MCQ Questions Flashcards
At what temp does feldspathic ceramic form leucite?
- 1150-1500degrees C
What is Leucite?
- Potassium aluminium silicate
What is PROCERA?
- > 99% alumina core- Produced at about 1700 celcius
What temp is Zirconia sintered at?
- 1600C
What is the max amount of strain porcelain will undergo before fracture?
- 0.5%
What is the expansion of gold ?
- 1.4%
What is the expansion of Ni/Cr?
2.0%
What is the expansion of Co/Cr?
2.3%
What is the longevity of GIC, SSC and Amalgam?
SSC = 92%Amalgam = 80%GIC = 66%
What are the reasons and % for post core failures?
- 60% due to restorative- 32% due to perio- 8% due to endo
What are some temp materials used?
PMMA:JetPEMA: Snap / TRIMBis-acrylate composite : ProtempUDMA : Provipont
What material has best mechanical properties for restoration of occlusal surfaces?
- Gold
What is the best method for retaining a core ?
- Use of adhesive only
When preparing upper first permanent molar for metal-ceramic crown, a functional bevel is placed on which cusp?
- Mesio-palatal
What is the correct degree of axial-taper in ideal crown prep?
- 7degrees