Class II

Question 1

estimated that ________% of ideal lesions affecting primary molars would go undetected w/o radiographs

Answer 1

75%

Question 2

internal line angles for CL II should be _______

Answer 2

rounded

Question 3

why is it crucial to center the prep on the central groove?

Answer 3

¤ Possible pulp exposure
¤Danger of removing too much of a cusp when approaching the proximal
¤ Compromise proximal box form by overextension of the buccal or lingual walls

Question 4

what should the isthmus width be for CL II?

Answer 4

1/3 the intercuspal distance

Question 5

axial wall should be no deeper than _________

Answer 5

pulpal floor

Question 6

to support condensation, the gingival wall must be as lease as wide as the diameter of the ________

Answer 6

330 bur (0.75mm)

Question 7

the gingival wall should be _________ to the long axis of the tooth

Answer 7

perpendicular

Question 8

gingival wall will be slightly __________ as a result of using a pear-shaped bur in a pendulum movement

Answer 8

concave

Question 9

The B/L walls of the box should __________

Answer 9

converge

Question 10

T/F a reverse curve is required on primary teeth as well as permanent teeth

Answer 10

false. b/c of the broad flat contact area and considerable convergence no reverse curve is prepared

Question 11

T/F you should bevel the axiopulpal line angle

Answer 11

False. no bevel

Question 12

T/F there shouldn’t be a cavosurface bevel

Answer 12

True

Question 13

T/F preps on primary molars should be the same whether resin or amalgam is used

Answer 13

true

Question 14

For what tooth (teeth ) are traditional MO preparations not recommended?

Answer 14

Traditional dogma holds that we do not do MO amalgam preps on first primary molars

Question 15

If the proximal lesion is so large that preparation of a Class II cavity would require extension of the proximal box too far B/L (undermining cusps) and axially (endangering the pulp) what do you do?

Answer 15

a crown is prescribed.

Question 16

T/F the floor of the box is equal depth the whole way through and flat

Answer 16

false the floor is not flat, but is equal depth

Question 17

Slot preps on primary teeth are __________

Answer 17

contraindicated

Question 18

what are the common failures of CL II primary restorations?

Answer 18

-fracture of the isthmus of a CL II
-marginal failure in proximal box area (due to excessive flare of the cavosurface margin)
-recurrent caries (failure to extend preparation adequately in a buccal, lingual, or gingival direction

Question 19

common errors of CL II primary preps?

Answer 19

̈ (A) Failure to extend into distal fossa
̈ (B) Failure to follow outline of cusps
̈ (C) Isthmus > 1/3
̈ (D) excessive flare
̈ (E) >90 degree
̈ (F) Gingival wall too deep axially
̈ (G) Axial wall not following external outline of tooth

Question 20

what are the dimensions of the spot welded matrix band?

Answer 20

5mm wide
0.05mm thick

Question 21

Seat spot welded band so that it extends ______mm gingival to the cavosurface margin

Answer 21

.5-1mm

Question 22

spot welded band should extend ________mm occlusally beyond the marginal ridge

Answer 22

.5-1mm

Question 23

T/F when using 2 class II’s next to each other you do 1 at a time

Answer 23

False. want to do them back to back

Question 24

describe the snowplow technique

Answer 24

¤ placement of composite paste in bulk over a thin layer
of uncured flowable composite
¤ injection of the composite paste over the top of the uncured flowable pushes the flowable composite toward the occlusal, gingival, and interproximal areas

Question 25

describe the bulk-fill

Answer 25

¤ decreases the possibility of voids between layers of composite as well as to decreases placement time ¤ Rationale: preparations in most primary teeth have a deepest point in the range of 4 mm and a small intercuspal distance