins
What are the 2 types f adhesion molecules in the pulp?
Lamin and fibronectin
What occurs here?
Mineralisation front
How do odontoblasts attach to one another?
Different types of cell junctions
What are 3 types of cell junctions?
Desmosomes
Tight junctions
Gap junctions
What is the role of desmosomes?
Mechanical union
What is the role of tight junctions?
Limit permeability, mechanical integrity
What is the role of gap junctions?
Synchronisation
What can pulp fibroblasts degrade?
Extracellular matrix
What do fibroblasts turnover?
Matrix
