Enamel Structure and Biomechanical Properties Flashcards Preview

BDS 2: Adult Restorative > Enamel Structure and Biomechanical Properties > Flashcards

Flashcards in Enamel Structure and Biomechanical Properties Deck (18)
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1

What is the enamel thickness of incisors?

0 to 2mm

2

What is the enamel thickness of molars?

0 to 2.6mm

3

What is the refractive index of enamel?

1.655

4

Comment on the solubility of enamel

Soluble in acids

5

What is Mucopolysaccharidosis?

- Genetic abnormality
- Doesn't allow enamel and dentine to bond at EDJ
- So could potentially cause cracks in enamel

6

Describe the crystallite orientation throughout the enamel

- All the crystals are in different directions
- Perpendicular from the EDJ

7

On the Moh scale what is the hardness of enamel?

5 to 8

8

What is the compressive strength of enamel?

350 MPa

9

What is the shear strength of enamel?

90 MPa

10

What is the tensile strength of enamel?

10 MPa

11

What is the maximum biting force administered to the teeth?

640 N

12

What is the maximum stress administered to the teeth?

20 MPa

13

What is the elastic modulus of enamel?

50GPa to 100GPa

14

Compare the elastic modulus of cross sectional enamel to surface enamel

Cross-sectional enamel has a lower elastic modulus than surface enamel

15

What does high fracture toughness show?

High fracture toughness shows improved clinical performance and reliability.

16

Comment on the structural integrity of enamel when there is crack propagation and subsequent fracture

Crack propagation and subsequent fracture leads to ultimate structural failure.

17

What is the enamel microstructure made of?

How does this help its function

Nano-scale HAP crystallites

High strength

18

Why is the thickness of crystallites 30nm?

This thickness is optimum for stress resistance