Class 1 Occlusal Amalgam Restoration; Class 2 prep Flashcards
What would be the cause for placing a liner or base while prepping an occlusal amalgam?
Deep caries
Life or Dycal
Calcium Hydroxide Liners
T/F: do not place a base or a liner near the margins of the tooth
true
The school does not teach using dentin desensitizers, but in what case may one be used?
Occasionally, after consultation with faculty, one might use Glumma on an especially sensitive tooth, but place a liner or base first in deep preparations.
Types of desensitizers under amalgams:
Copal resin (Ex.: Copalite).
Unfilled, dentin bonded resins (Ex.: PQ-1, Peak)
Gluteraldehyde
What are the advantages and disadvantages of copal resin
Advantage: inexpensive, quick to use
Disadvantage: leaves a film thickness
could wash out, causing microleakage
What are the advantages and disadvantages of Unfilled, dentin bonded resins?
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.
What are the advantages and disadvantages of gluma
Advantages: no film
thickness, one step to apply
Disadvantages: EXPENSIVE,
somewhat caustic to soft tissues & possibly to the pulp in deep preparations.
If the patients occlude and there is a high spot what can be done to correct this??
Use the discoid carver to remove high
occlusion marks and inclined plane
contacts.
Which kind of interproximal caries do not typically need to be restored??
Initial (previously called “incipient”) Caries–not usually restored
Which age demographic is root caries more common in??
older patients after gingival recession
is the axial wall of a class II amalgam convex or concave?
convex
What is the buccal contact clearance around a class II amalgam box
Open .2–.5 mm.
What is the lingual contact clearance around a class II amalgam box
Open .2–.5 mm.
What is the gingival contact clearance around a class II amalgam box
Gingival Contact is Open at Least .5 mm. to Get Out of the Etched, Caries-Susceptible Area Below the Contact Area Itself.
What does the reverses-S Curve accomplish??
- It creates a smoothly rounded outline form that improves resistance to amalgam fracture.
- It keeps the narrowest part of the prep. away from the axiopulpal line angle (the two areas where amalgam fracture is most likely)
- 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
What are the three objectives of a class II prep
- Include all caries & defects. Remove existing
restorative material & undermined enamel. - Create 90˚ cavosurface margins on all box
walls. - Ideally, when possible, create no more than
.5 mm. clearance with adjacent proximal
surface facially, lingually, and gingivally.
What are the purposes of retention grooves??
To retain the amalgam segment that fills the box against INTERPROXIMAL displacement
the long axis of the crown of the mandibular first premolar tilts _______.
lingually.
Undermined Enamel
Incorrect Axis of entry
Incorrect Reverse-S Curve
Undermined Enamel on Gingival Margin
Retention Grooves Misplaced
Concave Axial Wall
COMMON ERRORS ON CLASS II AMALGAMS
