Class II prep and Slot Review Flashcards
What areas of the tooth are involved in a Class II prep?
the proximal surface of posterior teeth
Where does the decay begin?
slightly gingival to the contact point
What’s the best way to view the decay to know a Class II prep is necessary?
bitewing radiograph
When should only the box or slot preparation be used?
when only the proximal is involved
What is a compound or complex preparation?
one in which both the proximal and occlusal restoration are combined
T/F. The position of the proximal box is DEPENDENT on the occlusal outline form.
FALSE! no no no.. theyre independent entitities
How is the position of the box determined?
- the tooth
- the position of the tooth in the arch
- the contact with the adjacent tooth
- the extent of the decay
T/F. A class II prep must begin with the occlusal outline first.
False. start with either the box or the occlusal outline and then blend together
What are GV Blacks 7 principals of Cavity?
Outline Form Resistance form Convenience Form Caries Removal Finish Enamel Walls Toilet Preparation
What is the outline form for the Box Form of a Class II prep?
gingival floor:
must break contact
prep width dependent on extent of caries
As you move from anterior to posterior, contact tends to move in a _____________ direction.
gingival
What 5 criterion are used for Resistance Form of a Classs II Prep?
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
What aspects of Retention are needed?
Parallel or convergent walls of both occlusal and box portion
Retention grooves B-L in box
Convenience form for Class II?
the shape or form allows adequate observation, accessibility, and ease of operating in removing carious dentin
*can be extended over areas of decay
What degree should the exit angles be?
90 (butt joint) for strength of the amalgum
What are the indications for a Slot Preparation?
- 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)
What’s the Outline form of a slot prep?
- 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
Why must contact be broken between the infected tooth and the adjacent tooth?
breaking the contact allows for carving and burnishing of margins during the placement procedures
Damaging the proximal surface of the adjacent tooth makes it ______ times more likely to become carious than undamaged surfaces.
3x.. but damaged proximal surfaces occur >68% of the time soo you’re not alone
T/F. In a slot prep, the resistance form calls for beveling.
FALSE. just a flat gingival floor thats smooth, NOT BEVELED, and unsupported enamel rods removed with enamel hatchet or gingival marginal trimmer
What are some Retentive features of the slot prep?
- 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
What could be a result of Convenience form in the slot prep?
development of an occlusal component
but obvs convenience = access to remaining caries both visually and mechanically
What’s the deal with a Tunnel Prep?
- 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
