1. ENAMEL
1st
Year BDS
17-03-14

2. Slide Preparation Practical:
Roll # Group 1st Turn 2nd Turn 3rd Turn
1 - 10 A 3-Jan 4-Jan 3-Jun
11 - 20 B 1-Feb 2-Feb 4-Jun
21 - 30 C 3-Feb 4-Feb 5-Jun
31 - 40 D 1-Mar 2-Mar 1-Aug
41 - 50 E 3-Mar 4-Mar 2-Aug
51 - 60 F 5-Mar 2-Apr 3-Aug
61 - 70 G 3-Apr 4-Apr 4-Aug
71 - 80 H 1-May 2-May 1-Sep
81 - 90 I 3-May 4-May 2-Sep
91 - 100 J 1-Jun 2-Jun 3-Sep

3. Structure of Enamel

5. Introduction
Definition: The hardest mineralized tissue which
covers the dentin in the crown portion of the tooth
is called enamel.
Physical & Chemical Properties
 Living or non-living
 Thickness 2-2.5 mm
 Brittleness
 Permeability
 Color
 Translucency
 Radio-opaque

6. Composition
 Inorganic content: 96%
(Hydroxyappatite Crystal)
 Organic content: 4%
(Enamal proteins & Water)

7. Enamel Protein
 Amelogenins: 90%
 Non-amelogenins: 10%
Enamelin
Ameloblastin (Amelin/Sheathlin)
Tuftelin

8. Enamel Protein
 Non collagenous proteins
 Enzymes for degradation
(Enamelysin & Kallikrein4 (KLK4)
 Noval secretory proteins
(Amelotin & Apin)

9. Mano is my friend!!!!

10. Structure
Enamel rods
• Fish scale appearance
• Key hole appearance
Cross striations
Striae of retzius
Hunter-schreger bands
Gnarled enamel
DEJ
Surface enamel
•Perikymata
•Enamel cuticle
(Nasmyth’s membrane)

11. Age Changes
 Tooth wear (Attrition, Abbrition & Erosion)
 Occlusal facets
 Discoloration
 Color
 Reduced permeability
 Composition of surface layer

12. Defects of Enamel
1. Organic defects
2. Developmental defects

13. Organic Defects
Enamel spindles
Enamel tufts
Enamel lamellae

15. Developmental Defects
A. Hereditary Disturbances in the Structure of
Enamel
* Amelogenesis imperfecta
B. Acquired Disturbances in the Structure of
Enamel
* Focal enamel hypoplasia
* Generalized enamel hypoplasia

16. Amelogenesis Imperfecta
Stages of
Development of
Enamel
1. Enamel matrix formation
2. Calcification
3. Maturation
Types of
Amelogenesis
Imperfecta
1. Hypoplastic type
2. Hypocalcified type
3. Hypomaturation type

18. Focal enamel
hypoplasia
Generalized enamel
hypoplasia

19. Other developmental abnormalities
Fluorosis Tetracycline stains

20. Clinical Considerations
 Cavity prep.
 Deep fissures
 Lamellae
 Fluoridation
 Acid-etching

21. Ends

22. End