Full removable dentures -Impressions and custom tray design Flashcards
1
Q
Workflow of impressions
A
1) Primary impression
2) Preliminary cast
3) Special tray
4) Final impression
2
Q
Materials for custom tray fabrication
A
- Polystyrene
- Shellac
- Cold cure resin
3
Q
Types of tray fits
A
Close fitting tray
Spaced tray
Windowed tray
4
Q
Close fitting tray use
A
When denture bearing area free from undercuts
5
Q
Spaced tray use
A
When undercuts present
6
Q
Windowed tray use
A
When fibrous ridges present
7
Q
Advantages of special trays
A
- Less material used than stock tray
- More accurate impression
- Even thickness of impression
- Less bulky and easier to work with
8
Q
Factors affecting use of stock tray
A
- Impression material type
- Size of arch
- Shape of arch
9
Q
Types of impressions
A
Diagnostic
Primary
Secondary
10
Q
Use of diagnostic impression
A
Used to make diagnostic casts for study purposes(Path of insertion, measuring undercuts)
11
Q
Use of primary impression
A
- For diagnosis or construction of a tray
- Alginate or impression plaster used
12
Q
Use of secondary impression
A
- Used to prepare master cast
- Makes use of custom tray made from primary cast
- ZnO euginol
