W4. Cavity preparation designs for direct restorations

Question 1

I. Preparation types
1. What are the 3 preparation types?

Answer 1

1. MACRO retention
2. MACRO + MICRO retention
3. MICRO retention

Question 2

I. Preparation types
2. Describe MACRO retention

Answer 2

Question 3

I. Preparation types
3. Describe MACRO + MICRO retention

Answer 3

Question 4

I. Preparation types
4. Describe MICRO retention

Answer 4

Question 5

II. Conventional preparation
1. Which principle is conventional preparation based on?

Answer 5

Based on Black’s principles

Question 6

II. Conventional preparation
2. What are Black’s principles?

Answer 6

1. Extension for prevention
2. Preparation is always extended into dentin
3. BOX shape
4. CONVERGENT/ parallel walls, Isthmus, Dovetail
   (retention form)
5. Flat pulpal and gingival walls (resistance form)
6. MARGINS- on sound structure
7. SECONDARY retention form

Question 7

II. Conventional preparation
3. What does extension for prevention mean by Black’s principles?

Answer 7

1. Preparation is extended into the not decayed surface
2. Extension to self-cleaning surfaces (ducally orally)
3. Unsupported enamel is always removed

Question 8

II. Conventional preparation
4. What does Preparation always extended into dentin for prevention mean by Black’s principles?

Answer 8

Amalgam-minimalthickness1,5

Question 9

II. Conventional preparation
5. What does MARGINS mean by Black’s principles?

Answer 9

ARGINS- on sound structure
-> Amalgam- 90 degrees

Question 10

II. Conventional preparation
6. What does SECONDARY retention form mean by Black’s principles?

Answer 10

Retention lock, grooves, coves, skirts, pins, slots

Question 11

II. Conventional preparation
7. Identify

Answer 11

1. Dovetail
2. Isthmus

Question 12

II. Conventional preparation
8. Identify

Answer 12

1. Amalgam
2. Inlay (metal)

Question 13

II. Conventional preparation
9A. Describe outline form?

Answer 13

Question 14

II. Conventional preparation
9B. Describe retention form?

Answer 14

Question 15

II. Conventional preparation
9B. Describe resistance form?

Answer 15

Question 16

II. Conventional preparation
9B. Describe convenience form?

Answer 16

Question 17

II. Conventional preparation
10. What is the indication for conventional preparation?

Answer 17

The restorative material adheres to the tooth macromechanically.
1. Occlusally convergent walls (amalgam)
2. Almost parallel (1-2° divergent) walls (metal inlay)
3. NO enamel- NO micromechanical retention (adhesive technique)

Question 18

III. Beveled conventional preparation
1. Describe Beveled conventional preparation

Answer 18

1. Conventional preparation + beveling of enamel margins + optionally secondary retention elements
2. MACRO + MICROretention

Question 19

III. Beveled conventional preparation
2. What is the indication for Beveled conventional preparation?

Answer 19

1. Changing old amalgam filling to composite
   (the shape and size of the cavity is defined by the existing restoration)
2. Not enough enamel surface
   - Caries extends onto root surface

Question 20

IV. Beveling of enamel margins
1. Describe Beveling of enamel margins

Answer 20

1. Only in enamel
2. SURFACE ENLARGEMENT
3. Width of bevel: 0,5-1mm, 45°

Question 21

IV. Beveling of enamel margins
2. When should we have NO Beveling of enamel margins?

Answer 21

1. Occlusally- The thin edge breaks on occlusal forces
2. In case of narrow vestibulo-oral aproximal box

Question 22

IV. Beveling of enamel margins
3. When should we have Beveling of enamel margins?

Answer 22

1. In case of wide vestibulo-oral approximal box
2. Enamel margins where there is no contact with the antagonist

Question 23

V. Minimal invasive preparation
1. Describe Minimal invasive preparation

Answer 23

1. Composite fillings (use adhesive technique)
2. Defect-oriented
3. NO preventive extension
4. NO special cavity design

Question 24

V. Minimal invasive preparation
2. When should we have no beveling during Minimal invasive preparation?

Answer 24

1. Occlusally (masticatory forces)
2. Enamel margins where there is contact with the antagonist
3. Approximally-in case of narrow vestibulo-oral approxima lbox

Question 25

V. Minimal invasive preparation 3. When should we have beveling during Minimal invasive preparation?

Answer 25

1. Enamel margins if there is no contact with the antagonist (not in occlusal) 2. Approximal - in case of wide vestibulo-oral approximal box

Question 26

VI. Extra 1. Which material is used for the filling of class I caries?

Answer 26

Question 27

VI. Extra 2. What type of preparation should we use for class II caries?

Answer 27

1. Conventional 2. Beveled conventional 3. Minimal invasive

Question 28

VI. Extra 3. What type of preparation should we use for class III caries (Root surface caries)?

Answer 28

1. Conventional 2. Beveled conventional 3. Minimal invasive 4. Beveled conventional+ Conventional

Question 29

VI. Extra 4. What type of preparation should we use for class IV caries?

Answer 29

1. Conventional 2. Beveled conventional 3. Minimal invasive

Question 30

VI. Extra 5. What type of preparation should we use for class V caries?

Answer 30

1. Conventional 2. Beveled conventional 3. Minimal invasive 4. Modified conventional

Question 31

VI. Extra 6. What type of preparation should we use for class VI caries?

Answer 31

Minimal invasive preparation

Question 32

VI. Extra 7. What type of preparation should we use forRoot surface caries?

Answer 32

Conventional preparation