Lab 7/8: Class II

Question 1

accepted Class II terminology

Answer 1

extending into proximal, extending gingivally, preparing a proximal box

Question 2

if Bu/Li walls were any angle but vertical, forces of occlusion would extend ____; lead to _____

Answer 2

laterally, possible fracture over time

Question 3

gingival seat is ____ to long axis of tooth

Answer 3

perpendicular

Question 4

proximal box must clear adjacent tooth by ___mm for reasons of ____

Answer 4

0.5mm, access

Question 5

term M-D dimension of proximal box

Answer 5

proximal depth

Question 6

ideal proximal depth on premolar teeth

Answer 6

1-1.25mm

Question 7

depth into dentin in ideal tooth

Answer 7

0.5mm into dentin

Question 8

ideal proximal depth on molar teeth

Answer 8

1.25-1.5mm

Question 9

axial wall should ___ ______ of tooth B-L in order to ___

Answer 9

parallel curvature, protect pulp

Question 10

axio-pulpal line angle should be _____ to prevent _____

Answer 10

rounded/beveled, fracture

Question 11

enamel of gingival seat should be _____

Answer 11

planed downward at margin

Question 12

In Class II preparation, only __ (__ or __) wall will be convergent (not ___). which one do you pick?

Answer 12

one, (Bu or Li), not both; pick the functional cusp

Question 13

having two proximal walls convergent ___ adjacent tooth structure

Answer 13

weakens

Question 14

functional cusps on Mx

Answer 14

Li

Question 15

functional cusps on Mn

Answer 15

Bu

Question 16

degree of convergence

Answer 16

6 degrees (same as Class I and V)

Question 17

angle of proximal cavosurface needs to be between…

Answer 17

90-110 degrees // 70-90

Question 18

proximal retention grooves placed _____ walls ___mm deep to DEJ

Answer 18

Bu and Li; 0.5mm

Question 19

what does the retention groove follow in Class II prep, the axial wall or DEJ?

Answer 19

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)

Question 20

do proximal contacts provide retention?

Answer 20

no

Question 21

retention groove extends ____

Answer 21

laterally

Question 22

retention groove is deeper _____, then fades

Answer 22

gingivally, fades

Question 23

term for: smooth, flowing outline form

Answer 23

regular

Question 24

term for : clear to the eye

Answer 24

defined

Question 25

term for: no unsupported enamel or weak tooth structure

Answer 25

well-supported

Question 26

purpose of S-curve in Class II prep

Answer 26

preserve triangular ridge of MBu cusp