Class 1 Occlusal Amalgam Restoration; Class 2 prep

Question 1

What would be the cause for placing a liner or base while prepping an occlusal amalgam?

Answer 1

Deep caries

Question 2

Life or Dycal

Answer 2

Calcium Hydroxide Liners

Question 3

T/F: do not place a base or a liner near the margins of the tooth

Answer 3

true

Question 4

The school does not teach using dentin desensitizers, but in what case may one be used?

Answer 4

Occasionally, after consultation with faculty, one might use Glumma on an especially sensitive tooth, but place a liner or base first in deep preparations.

Question 5

Types of desensitizers under amalgams:

Answer 5

Copal resin (Ex.: Copalite).

Unfilled, dentin bonded resins (Ex.: PQ-1, Peak)

Gluteraldehyde

Question 6

What are the advantages and disadvantages of copal resin

Answer 6

Advantage: inexpensive, quick to use

Disadvantage: leaves a film thickness
could wash out, causing microleakage

Question 7

What are the advantages and disadvantages of Unfilled, dentin bonded resins?

Answer 7

Advantage: intermediate in cost

Disadvantage:  some require more
than one step;  all involve some
form of etching with an acid, which
researchers suggest may leave
teeth more vulnerable to recurrent
caries.  Leave a film thickness.

Question 8

What are the advantages and disadvantages of gluma

Answer 8

Advantages: no film
thickness, one step to apply

Disadvantages: EXPENSIVE,
somewhat caustic to soft tissues & possibly to the pulp in deep preparations.

Question 9

If the patients occlude and there is a high spot what can be done to correct this??

Answer 9

Use the discoid carver to remove high
occlusion marks and inclined plane
contacts.

Question 10

Which kind of interproximal caries do not typically need to be restored??

Answer 10

Initial (previously called “incipient”) Caries–not usually restored

Question 11

Which age demographic is root caries more common in??

Answer 11

older patients after gingival recession

Question 12

is the axial wall of a class II amalgam convex or concave?

Answer 12

convex

Question 13

What is the buccal contact clearance around a class II amalgam box

Answer 13

Open .2–.5 mm.

Question 14

What is the lingual contact clearance around a class II amalgam box

Answer 14

Open .2–.5 mm.

Question 15

What is the gingival contact clearance around a class II amalgam box

Answer 15

Gingival Contact is Open at Least .5 mm. to Get Out of the Etched, Caries-Susceptible Area Below the Contact Area Itself.

Question 16

What does the reverses-S Curve accomplish??

Answer 16

1. It creates a smoothly rounded outline form that improves resistance to amalgam fracture.
2. It keeps the narrowest part of the prep. away from the axiopulpal line angle (the two areas where amalgam fracture is most likely)
3. It allows the preparation to break contact
   on the buccal
   side of the box, but also allows the buccal wall to meet the tooth surface at a 90˚ cavosurface angle

Question 17

What are the three objectives of a class II prep

Answer 17

1. Include all caries & defects. Remove existing
   restorative material & undermined enamel.
2. Create 90˚ cavosurface margins on all box
   walls.
3. Ideally, when possible, create no more than
   .5 mm. clearance with adjacent proximal
   surface facially, lingually, and gingivally.

Question 18

What are the purposes of retention grooves??

Answer 18

To retain the amalgam segment that fills the box against INTERPROXIMAL displacement

Question 19

the long axis of the crown of the mandibular first premolar tilts _______.

Answer 19

lingually.

Question 20

Undermined Enamel

Incorrect Axis of entry

Incorrect Reverse-S Curve

Undermined Enamel on Gingival Margin

Retention Grooves Misplaced

Concave Axial Wall

Answer 20

COMMON ERRORS ON CLASS II AMALGAMS