Dentine Caries Flashcards
What is the structural composition of dentine?
- 70% inorganic
- 20% organic
- 10% water
What do odontoblasts differentiate from?
Differentiate from cells of dental papilla
What do odontoblasts secrete? How do these help in the formation of mantle dentine?
Odontoblast process secretes HAP crystals that mineralize collagen matrix
How are dentine tubules linked to odontoblasts?
Dentine tubules contain cytoplasmic processes of odontoblasts
What is the width of the dentine tubules at
Pulp?
EDJ?
- Widest near pulp 2.5µm
- Narrowest at EDJ 0.9µm
Describe the location of the dentine tubules
Extend from odontoblast layer at pulp to enamel-dentine junction
Primary dentine;
When is it laid down?
Dentine-pulp complex response?
- Laid down in dentinogenesis
- Normal dentine-pulp complex response
Secondary dentine;
When is it laid down?
Dentine-pulp complex response?
- Laid down throughout life
- Normal dentine-pulp complex response
Tertiary dentine;
When is it laid down?
Dentine-pulp complex response?
- Laid down in response to noxious stimuli
- ‘Altered’ dentine-pulp complex response
What occurs to lesions during late enamel caries?
What response is initiated?
Progressing legions approach EDJ, which initiates defensive dentine pulp reactions
What occurs to lesions during dentine caries?
Lesions crosses EDJ and spreads into dentine
Why is there lateral spread at the EDJ for dentine caries? (3)
- Dentine mantle is hypo mineralised
- Increased side branching of tubules
- Defects within tissues of EDJ
When can you no longer reverse dentine caries?
Infected dentine tubules cause proteolytic dissolution
Explain clinically what a caries infected zone is
Appearance? Mineral components? Collagen? Bacterial load? Dentine tubules?
- Dark brown, soft, wet, ‘mushy’
- Mineral component dissolution
- Collagen matrix denatured
- High bacterial load
- Dentine tubules destroyed
Explain clinically what a caries affected zone is
Appearance? Mineral components? Collagen? Bacterial load? Dentine tubules?
- Sticky, scratchy, leathery
- Mineral component dissolution (lesser degree)
- Collagen matrix damaged by proteolysis but not denatured
- Lower bacterial load
- Dentine tubules remnants intact