Advanced Restorations

Question 1

Define extra-coronal restorations

Answer 1

Restorations not limited to crown of tooth

Question 2

Define intra-coronal restorations

Answer 2

Restoration contained within crown of tooth, rest of the tooth in tact

Question 3

Define indirect restoration

Answer 3

Impression taken, restoration made outside of the mouth in the lab

Question 4

Define direct restoration

Answer 4

Made directly into the mouth

Question 5

List 4 uses of indirect restorations

Answer 5

Structural integrity
Restore form and function
Aesthetics
Replacing missing teeth

Question 6

List 2 advantages of direct extra-coronal restorations

Answer 6

One visit
No pre-visualisation required
Cheaper

Question 7

List 3 disadvantages of direct extra-coronal restorations

Answer 7

Difficult to re-create contact points
Occlusal control difficult
Materials not as strong and rigid as indirect

Question 8

How are indirect restorations classified?

Answer 8

By coverage - full coverage, partial coverage, intra-coronal (no cusp coverage)
By material - all metal, all ceramic, PFM, composite
By cementation method - mechanical e.g. conventional cement, adhesive e.g. resin cement

Question 9

What are the 2 types of ceramic that can be used for indirect restorations?

Answer 9

Emax (etchable)

Zirconia (not etchable)

Question 10

Describe the types of stress on anterior restorations?

Answer 10

Palatal surface under tension, buccal surface under compression

Question 11

In anterior restorations the palatal surface is under tension and the buccal surface is under compression, why is this important?

Answer 11

Tooth replacement materials do not behave well under tension but do behave well under compression

Question 12

Why are endodontically treated teeth lost?

Answer 12

Re-infection
Periodontal disease
Fracture/caries (lack of tooth structure)

Question 13

What traffic light system is used to determine whether a tooth can be restored predictably?

Answer 13

Perio
Restorations (caries, can it be isolated)
Endo
Other e.g. money, risks, how important is tooth, what does patient want

Question 14

What needs to be discussed with patient before prepping crown?

Answer 14

The tooth we want to restored is very compromised and weak, it is at risk of fracturing and loosing more tooth. We want to stop this to keep it in your mouth as long as possible.
However, I can not guarantee how long this will last as the tooth is already compromised.
To do this we will take some impressions and give you a temporary restoration so you are never without a tooth. You will then come back a week later and we will fit a crown made by the lab. There is a risk this tooth could lose vitality and die - this would cause pain and may mean the tooth has to be extracted (15% chance). Crowns tend to also around 5 years, this depends on individuals, how much tooth tissue remains, OH motivation

Question 15

What is the ferrule effect?

Answer 15

Minimal height 1.5mm, minimal taper

Question 16

Cuspal coverage indications for compromised posterior teeth?

Answer 16

All non-vital (root filled teeth)
In vital teeth:
Marginal ridges lost and connected, thin cusps, cracked tooth syndrome

Question 17

Why are posts less commonly used in posterior teeth?

Answer 17

Multiple canals that can be used for retention

Question 18

What 6 things must you do before you start treatment for crown?

Answer 18

Stabilise oral environment - per, restorations, endo
Holistic treatment planning - think about tooth and patient
Ensure healthy pulp or satisfactory RCT - PA required, vitality test non-RCT teeth
Ensure sound core
Realistic discussion with patient
Plan final restoration - how will it be retained? how will it be prepped?