Enamel Structure Flashcards
What are the 3 ways of bonding to teeth?
Bonding through micro-mechanical retention to enamel
Bonding to dentine
Direct adhesive materials through chemical bonds
What are the properties of ENAMEL?
(7)
Epithelial product
96% inorganic - hydroxyapatite
2mm thick max
Translucent
Non-vital
Hard (KHN 360-390)
Brittle
What is the chemical formula of Hydroxyapatite?
Ca10(PO4)6(OH)2
How do you examine a ground section of enamel?
Cut hard tissues
150μm thick section
Not stained
Light refracts
Light reflects internally
Hypomineralised areas appear dark
What is the basic unit of enamel and what are the 2 parts to it?
Enamel Prisim
- Prism core
- Prism Sheath
What type of course does enamel prisms take?
undulating course to give the enamel strength
What are the 2 regions of enamel prisms?
Both are Aprismatic:
– 1st formed (i.e. innermost) 5μm
– last formed (i.e. outmost) 30μm
What path do enamel prisms follow?
follow path of the ameloblasts ~ 90º to ADJ
What is labelled in the diagram of enamek?
represents a particular time of where the enamel WAS..
Any tooth that is forming at birth could produce what?
birth - “Neonatal Line
(it is an exagerated Striae of Retzius)
What is labelled in the diagram?
Perikymata
What is labelled?
What are enamel spindels?
Enamel Spindles –Dentinal tubules in enamel
What are the 4 lesion zones of caries?
Translucent zone
Dark Zone
Body of Lesion
Surface Zone
How can caries be arrested?
- Plaque control & Flouride
- altered diet
- can be brown
What happens in occlusal caries?
- 2 lesions
- Follow prisms
- Widening lesion
- Hard to detect
