Histology of Enamel

presented by Dr.N.ROBINSON SINGH

1. HISTOLOGY OF ENAMEL
Presented by: N. Robinson(CRRI)

2. 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.
ENAMEL

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
1) Enamel rods(prisms)
2)Rod shealths
3)Cementing inter-rod substance.
STRUCTURE OF ENAMEL

5. Enamel Rod
• Longitudinal section

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

7. • Enamel Rod: Basic
Structural Unit

8. Cross section of enamel

9. Microscopic picture of Enamel
Brown striae ofRetzius

10. DEJ, E tufts, E spindles

11. Enamel lamellae & Cracks

12. Perikymata (imbrication lines)
Are external manifestations
of Retzius striae

13. Development of Tooth
•Tooth and Associated Structures

51. THANK YOU