5. Indirect Restorations

Question 1

What are the 7 indications for indirect restorations?

Answer 1

1. Repeated failure of direct restorations
2. Difficulty achieving adequate tooth morphology via direct techniques
3. To minimise risk of tooth fracture
4. Aesthetics
5. To combine with a removable prosthesis
6. For bridge abutment
7. To replace an existing crown

Question 2

What are the 5 contraindications for indirect restorations?

Answer 2

1. Poor oral health
2. Active disease
3. Inadequate crown height
4. Inadequate access
5. If there is a more minimally invasive option available

Question 3

What are the 5 steps of a crown preparation?

Answer 3

1. Occlusal red auction
2. Buccal reduction in 2 planes
3. Palatal/ lingual reduction
4. Interproximal reduction
5. Define margins

Question 4

What is a shoulder margin cut with?

Answer 4

Square, flat bur end

Question 5

What is a chamfer margin cut with?

Answer 5

Round bur

Question 6

How is GP removed for a post crown?

Answer 6

GP is softened with heat/chemicals then removed with a series of gates gladdens burs

Question 7

How is a post space prepared?

Answer 7

By drilling vertically up and down within the root canal system with a series of burs

Question 8

How is a resin retained bridge prepared?

Answer 8

1. Intra-enamel cingulum rest cut

Question 9

What are the 4 types of conventional bridge?

Answer 9

Fixed - fixed = abutment teeth at either side of pontic
Cantilever = abutment at one side of the pontic only
Fixed Movebale = ?
Complex = any other?

Question 10

How is a conventional bridge prepared?

Answer 10

Same way as a crown

Question 11

What is the 4 step process of preparing a tooth for a crown?

Answer 11

1. Take pre-op putty impression and take a shade
2. Cut tooth preparation
3. Take impressions of preparation using light and heavy body material
4. Make temporary restoration using pre op putty and pro temp

Question 12

List 5 ways to make a temporary restoration:

Answer 12

Putty index + pro temp
Preformed crowns
Pre-op wax up and vacuum formed stent
Free hand
Previous crown

Question 13

List the 5 materials used for crowns, bridges and veneers

Answer 13

Metal
Metal ceramic
Ceramic
Composite
Acrylic

Question 14

What margin is required for a metal crown?

Answer 14

Any

Question 15

What margins are required for a metal ceramic crown?

Answer 15

Shoulder for ceramic portion
Chamfer for metal portion

Question 16

What margin is required for a ceramic crown?

Answer 16

Chamfer

Question 17

What margin is required for a composite crown?

Answer 17

Chamfer

Question 18

What are the 6 principles of tooth preparation?

Answer 18

Conserve tooth tissue
Resistance form
Retention form
Structural durability
Marginal integrity
Preserve the periodntium

Question 19

What is an inlay?

Answer 19

An indirect restoration that sits on/in the occlusal surface only

Question 20

What is an onlay?

Answer 20

An indirect restoration that covers the cusps

Question 21

What are the indications for inlays/onlays?

Answer 21

Weakened teeth
To correct occlusion
To reorganise occlusion

Question 22

What are the advantages of inlays/onlays?

Answer 22

Protects the cusps
Reduces amount of tooth removal required

Question 23

What are the disadvantages of inlays/onlays?

Answer 23

Complex to prepare
Complex to fabricate
Expensive

Question 24

What materials can be used for inlays/onlays?

Answer 24

Good
Ceramic
Composite

Question 25

What is a core?

Answer 25

A restoration placed in teeth prior to preparation for an indirect restoration.

Question 26

What are the indications for cores?

Answer 26

Heavily restored teeth Heavily broken down teeth

Question 27

What materials can be used for cores?

Answer 27

Amalgam Composite GI GMGI Compomers Metal alloys

Question 28

What is a post?

Answer 28

A post restoration placed within the root canal system to facilitate a core build up if there is insufficient tooth structure to hold a crown.

Question 29

Where would you place a post crown?

Answer 29

Anterior teeth only

Question 30

What type of posts are there?

Answer 30

Direct - prefabricated and placed chair side Indirect - made in lab

Question 31

What is an articulator used for?

Answer 31

Aims to reproduce the relationship of the jaws in RCP or ICP.

Question 32

What are the 4 types of articulators?

Answer 32

Simple hinge Average value Semi adjustable Fully adjustable

Question 33

When would a face bow be used?

Answer 33

When more than one unit is being replaced

Question 34

Why would a face bow be used?

Answer 34

To allow casts to be mounted on a semi or fully adjustable articulator

Question 35

What is the purpose of a face bow recording?

Answer 35

To record the relationship of the maxillary teeth to the condylar head in RCP.