Class II prep and Slot Review

Question 1

What areas of the tooth are involved in a Class II prep?

Answer 1

the proximal surface of posterior teeth

Question 2

Where does the decay begin?

Answer 2

slightly gingival to the contact point

Question 3

What’s the best way to view the decay to know a Class II prep is necessary?

Answer 3

bitewing radiograph

Question 4

When should only the box or slot preparation be used?

Answer 4

when only the proximal is involved

Question 5

What is a compound or complex preparation?

Answer 5

one in which both the proximal and occlusal restoration are combined

Question 6

T/F. The position of the proximal box is DEPENDENT on the occlusal outline form.

Answer 6

FALSE! no no no.. theyre independent entitities

Question 7

How is the position of the box determined?

Answer 7

1. the tooth
2. the position of the tooth in the arch
3. the contact with the adjacent tooth
4. the extent of the decay

Question 8

T/F. A class II prep must begin with the occlusal outline first.

Answer 8

False. start with either the box or the occlusal outline and then blend together

Question 9

What are GV Blacks 7 principals of Cavity?

Answer 9

Outline Form
Resistance form
Convenience Form
Caries Removal
Finish Enamel Walls
Toilet Preparation

Question 10

What is the outline form for the Box Form of a Class II prep?

Answer 10

gingival floor:
must break contact
prep width dependent on extent of caries

Question 11

As you move from anterior to posterior, contact tends to move in a _____________ direction.

Answer 11

gingival

Question 12

What 5 criterion are used for Resistance Form of a Classs II Prep?

Answer 12

Adequate thickness of material pulpally (1.5 mm deep at least)
Axial depth is 1.5 mm in molars and 1 mm in premolars
No unsupported enamel
No sharp internal line angle
Flat Floors

Question 13

What aspects of Retention are needed?

Answer 13

Parallel or convergent walls of both occlusal and box portion
Retention grooves B-L in box

Question 14

Convenience form for Class II?

Answer 14

the shape or form allows adequate observation, accessibility, and ease of operating in removing carious dentin
*can be extended over areas of decay

Question 15

What degree should the exit angles be?

Answer 15

90 (butt joint) for strength of the amalgum

Question 16

What are the indications for a Slot Preparation?

Answer 16

• Class II caries which does not include closely approximating occlusal caries
• No previously existing occlusal restoration
  (if occlusal caries exists it will be included in the prep)

Question 17

What’s the Outline form of a slot prep?

Answer 17

• conserve tooth structure
• all faults should be included
• all margins should be placed in a position that will allow for good finishing of the margins of the restoration

Question 18

Why must contact be broken between the infected tooth and the adjacent tooth?

Answer 18

breaking the contact allows for carving and burnishing of margins during the placement procedures

Question 19

Damaging the proximal surface of the adjacent tooth makes it ______ times more likely to become carious than undamaged surfaces.

Answer 19

3x.. but damaged proximal surfaces occur >68% of the time soo you’re not alone

Question 20

T/F. In a slot prep, the resistance form calls for beveling.

Answer 20

FALSE. just a flat gingival floor thats smooth, NOT BEVELED, and unsupported enamel rods removed with enamel hatchet or gingival marginal trimmer

Question 21

What are some Retentive features of the slot prep?

Answer 21

• parallel or convergent walls
• retention grooves on B/L sides of axial wall located 0.2-0.5 mm inside DEJ in natural teeth
• creates dovetail effect
• retention grooves are deeper as gingival floor and shallower as they approach the occlusal surface

Question 22

What could be a result of Convenience form in the slot prep?

Answer 22

development of an occlusal component

but obvs convenience = access to remaining caries both visually and mechanically

Question 23

What’s the deal with a Tunnel Prep?

Answer 23

• not generally recommended
• Failure rate 33% GREATER than slot preps
• conserve tooth structure but may undermine enamel
• more successful when restored with composite than amalgam
  so basically they suck