L5: Dentine-Pulp Complex Flashcards
what common ancestry do dentine and pulp share?
dental papilla
what collagen types are present in dentine and pulp?
dentine: I
pulp: I, II, V
does peripheral dentine have type IV collagen?
what is type IV collagen?
No,
basement membrane
what type of dentinogenesis do existing odontoblast cells stimulate?
reactionary dentinogenesis
what type of dentinogenesis requires progenitor cells from the pulpal tissues in order to be stimulated?
reparative dentinogenesis
what is mantle dentine?
the first layer of dentine
what is mantle dentine layed down by?
odontoblasts
when is primary dentine formed?
it is formed by odontoblasts during the development of the tooth
when is secondary dentine deposited?
slowly throughout the life of the tooth
when is teritary dentine laid down?
rapidly on the pulpal aspect when there is occlusal wear/disease
where is dentinal fluid derived from?
pulpal extracellular fluid
What is the function of Dentin phosphoprotein (phosphophoryn) in mineralised dentine?
Modulates remineralisation
How is dentine and pulp related?
They are functionally coupled and integrated as a united tissue
What is the dentine pulp complex?
a dynamic tissue that responds mechanical, bacterial and chemical stimuli as a functional unit
Where is the dentine-pulp complex found?
in the dentine surrounding the pulp
What happens to the dentinal tubules in dentine closer to the pulp?
Number and size of dentinal tubules increases
Why do the number of dentinal tubules increase as it moves closer to the pulp?
To allow communication between the dentine and pulp via nerves and odontoblast extentions
How does tertiary dentine form?
Via communication through dentinal tubules by odontoblast processes, afferent nerve terminals and even processes of some immunocompetent cells
what is the function of dentinal fluid?
supply nutrients and structural materials to dentine via pulpal blood vessels
Which part of the tooth initiates an inflammatory response during dental disease?
dental pulp
what happens to the dental pulp if infection continues to progress?
death of dental pulp
What is the treatment following the death of dental pulp?
Endodontic treatment (pulp removal)
What happens to the dentine with pulp removal?
Dentine becomes an inert tissue incapable of any response or repair
Visually, what happens to the tooth when it becomes non vital?
discolouration
Mechanically, what happens to the tooth when it becomes non vital?
fracture
When is reactionary dentine formed?
During mild grades of injury, (shallow carious lesions/mild tooth wear related to erosion)
the odontoblasts and other pulpal cells underlying the lesion may well survive, and are stimulated or upregulated to secrete a reactionary type of tertiary dentine
What is reactionary dentine?
A wound-healing response to reconstruct circumpulpal dentine as a response to injury
What is required during reactionary dentine formation?
stimulation of existing odontoblast cells
What is reparative dentine?
The formation of dentine by a new generation of odontoblast-like cells which may consist of a “bridge” formation
When is reparative dentine formed?
When pulp is exposed, deepening of the carious lesion
What is required during reparative dentinogenesis?
Reparative dentinogenesis needs recruitment of progenitor cells from the pulpal tissue
What happens to the dentinal fluid when cutting burs produce vibrations during endodontic treatment?
Causes inward and outward fluid shifts
= A CRISIS for dentin-pulp complex
What happens following the fluid movement when cutting burs produce vibrations during endodontic treatment?
Barrage of hydrodynamic stimuli across the dentine into the dental pulp resulting in pain for the patient if not anaesthetised
What happens to the cells in dentine during endodontic treatment?
Displacement of odontoblasts= disruption of their internal cytoskeleton = cell death
What happens following cell death of odontoblasts?
cells are replaced by new odontoblasts over the next few days
- If the dentine is sterile and well-sealed, displacement of odontoblasts and their replacement with new cells would cause no pulpal inflammation.
list the stages of pulpal inflammation after a cavity prep
- dentine not sealed well following a cavity prep
- microleakage within the restoration
- acute pulpal reactions into chronic stage due to MICRO-ORGANISMS and thier products
