2. ENAMEL
INTRODUCTION
Enamel is a higly mineralised structure
covering the anatomic crown of tooth.
It is the only tissue that is totally acellular.
PHYSICAL PROPERTIES:
Colour:- appears bluish white or greyish at
the thick opaque areas & yellow-white at the
thin areas reflecting underlying dentin.
3. Hardness:-
hardest structure of the body i.e.5 to 8khn.
Permeability:-
selectively permeable.
Density:-
decreases from the surface of enamel to the
dentino-enamel junction.
Thickness:-
thickness over the cusps of the molars
where it measures 2.5 mm & incisal edges
of incisors where it is 2.0 mm.
4. CHEMICAL PROPERTIES
Enamel is composed of organic & inorganic substances
Organic --------> 4%
Inorganic--------> 96%
Water
STRUCTURE OF ENAMEL
1) Enamel rods(prisms)
2) Rod shealths
3) Cementing inter-rod substance.
6. Wavy course of enamel rod
• Enamel rods follows
a wavy course the
full thickness of
enamel
• A more spiral course
is noted at cusps &
incisal areas Gnarled enamel