ICP L9: Dentine-pulp complex Flashcards
Where do both the dentine and pulp originate from
Dental papilla
Describe the difference in composition between pulp and dentine
Dentine
- type I collagen
- no basement membrane so no type IV collagen
- no fibronectin
- has phosphoryn
Pulp
- type I III and V collagen
What is phosphophoryn
It is an abundant macromolecule in the extracellular matrix of mineralised dentine needed for remineralisation in the dental pulp
What is the role of odontoblasts
These are differentiated from the dental papilla
- lay down mantle dentine in the tooth germ
- forms primary dentine during tooth development
- deposit secondary dentine slowly throughout life
What is dentinal fluid
The fluid which is contained in dentinal tubules which is derived from the pulpal extracellular fluid
What is the role of pulpal blood vessels
Suppy nutrients and structural materials to dentine
What is the role of pulpal nerves
Mediate dentine sensitivity and play a role in regulating secondary and tertiary dentine deposition
What changes occur in the pulp in injury or dental caries
- starts an inflammatory response
- reversible can progress to irreversible pulpitis and death
What happens to the dentine when dental pulp dies or is removed
It becomes an inert tissue incapable of response to repair; this makes the tooth weaker and to appear discoloured
What is the aim of dentine-pulp complex reactions to stimuli
To reduce the permeability of dentine so that microorganism’s can’t reach the pulp and cause an infection
When is reactionary tertiary dentine produced
When the injury is mild meaning that odontoblasts and pulpal cells underlying the lesion survive and so these can be stimulated and unregulated to secrete reactionary dentine
When is reparative tertiary dentine produced
When the injury is extensive meaning that there is pulp exposure which leads to odontoblast death; progenitor cells will secrete the reparative dentine and this may lead to bridge formation contributing to the restoration of tooth integrity
What is the difference between reactionary and reparative dentinogenesis
Reactionary
= requires stimulation of existing odontoblast cells
Reparative
= recruitment of progenitor cells from the pulpal tissue
What happens when odontoblasts are displaced into dentinal tubules during cavity preparation
It disrupts their internal cytoskeleton and causes cell death and these will be replaced by new odontoblasts
Why is it important that the dentine is sterile and well sealed during cavity preparations
So that the displaced odontoblasts and newly formed odontoblasts will not cause pulpal inflammation
