Dental Anatomy 20 - [Enamel,dentin, pulp] Flashcards
Enamel develops from ____ which is derived from ____
Enamel organ
Ectoderm
Dentin and pulp develop from _____ which is derived from ____. It determines the shape of the
Dental papilla
Mesoderm
Developing crown
What happens in a later stage of the dental papilla
Condensation of cells
Permanent tooth bud developing lingual to the primary tooth dental papilla
What’s the hardest structure of the body
Enamel
What’s the enamel composition
96% inorganic
4% water + fibrous organic material
What’s the inorganic structure of the enamel composed of?
Crystals of hydroxyapatite
Parts of the enamel
Rod sheath - fibrous organic substance
Rod - primary unit of enamel’s structure
Etching of the dental enamel with acid removes the _____ and opens the enamel tubules
Smear layer
What’re the enamel rods
Column of enamel
From DEJ —> surface of tooth
Formed by 3-4 ameloblasts
What’s the asymmetric bulge of the ameloblast
Tomes process
What happens in the remineralization stage
Ameloblasts lay down a matrix
Deposit millions of HA crystals
What happens in the maturation stage
Crystals grown until tightly packed together
Brownish line in enamel marks, curved outwardly and occlusally from DEJ
Striae of Retzius
What’s the signal for the ameloblasts to cease formation of enamel
When ameloblasts contact the OEE
How do the cells of the IEE change to become preameloblasts
IEE become taller during the bell stage
Preparing to become secretory cells
