L7: Principles Of Cavity Design: Modification Of Cavity For Different Restorative Materials

Question 1

What is vitality testing?

Answer 1

Assessing blood flow to tooth

Needs Doppler; ultrasound/laser

Question 2

What is Cavo-surface angle?

Answer 2

Angle of tooth on the inside of a cavity

Question 3

What are line angles?

Answer 3

All the different lines/angles within a cavity

Question 4

Sensibility testing is…

Answer 4

Assessing nerve supply

Question 5

What happens in caries INFECTED Dentine?

Answer 5

• Demineralization of Dentine
• Denaturing of collagen
• IRREVERSIBLE

Question 6

What happens in caries AFFECTED dentine

Answer 6

• Demineralization of Dentine
• No denaturing of collagen
• REVERSIBLE

Question 7

In what order to you remove enamel?

Answer 7

1. Gain/widen access to caries
2. Remove unsupported prisms
3. Remove demineralized margins

Question 8

In what order do you remove dentine?

Answer 8

1. Identify CID (Carie infected dentine)
2. Identify peripheral extent to EDJ
3. Excavate CID peripherally then towards the pulp
4. Excavate CID in depth

Question 9

In what case would you need to remove further carious dentine?`

Answer 9

Poor quality of peripheral enamel precluding seal
Inadequate moisture control at margin precluding seal
Symptoms of Pulpitis
High caries risk
Further structural support needed

Question 10

why would internal line angles be rounded?

Answer 10

to increase SA of enamel margins

Question 11

why restore teeth?

Answer 11

• To remove diseased tissue
• To restore integrity of tooth structure
• To restore function of tooth
• To restore appearance of tooth (aesthetics)
• To prevent recurrence of caries (microleakage)
• To provide durability and longevity

Question 12

What determines cavity design?

Answer 12

• Structure and properties of dental tissues
• Extent and nature of dental disease
• Properties of proposed Restorative Material

Question 13

How can you modify a cavity?

Answer 13

• Macroscopically (Large
scale)
– Created using a bur
• Microscopically (Small
scale)
– Created chemically

Question 14

what is retention (in terms of a restoration)?

Answer 14

– The property of a cavity/restoration that resists displacement of a restoration in the direction of
its insertion

Question 15

what is resistance (in terms of a restoration)?

Answer 15

– The property of a cavity/preparation that prevents displacement of a restoration in apical or oblique directions (other directions)

Question 16

Give examples of direct and indirect restorations

Answer 16

• Direct Restorations
– Plastic
– Mouldable
– Complex restorations
• Indirect Restorations
– Fabricated and finished in laboratory
– Luted into tooth chairside

Question 17

What are the properties of ana amalgam restoration?

Answer 17

– High strength (2mm+)
– Electrochemical corrosion
– High modulus of elasticity
– Dimensionally stable
– No inherent bonding to tooth substrate

Question 18

what are the macroscopic amalgam cavity modifications?

Answer 18

– Undercuts
– Slots and grooves
– Cavosurface angle
– Flat surface

Question 19

what are the microscopic amalgam cavity modifications?

Answer 19

– No inherent
– Bonded Amalgam
?????

Question 20

What is the cavosurface angle of amalgam cavity modifications?

Answer 20

90 degrees

Question 21

what are the properties of composite?

Answer 21

– Good aesthetics
– Bond to dental substrates
– More conservative tooth preparation
– No corrosion
– (Slightly) less durable (strong) than amalgam
– (Lower) modulus of elasticity
– Technique sensitive

Question 22

GIC properties

Answer 22

– Lower fracture strength (v composite & amalgam)
– Less tough (prone to wear)
– Poorer aesthetics
– Inherent (chemical) bond to dental substrates
– Fluoride release