enamel

Question 1

state the physical properites of enamel

Answer 1

translucent
light yellow-gray white
2.5mm to feather edge
enamel thicker on the lingual surface of mandibular molars and buccal surface of maxillary molars due to functional demands
specific gravity of 2.8
permeability
abrasion resistance is high
young enamel is white, older enamel is yellow
refractive index of 1.62

Question 2

describe the structure of enamel

Answer 2

rods
composed of several million hydroxyapatite crystals.
each crystal is long, hexagonal in shape (40-60nm in width and 25-30nm in thickness)
packed in long thin rods 5-6 microns in diameter
rods run from DEJ to surface