Class III and V Composite Preparations Flashcards
(55 cards)
What is a class three prep?
interproximal areas in the anteriors
What is the first part of a class III pre-prep?
Clean the tooth!
◦ Pumice slurry
◦ Consepsis
◦ CHX
◦ No emollients that would affect bond
When should you select the shade of composite?
before placing the rubber dam
- dehydrating the tooth affects the shade
What do you do if you are unsure of what shade of composite to use?
Cure small blob of composite on tooth to check shade
- don’t etch and bond and the composite will flick off
What are the three color esthetic zones of the tooth?
- gingival = opaque
- middle = blend of incisal and gingival
- incisal = translucent
TAKE SHADE FROM PORTION OF SHADE GUIDE THAT IS…
MOST SIMILAR TO THICKNESS OF RESTORATION
When should you mark occlusion?
before applying the rubber dam
What is the shape of the class III prep?
wedge shape
Avoid margins of prep ending in…
occlusal contact areas
Where are the caries for a class III prep?
◦ Usually more lingual than facial
◦ Gingival to contact area
Where should you approach from doing a class III prep?
lingual
Why do you approach from the lingual on a class III prep?
◦ Caries tend to be more lingual
◦ Esthetics improved
◦ Discoloration and deterioration is less visible
◦ Color match is easier
◦ Facial enamel is conserved
◦ May be acceptable to leave unsupported enamel on facial and incisal wall of prep
Do you drill the incisal edge for a class III prep?
NO, Preserve incisal contact
◦ It may be acceptable to leave sound undermined enamel here
How should you do a class III prep?
Begin outline form
◦ Prepare PERPENDICULAR to long axis
Inciso-gingival height
◦ 1.5 on maxillary lateral
◦ 2.0 on maxillary central
Mesial distal width
◦ 1.0 on maxillary lateral
◦ 1.5 on maxillary central
Gingival contact is broken
Incisal contact is intact
For a class III prep you enter _________ to the long axis of the tooth
perpendicular
What should the inciso-gingival height be for the class III prep?
◦ 1.5 on maxillary lateral
◦ 2.0 on maxillary central
What should the mesial distal width be for the class III prep?
◦ 1.0 on maxillary lateral
◦ 1.5 on maxillary central
Where is the incisal point retention for a class III prep?
incisal portion of prep
- place with a 1/2 or 1/4 round
Where is the gingival groove retention for a class III prep?
at the gingival-axis line angle
- place with a 1/2 or 1/4 round
How deep are the retention points/grooves for the class III prep?
◦ Place point and groove where they would be in an ideal prep (even if the prep is deep)
Where do you bevel for a class III prep?
gingival and lingual boxes
◦ Place 1mm bevel lingual (or facial)
◦ 45 degrees
◦ Smooth, even
◦ Flame-shaped diamond bur
How much contact to you break facially?
minimally
If you would have heavy contact on the margin of a class III prep what can you do?
dovetail
- don’t bevel
◦ Enamel wears better than composite
◦ Enamel is stronger than composite
What do you do if caries are on the facial for a class III prep?
◦ Facial approach
◦ When lingual access may involve only centric contact of tooth
◦ Irregular tooth alignment or rotation
◦ Extensive caries on the facial
◦ Existing defective restoration on the facial
