Structural Components of Teeth Flashcards
What is enamel formed by?
a. What is this process called?
Ameloblast
a. Amelogenesis
What part of the tooth does enamel protect?
Anatomical crown
What part of the enamel is the hardest?
a. The density of enamel increases from?
b. What part of the occlusal surface is the enamel the thickest?
Peripheral
a. DEJ to surface
b. Cusp tips
What color is enamel?
a. What is enamel called when it can be different colors?
Semi-translucent
a. Polychromatic (thinner = yellowish white, thicker = blue-grayish white)
Does enamel have high compressibility?
a. Tensile strength?
b. Shear strength?
Yes
a. Low
b. Low
What is enamel supported by?
Underlying dentin
What dissolved enamel?
a. What reduces the solubility and increases the hardness?
Acid (demineralization)
a. Fluoride
Is surface or deep enamel more soluble?
Deep
Is enamel permeable? How does water and ions pass through enamel?
Yes (selective), Osmosis
What is the chemical composition of enamel?
a. What is the inorganic content of enamel?
b. What does fluoride do to the inorganic component and what does it do?
Inorganic = 96%, organic = 1%, Water 3-4%
a. Hydroxyapatite
b. Fluoride with calcium (replace –OH) → fluoroapatite (harder)
What does what do to the enamel?
Hydrated shell or covering around apatite crystal
What is the fundamental unit of enamel?
a. What are their shapes?
b. Permanent enamel rods radiate in a __________________ to _______________? Towards what surface?
c. Primary rods are ____________________ to __________________?
- Enamel prisms (rods)
a. Keyhole, interlocking
b. Perpendicular form surface, DEJ
c. Perpendicular, DEJ
What are Lines of Retzius?
a. Wave-like surface characterization called?
Incremental growth lines (Enamel), concentric series, brown lines, arc-like, wave-like
a. Perikymata
Alternating light and dark bands of enamel rods (artifact of specimen sectioning)?
a. Dark bands?
b. Light Bands?
Hunter-schreger bands
a. Diazones
b. Parazones
What is the main component of teeth?
a. What is this formed by?
b. What is this process called?
Dentin
a. Odontoblast
b. Dentinogenesis