Lab 7/8: Class II Flashcards
accepted Class II terminology
extending into proximal, extending gingivally, preparing a proximal box
if Bu/Li walls were any angle but vertical, forces of occlusion would extend ____; lead to _____
laterally, possible fracture over time
gingival seat is ____ to long axis of tooth
perpendicular
proximal box must clear adjacent tooth by ___mm for reasons of ____
0.5mm, access
term M-D dimension of proximal box
proximal depth
ideal proximal depth on premolar teeth
1-1.25mm
depth into dentin in ideal tooth
0.5mm into dentin
ideal proximal depth on molar teeth
1.25-1.5mm
axial wall should ___ ______ of tooth B-L in order to ___
parallel curvature, protect pulp
axio-pulpal line angle should be _____ to prevent _____
rounded/beveled, fracture
enamel of gingival seat should be _____
planed downward at margin
In Class II preparation, only __ (__ or __) wall will be convergent (not ___). which one do you pick?
one, (Bu or Li), not both; pick the functional cusp
having two proximal walls convergent ___ adjacent tooth structure
weakens
functional cusps on Mx
Li
functional cusps on Mn
Bu
degree of convergence
6 degrees (same as Class I and V)
angle of proximal cavosurface needs to be between…
90-110 degrees // 70-90
proximal retention grooves placed _____ walls ___mm deep to DEJ
Bu and Li; 0.5mm
what does the retention groove follow in Class II prep, the axial wall or DEJ?
it follows the DEJ (say the axial is placed more interiorly to tooth due to decay, the retention groove doe not also go deeper; it stays at the DEJ)
do proximal contacts provide retention?
no
retention groove extends ____
laterally
retention groove is deeper _____, then fades
gingivally, fades
term for: smooth, flowing outline form
regular
term for : clear to the eye
defined
term for: no unsupported enamel or weak tooth structure
well-supported
purpose of S-curve in Class II prep
preserve triangular ridge of MBu cusp
