Histology of the Carious Lesion

Question 1

Dentin is comprise of ____ by weight of mineral and ____ by weight by organic matrix.

Answer 1

70%

20%

Question 2

Is the % of foreign ions in dentin or enamel greater?

Answer 2

Dentin

Question 3

What is the organic matrix made of?

Answer 3

Collagen

Question 4

What is the mineral in dentin made of?

Answer 4

Hydroxyapatite

Question 5

Which is a slower process demineralization or remineralization?

Answer 5

Remineralization

Question 6

Are the majority of early child carious lesions sterile and should they be restored?

Answer 6

60% of them are sterile (still have surface layer in tact) and should not be restored.

Question 7

What are the 4 zones of caries development in enamel and which zone is closest to enamel?

Answer 7

1. Translucent zone.
2. Dark zone.
3. Body of lesion. (largest)
4. Surface zone.

Zone 4 is closest to enamel.

Question 8

What is a first degree reaction to caries?

Answer 8

Fatty degradation undergoes calcification and plugs dentinal tubule.

Question 9

What is a 2nd degree reaction to caries?

Answer 9

Injury causes degeneration of entire odontoblastic process.
Calcified barrier at the pulp.
= dead tract.

Question 10

What is a third degree reaction?

Answer 10

Entire odontoblast dies.

Question 11

What are the 4 zones of caries development in dentin?

Answer 11

1. Normal
2. Transparent
3. Turbid layer (demineralized dentin)
4. Infected layer