Final Review Flashcards
T/F Delayed cementation of fiber post resulted in higher retentive strengths in comparison to immediate cementation.
True
If a large gap exists what material should you use to cement the post?
-Core build up material
What are the most effective conditions for long term success of post endodontic restorations?
- Preservation of tooth tissue
- Ferrule
- Adhesion
- Good occlusion
What is a risk for fatigue fracture of teeth, cement, and restorative material?
-Nonaxial forces
What are the three conditions of tooth preparation?
- Mechanical
- Biological
- Esthetic
What are some of the limitations of alginate?
- Lacks fine detail
- Imbibition
How long is the recovery period for alginate?
10-15 minutes
What are the three resin cements?
- Adhesive
- Self adhesive
- Esthetic
What is the resin cement with the strongest bond?
-Adhesive
T/F Esthetic has to be used with a bonding agent
-True
What is an example of a self adhesive resin cement?
-Rely X unicem
What is Rely X luting plus?
-RMGI
When don’t you want to use Rely X luting plus?
- Posts
- Inlays
What are some of the properties of a Bis-GMA material?
- Tough
- Brittle (cautious for long span bridges)
- Contains an oxygen inhibited layer
What is a main temporary material we use today?
-Bis-Acryl
What is a temporary material that is a methyl-methacrylate that has to light cure?
-Unifast
What type of matrix do you use with unifast?
-Alginate (don’t use the putty matrix)
What is the most esthetic version of zirconia?
-High translucent
What does the high trans zirconia have in it?
-Cubic phase
What is the strongest phase of zirconia?
-Tetragonal
What stabilizes the tetragonal phase of zirconia?
- Yittria
- Ceria
- Alumina
What is the ideal length of the post?
2/3 to 3/4 of the root leaving 4-5 mm a gutta percha
If a tapered post where are the stresses transferred?
-Coronal
If a parallel post where are the stresses transferred?
-Apical
Does a longer or shorter post distribute the forces better?
-Longer
Is it ok to use a green stone to adjust zirconia?
-No because is causes a phase transformation
If a crack occurs in zirconia what is that known as?
-Transformation toughening
What are ways that zirconia can break down? (can cause tetragonal to monoclinic phase change)
- Fracture
- Increased abrasivity
- Low temperature aging degradation
- Increased hydrothermal solubility
Is it ok when preparing a build up to expose a pin?
-Yes
When is it unacceptable to expose a pin?
-When you almost cut the pin off
What is the first parameter you check when fitting a crown?
-Proximal contacts
When you are looking for value what vision are you relying on?
-Scotopic (rods)
If you error do you want to err on high or low value?
-High because its easier to darken it up
Where is the best place to get the dominant Hue?
-Cervical third of an unrestored upper canine
With a high speed hand piece what is important when cutting on teeth?
- Keep teeth wet
- Keep the waterports flowing (patent)
- Don’t cut on teeth if you can’t use copious amounts of water
Is it ok to cut dry on a tooth?
-Yes, on a non-vital tooth, or on a vital tooth if the rpms are very low and you keep the tooth moistened intermittently (little points of touch up)
What is the liquid component of IRM?
-Eugenol (oil of cloves)
Can you put Eugenol on a tooth with an exposure?
-Yes
What do you do if you have a pinpoint pulpal exposure?
- Keep the tooth moist
- Don’t let it get contaminated
- Do a direct pulp cap
Do you do direct pulp caps under indirect restorations?
-No
What is polyacrylic acid used in?
- The liquid component of zinc poly carboxylate (tyloc)
- Also used in a glass ionomer cement
- Used as a conditioner liquid for GI cements
What doesn’t polyacrylic acid cause post operative sensitivity?
-It is to large to get into the dentinal tubules
What is the difference between dimension accuracy and dimensional stability?
- (accuracy) material being accurate as it sets and during removal from the mouth
- (Stability) How long it stays that way and doesn’t distort
What is elastic recovery?
-Impression material ability to rebound to proper dimensions after being removed from the mouth
What are the properties of an addition silicone (PVS)?
-Gives have H2 gas scavaged by palladium
What is the by product of condensation silicones?
-Ethyl alcohol
What is the most hydrophillic of all elastomers?
-Polyether
What are the downsides of polyether?
- Terrible taste
- Stiffest of elastomers
Does a thin or thick biotype have more susceptibility to recession of the gingiva?
-Thin
Hydrocal is used to make what?
-Type III
-Densite is used to make what?
- Type IV
- Type V
How does glass ionomer adhere to tooth structure?
-Ionic bond between the calcium in the tooth and the carboxylate in the cement
How does zinc polycarboxylate adhere to tooth structure?
-Calcium chelation
What is the purpose of a base?
- Get back to ideal prepared tooth structure
- Serve as an insulator
Will a liner serve as an insulator?
-No but it does as a chemical carrier
What is the purpose of a build up?
-increase connection of the tooth to the restoration
What allows you not to use a post?
-Chamber retained build up
