OB- enamel Flashcards
Describe the pattern of mineralisation in enamel?
The surface enamel is harder and more mineralised than deeper enamel.
Compare Enamel Rods to Interrods?
Enamel rods make up enamel and run perpendicular
whereas
The Interrod regions between the rods run more parallel.
Why do we have head and tail regions in the structure of an enamel rod?
Due to a variation in the hydroxyapatite crystal orientation
How does the enamel composition change after treatment?
You can lose water and the organic matrix.
Losing the organic matrix reduces the flexibility of the material. This reduces the ability of enamel to withstand force.
What histological characteristic is shown in this image?
The black lines are Hunter Schreger bands.
These are absent in outer enamel.
What histological characteristic of enamel is shown in this image?
This is gnarled enamel and shows a greater concentration of enamel rods.
What histological characteristic of enamel is shown in this image?
This is Perikymata which is only present on newly exposed enamel and this wears away.
What histological characteristic of enamel is shown in this image?
This is the neonatal line that is a consequence of birth.
Found in newborn’s teeth
Compare enamel rods and dentinal tubules at the ADJ
We look at the line size.
The wider lines are the dentinal tubules
The thinner lines are enamel rods.
Compare the lines of enamel marked A and B in this histological image
A- These are Enamel tufts which are hypomineralised regions at the prism boundaries that penetrate the rods
B- these are Enamel Lamella which is the incomplete maturation of groups of prisms. These penetrate all the way through enamel.
What are enamel spindles/
Odontoblast processes that extend into the enamel.
What is the advantage of gnarled enamel?
The higher concentration of enamel rods means that the enamel at this area can withstand more forces.
Why are hunter schreger bands formed?
Due to the regular change of enamel rod direction.
What histological characteristic of enamel is shown in this image?
Brown striae of Rhetzius.
These are bands that show the weekly formation of enamel which is formed at intervals.
Why is the ADJ scalloped?
To give more mechanical retention between enamel and dentine
