management of caries

Question 1

What is dental caries?

Answer 1

Reversible but progressive
Bacteria upon fermentable carbs in the plaque biofilm on tooth surfaces
Leads to acid demineralisation and proteolytic destruction of dental tissues

Question 2

What is Keyes’ triad?

Answer 2

Tooth, micro flora, diet and time=tooth decay

Question 3

What are the three most common susceptible tooth sites?

Answer 3

Pits and fissures of occlusal surfaces of posterior teeth
Area below contact point
Surface adjacent to gingival margin

Question 4

How do carious lesions develop?

Answer 4

An imbalance in favour of pathologic factors over a sustained period of time
Protective vs pathological

Question 5

What is an early carious lesion?

Answer 5

Non-cavitated and limited to enamel- white spot lesion

Don’t need operative intervention but need preventative

Question 6

What is the Stephan Curve?

Answer 6

The intra oral pH which is typically 7-6.5 will drop below the critical pH 5.5 for about 8 mins or so
There’s a net loss of minerals
If this continues over time- caries
Saliva remineralises

Question 7

How might a white spot lesion progress?

Answer 7

No change in oral environment
Demineralisation progresses, weakens enamel, reaches ADJ
Reaches dentine and spreads along ADJ
Enamel breaks under occlusal forces=cavity

Question 8

Why does a cavity require operative intervention?

Answer 8

Can’t feasibly remove plaque
Bacteria remains, food gets stuck
Progression much quicker in dentine

Question 9

What is infected dentine?

Answer 9

Outermost, irreparable, necrotic zone
Dark, mushy, wet, soft
Denatured collagen matrix 
High bacterial load
Tubular structure destroyed

Question 10

What is affected dentine?

Answer 10

Inner layer, reparable
Paler brown, harder, leathery
Collagen damaged to lesser extent 
Less bacterial load
Tubular structure foundations remain
Unnecessary to remove

Question 11

How do you detect caries?

Answer 11

Magnify
Illuminate
Clean
Blunt ended probe- round/ball
3-in-1 air/water syringe

Question 12

What special tests may be used to identify caries?

Answer 12

Radiographs
Transillumination
Quantitative Laser Fluorescence
Electrical Impedance devices
Tooth separation w ortho devices

Question 13

How can caries be controlled non-operatively?

Answer 13

Oral hygiene instructions 
Plaque control
Diet advice
Fluoride
CPP-ACP
Antimicrobial agents (chlorhexidine, xylitol)

Question 14

What is CPP-ACP?

Answer 14

Casein phosphopeptide-Amorphous Calcium Phosphate
Tooth mousse
Provides calcium and phosphates
Eg. Every couple of hours

Question 15

What are the three aims of operative management?

Answer 15

1. Aid plaque control to manage caries
2. Protect pulp-dentine complex and arrest lesion by sealing
3. Restore function, form and aesthetics

Question 16

What are three caries removal techniques?

Answer 16

Complete caries removal
Stepwise caries removal
Partial caries removal

Question 17

What is complete caries removal?

Answer 17

Removal of ALL carious tissue
Leaves sound enamel and dentine
Completely clean
~ outdated, removes healthy and increases pulpal complications

Question 18

What is Stepwise caries removal?

Answer 18

Appt 1- open cavity, remove infected dentine and place temp restoration for 2-6 months
Appt 2- remove restoration, remaining caries at base and place definitive restoration
~ lower pulp exposure chance due to tertiary dentine being placed

Question 19

What is partial caries removal?

Answer 19

Selective removal of all carious enamel and infected dentine
Leave affected dentine at base
Leave sound enamel, sound dentine at ADJ
~ removes less tooth and preserves pulp vitality

Question 20

What are the steps of caries removal?

Answer 20

1. Enamel access
2. Clear ADJ, sound margins
3. Management of unsupported enamel
4. Management of body of carious lesion

Question 21

What hand instruments are used to remove caries?

Answer 21

Chisels- gingival margin trimmers, hatchets and straight chisels
~manage carious and unsupported enamel
Excavators- spoon exc.
~remove carious dentine and clear ADJ

Question 22

What are the advantages of hand instruments?

Answer 22

Controlled removal
Tactile feedback
Simple and cheap
No noise or vibration

Question 23

What are the disadvantages of hand instruments?

Answer 23

Time consuming
Exclusive use limited to open cavities
Operator fatigue

Question 24

What rotary instruments are used to remove caries?

Answer 24

High speed handpiece/air rotor-
~air powered (pneumatic)
~up to 450000rpm
~internal water cooling system
~friction grip burs (pear and round diamond)
Slow handpiece/contra-angle-
~powered by motor
~modifiable speed, 40000rpm
~may not have internal water cooling
~latch grip burs (rose-head)

Question 25

What are the advantages of rotary instruments?

Answer 25

More efficient
Used for any type of lesion
Tactile feedback
Versatile- diff speeds, burs, angulations

Question 26

What are the disadvantages of rotary instruments?

Answer 26

Noise/vibrations
Significant heat- cooling required
Less control
Produce aerosol

Question 27

What is chemo-mechanical caries removal?

Answer 27

Proteolytic chemical breaks down organic tissue in caries
Removed w excavators
Eg. Carisolv, Papacarie

Question 28

What are the advantages of chemo-mechanical?

Answer 28

Controlled removal
Tactile feedback
Reduce need for local anaesthetic
No noise/vibration

Question 29

What are the disadvantages of chemo-mechanical?

Answer 29

Time consuming
Limited to open cavities
Selective removal claims not proven
More fatiguing

Question 30

What about other techniques eg. Air abrasion, lasers, ultrasonic?

Answer 30

Reduce need for anaesthetic
Improve patient comfort
Air abrasion- improve bonding for composite
But
Time consuming
Expensive
Lack of tactile feedback
Can’t remove soft caries