Operative Flashcards
How deep should ditching be to consider replacing a restoration?
0.5 mm
What do the four numbers on hand instruments represent?
- Width of the blade in tenths of mm, 2. Primary cutting angle, 3. Blade length in mm, 4. Blade angle
What is the rpm range for slow speeds, intermediate speeds, and high speeds?
- <12,000, 2. 12,000 - 200,000 and 3. >200,000
Define Outline form:
Knowing the shape of the restoration and the depth that it should be at
Define Primary Resistance form:
Having flat box floors, pulpal floors, etc. The main goal is to avoid any sort of fracture from occlusal forces
Define Primary Retention Form:
Shape, height, and form of preparation walls to prevent dislodgement of restoration.
Define Convenience Form:
Any alterations that improve access and visibility in restoration
Define Secondary Resistance/Retention Forms:
Locks, grooves, coves, etc. - note that they should be placed after the liner
What depth should be used for amalgams occlusally?
1.5 mm or 0.2 mm beyond DEJ - whichever is deeper
What axial depths should be used for amalgams?
0.2 mm w/o retention locks and 0.5 w/ retention locks
What are the two major downsides to using spherical amalgam?
- Greater leakage and 2. Greater postoperative sensitivity
How much percentage of dentin permeability is lost when the smear layer is present?
86%
What percentage is the coefficient of thermal expansion for dentin when compared with resin?
1/4
How much stress is created by polymerization shrinkage in composites in megapascals?
7
What terminology describes the difficulty resin has with polymerization shrinkage when the restoration is large and complex?
C Factor
What size are the particles in macrofilled composites?
10 Microns
What size are the particles in microfilled composites?
0.04 microns
What size are the particles in hybrid composites?
1 micron
What size are the particles in microhybrid composites?
0.4 to 0.8 microns
What margin (in degrees) is best for gold inlays/onlays?
30-50 degrees (30-40 ideal)
Which bur is recommended for gold inlays/onlays?
271
What degree of taper should each exit angle have for gold inlays/onlays?
2-5 degrees
What bevel width is best for a gold inlay/onlay?
0.5 mm
What areas do best with a 40 degree angle in gold inlays/onlays? (4)
- Occlusal bevel, 2. Groove extension bevel, 3. Secondary flare, and 4. Skirt
