L3: Dentine Caries

Question 1

what is the composition of dentine?

Answer 1

70% organic
20% inorganic
10% water

Question 2

what is the difference between tertiary and regular dentine?

Answer 2

tertiary is LESS mineralised

Question 3

what is the pulp-dentine complex?

Answer 3

a response between the dentine and pulp when there is injury

Question 4

what are the three components of a pulp-dentine complex?

Answer 4

1. Tubular sclerosis
2. Reactionary dentine
3. Inflammation of the pulp

Question 5

What is tubular sclerosis?

Answer 5

A component of the pulp-dentine complex leads to an increasing tubular obliteration = enormously reduces dentinal permeability

Question 6

what do odontoblasts do in tubular sclerosis?

Answer 6

1) Odontoblasts retract from the acid stimulus

2) Odontoblasts increase formation of peritubular dentine

Question 7

what is peritubular dentin?

Answer 7

a relatively dense mineralized tissue that surrounds the tubules of coronal tooth dentine

Question 8

During tubular sclerosis, what is the tracts distal (along) to the occlusion (blockage) called?

Answer 8

Dead Tracts

Question 9

Visually, how does tubular sclerosis differ from regular dentine?

Answer 9

More translucent on ground section due to higher mineralisation

Question 10

What is reactionary dentine?

Answer 10

Secondary dentine formed at pulp dentine interface; serves to increase distance between pulp and noxious stimulus

Question 11

For Low stimulus, describe the:

1) Rate of deposition of dentine
2) Tubules

Answer 11

1) Slow rate of deposition of dentine

2) Tubules regular

Question 12

For High stimulus, describe the:

1) Rate of deposition of dentine
2) Tubules

Answer 12

1) High rate of deposition of dentine

2) Tubules irregular

Question 13

What happens to dentine if odontoblasts die?

Answer 13

Atubular calcification may be formed by pulpal cells

Question 14

what is pulpitis?

Answer 14

inflammation of the pulp

Question 15

What is the three symptoms of pulpitis?

Answer 15

1) Increased blood flow-vascular dilation
2) Oedema

3 )Migration of neutrophils and macrophages (acute inflammation) plasma cells and lymphocytes (chronic inflammation)

Question 16

what is the shape of an enamel lesions?

Answer 16

1) Cone-shaped

2) Apex pointing to dentine

Question 17

at what part of the tooth does caries spread rapidly in a lateral direction?

Answer 17

EDJ

Question 18

Why do caries spread laterally rapidly at the EDJ?

Answer 18

Higher organic content and low fluoride of this region of enamel

Question 19

What is the visual representation of caries lesion in the enamel?

Answer 19

Tooth is bluish white

Question 20

Which surface of the tooth is more likely to have caries?

Answer 20

Fissure caries dentine surface areas involved greater than smooth surface caries

Question 21

During early caries lesion, describe:

1) Odontoblast response
2) Sterility of lesion and condition of enamel
3) Radiographic representation

Answer 21

1) - tubular sclerosis
- reactionary dentine.

2) Lesion is sterile, enamel intact no microorganisms

3) - Reduction in pulpal volume due to reactionary dentine formation
- Demineralisation of enamel (Darker marks on xray)

Question 22

What is early cavitation?

Answer 22

Following extensive subsurface demineralisation of enamel, surface may fracture and microorganisms penetrate occurs before or after caries has affected dentine

Question 23

What are the two main classes of microorganisms found in carious lesion?

Answer 23

1) Acidogenic (lactobacilli) bacteria

2) Proteolytic bacteria

Question 24

What is the movement of acidogenic bacteria in dentine tubules?

Answer 24

Acidogenic bacteria penetrate dentine tubules acid diffuses ahead

Question 25

What is the function of acidogenic bacteria in dentine tubules?

Answer 25

Causes demineralisation

Question 26

What is the movement of proteolytic bacteria in dentine tubules?

Answer 26

Remains in superficial region of dentine

Question 27

Where is multiplying bacteria found?

Answer 27

Multiplying bacteria lie parrallel to line of dentine tubules

Question 28

What is the function of proteolytic bacteria in dentine tubules?

Answer 28

Destroy organic matrix to form liquefaction foci

Question 29

What is liquefaction foci?

Answer 29

Liquified areas of dentine

Question 30

What are transverse clefts?

Answer 30

What is liquefaction foci?
Liquified areas of dentine
What are transverse clefts?
Liquefactive foci coalesce (gathering) form transverse clefts at right angles to dentine tubules

Question 31

During dental treatment, which dentine is removed in the early cavitation carious lesion?

Answer 31

Soft infected dentine

• keep the tubular sclerosis dentine as it is often intact

Question 32

What is advanced carious destruction?

Answer 32

Dentine destruction greater and tubular sclerosis destroyed, bacteria penetrate almost to pulp in advance zone of sterile demineralisation

Question 33

What happens to odontoblasts in advanced carious destruction?

Answer 33

Odontoblast may degenerate

Question 34

What happens to pulp in advanced carious destruction?

Answer 34

Marked pulpitis

Question 35

During dental treatment, what is removed in the advanced carious destruction lesion?

Answer 35

Remove soft dentine but beware exposure of pulp