Midterm Questions Flashcards
The most important bond in PFM crown is?
Chemical
Metal alloys used for PFM restorations have this important characteristic
A fusion temperature higher than all of the porcelains that are fired onto the framework
What metal does not participate in the formation of the oxide layer of a PFM crown?
- Copper
Participate in the formation of the oxide layer of a PFM crown
- Tin
- Indium
- Iron
The glassy phase of porcelains is derived from?
Feldspar
When fabricating a custom tray how far would the borders be extended?
- 3-5mm cervical from the prepared margin
- Depth of the vestibule has nothing to do with it
When fabricating a custom tray, which of the following are correct with tissue stops?
- Should be preplaced on unprepared teeth
- Divergent locations to for a stable triad
- Cutting squares 4x4mm apart
Which is indicated for Treatment Planning a crown with subgingival margins?
Abutment has 0.5 ferrule effect (want to extend to make larger ferrule)
Which are characteristics of small chamfer margin preparation?
- Fairly conservatice
- Burnishable
- Detectable visually & tactile
Not a characteristic - Easy to Prepare
By increasing the connectors height from 2mm to 4mm the flexure of resistance will increase by how many times?
- Doubling the height of connector will not double the resistance but it does increase exponentially?
What kind of shape should a connector have when fabricating PFM fixed dental prosthesis from 12-14?
Triangular
When designing a FDP in anterior, where should the connector be placed?
Incisal 1/3rd
All ceramic FDP connectors should have an area of?
16sq mm
Which are examples of non-ridgid connectors?
- Mortise & Tennon
- Split Pontic
- Sub-occlusal
What type of prosthesis if the following?
Ancillary Prosthesis - made to do a function
- Made for pts that need radiation
- Alloy blocks and prevents rx
- Mouth is open
What are Fixed Prosthodontic’s main goals?
- Restore function and mastication
- Restore esthetics
- Retain helath & integrity of arches
- Sipport the tx of problems related to TMJ
When a full coverage Indirect Resotration becomes part of an FPD it changes name from corwn to?
Retainer
Proper proximal contact for a crown or FDP on a working cast is confirmed by?
Visual examination of proximal contact area is sufficient
All of the following statements are true concerning the intraoral evaluation of a crown except?
Flossing the proximal contact should fray
According to Dr. Sebert’s Ridge Classification, which type which is least prevalent in the general population?
Class II
Which pontic has no contact with the gingiva?
Hygiene Pontic
This tx is not extremely technique sensitive and should be considered a routine procedure by average general dentist?
Ridge Preservation
Which 2 Sebert Ridge Classifications share loss of ridge horizontal height (width)?
Class I and III
How much axial wall thickness is required, minimal for ferrule effect?
1mm
What are the Guidelines of the Post and COre?
- A post that is too short will increase the likelyhood of root fracture
- The post length should be 2/3 of the length of the root and have the length of the root in bone
- It should be 3-5mm from the apex, can not be less, to insure that we keep the canal sealed
- The purpose of the post is to retain the core
- THe purpose of the core is to provide retention & resistance of the crown
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