CVC Prep (22) Flashcards
For a prep on #30, what teeth should the putty impression cover?
28-#31
What bur should be used for occlusal guide grooves?
L-242.6M on high speed
What should be the depth difference between orientation grooves and final prep?
0.2mm shallower
Where should occlusal depth orientation grooves be placed?
Triangular cusp ridges
Grooves
What bur should be used for occlusal reduction?
L-242.6M on high speed
What should the planes of occlusal reduction correspond to?
Anatomical features of the unprepared tooth
What should the functional cusp bevel angulation be?
45 degrees to the long axis of the tooth
What bur should be used for the axial guide grooves?
L-242.6M on high speed
What do axial guide grooves determine?
The eventual POW
How far should the chamfer be from the gingiva?
0.5mm or 1.0mm coronal to CEJ (whichever is more coronal)
This gives enough space to ensure periodontal health while providing sufficient length for resistance and retention
How much clearance should there be from the prep to the adjacent tooth?
0.5mm
What will happen if there is excessive taper?
Dramatically reduce the retention and resistance of the prep
Functional cusp reduction measurements
- 5mm
1. 3-1.7mm
Central groove reduction measurement
- 0mm
0. 8-1.2mm
Non-functional cusp reduction
- 0mm
0. 8-1.2mm
POW measurement
+/- 5 degrees
Convergence angle measurement
6 degrees
2-10 degrees
Chamfer width measurement
- 5mm
0. 4-0.7mm
Interproximal chamfer width measurement
- 5mm
0. 3-0.7mm
Lingual-Occlusal line angle reduction measurement
- 8mm
0. 6-1.0mm
What is a major difference between maxillary and mandibular preps?
Maxillary preps require a second plane of reduction on the buccal surface
1st - gingival crest to jnxn of and occlusal thirds
2nd - jnxn of middle and occlusal thirds to occlusal edge
What is the purpose of the first buccal plane on a maxillary prep?
It establishes the POW
What is the purpose of the second buccal plane on a maxillary prep?
Provides sufficient space for the restoration metal and restores the tooth to its original contour
Maxillary buccal second plane measurement
- 0mm
0. 8-1.0mm
