Dentin Flashcards
What are 5 distinguishing properties of dentin?
- Dentin is sensitive
- Dentin is permeable
- Dentin is formed throughout life
- Dentin is softer than enamel
- Dentin has greater compressive and flexural strength than enamel
What colour is dentin?
Pale yellow
Rank in order of hardness:
Dentin, Cementum, Enamel
- Enamel
- Dentin
- Cementum
What forms dentin?
Odontoblasts
Where are the odontoblasts which form dentin found?
Outer border of the dental pulp
Describe the gross composition of dentin by volume
50% inorganic
30% organic
20% water
What is the main component of the organic component of dentin?
Collagen (principal fibril is Type I)
How do the collagen fibres run with respect to the pulp?
In parallel to the pulp surface
Name 2 other molecules which can be found in the organic component of dentin
- Dentine phosphoproteins
2. Proteoglycans
What 3 things can be found in dentinal tubules?
- Odontoblast processes
- Afferent nerve axons
- Dentinal fluid
What is a major feature, with regards to shape, of dentinal tubules
The have curvatures
What is a contour line of Owen?
Secondary curvatures which coincide in adjacent dentinal tubules
Where is a contour line of Owen usually found?
Junction of primary and secondary dentin
What is the function of dentinal tubules branching?
Allows intercellular communication
Where does the most profuse branching of dentinal tubules occur?
Dentinoenamel junction