Term
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Definition
| Degreess of convergence of width |
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Term
|
Definition
1. Strong/Durable
2. Similar hardness to enamel
3. Inert/corrosion resistance
4. Accurate fitting
5. Minimal reduction needed
6. Simple manufacture process |
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Term
|
Definition
1. Aesthetics
2. Expensive
3. Inert (adhesion) |
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Term
|
Definition
1. Posterior teeth where aesthetcs not important
2. Teeth w/ limited starting height |
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Term
| What is marked on the impression of a crown prep for the lost wax technique |
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Definition
| The midpoint of the prepared and adjacent teeth |
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Term
| How is the model made for a crown |
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Definition
| The die stone is mixed under vacuum and vibrated into the impression |
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Term
| What is placed in the prepared and adjacent teeth of a crown prep model |
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Definition
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Term
| What happens next to a crown model with pins in it |
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Definition
| It is separated from the model with a thin saw blade |
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Term
| What is the the first layer applied to the model of a crown prep |
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Definition
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Term
| How is a thin layer of wax achieved on a crown prep model? |
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Definition
| It is dipped in molten wax |
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Term
| Why are porcelain jacket drowns rarely made? |
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Definition
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Term
| What does a dentine bonded crown require plenty of |
|
Definition
| Sound tooth tissue to bond to |
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Term
| What is the main use of dentine bonded crowns |
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Definition
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Term
| What are the features of a technical ceramic crown |
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Definition
| Porcelain crown with strong ceramic substructure |
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Term
| Disadvantages of tachnical ceramic crown |
|
Definition
Expensive due to need for technology
More destructive prep |
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Term
|
Definition
1. Aesthetic
2. Strong
3. Durable |
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Term
|
Definition
1. More tooth prep neeeded (porcelain needed to mask appearance of metal)
2. Patients with demanding aesthetic may reject the appearance of metal
3. Porcelain causing opposing tooth wear |
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Term
|
Definition
| Aesthetic considerations rule out appearance of gold |
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Term
| Porcelain build up of MCC |
|
Definition
1st Opaque
2nd Dentine
3rd Enamel |
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Term
| What does underpreparation of a crown prep casue |
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Definition
1. Weak sections of the crown
2. High points on the crown affecting occlusion |
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Term
| Properties of optimal taper |
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Definition
1. Preserve as much tooth tissue as possible
2. Provide good retention and resistance
3. Visible finishing line
4. Allow adequate seating of cast restoration |
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Term
|
Definition
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Term
| Factors affecting retention and resistance |
|
Definition
Taper
Surface Area
Length
Preparation design (aux. grooves/boxes)
Cement selection |
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Term
| Prevention of gingival damage |
|
Definition
1. Good OH
2. Supragingival margins where possible
3. Sufficient marginal reduction
4. Soft tissue management
Sufficient marginal reduction (bulbous margins = PRF) |
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Term
| What % of crowned teeth become non-vital |
|
Definition
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Term
| Material requirements of a crown/bridge |
|
Definition
1. Accuracy of fit
2. Strength to resist occlusal forces
3. Rigidity to avoid flexure and hence cement failure
4. Thermal expansion comparable to tooth
5. Biocompatible |
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Term
|
Definition
1. Adds colour
2. Tarnish/corrosion resistance
3. Adds density
4. Malleable |
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Term
|
Definition
1. Strengthens
2. Enhances colour (reddish) |
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Term
|
Definition
1. Whiten gold dramatically
2. Raises modulus
3. Improves strength/hardness |
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Term
|
Definition
1. Strengthens/hardens both gold/palladium
2. Raises thermal expansion
3. Lowers melting range of gold/palladium
4. Contributes to formation of bonding oxide |
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Term
| Effect of high levels of mercury |
|
Definition
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Term
|
Definition
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Term
|
Definition
1. Coping distrbutes stresses and provides rigid support
2. Coping inhibits cracks at ceramic/metal interface
3. Bond achieved by mechanical retention (roughness) and direct chemical bond (ion diffusion) |
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