6. Class II Amalgam Preparation Flashcards
Class II Lesion
Found on the ____ surfaces of ____ teeth (sides of teeth)
____ surface cavity
Found mesially and distally usually just below the ____
(where the teeth touch each other)
proximal
posterior
smooth
contact points
Classification by Surface \_\_\_\_ surface Take the name of both surfaces Examples Mesio-occlusal (MO) Disto-occlusal (DO)
Classification by Complexity
____
Prepared cavities
that involve ____ tooth surfaces
two
compound
two
Begins with a broad decalcification of enamel
See a ____ of decay progressing through enamel towards dentin on an x-ray
At DEJ, decay spreads out then forms a ____ of decay towards the pulp
Cones of decay are ____ to ____ at DEJ
Once the lesion reaches dentin, it flares at the DEJ
Proximal surface is still intact
Only see lesion on an ____
Eventually the surface breaks down and explorer can penetrate
Then, the lesion progresses toward pulp
cone cone apex base x-ray
Clinical appearance
May not have a clincal appearance, or
____ over the marginal ridge if the cavity has progressed and undermined the enamel
opacity
Noncavitated: \_\_\_\_ intact \_\_\_\_ of proximal surface may be present Superficial radiolucency may be present Marginal ridge is not \_\_\_\_
■ Cavitated: Surface broken, detected visually or possibly tactilely Marginal ridge may be discolored /shadow \_\_\_\_ area in dentin on transillumination Radiolucency is present beyond the \_\_\_\_
surface opacity discolored opaque DEJ
Class II Preparation
Considerations:
An extension of Class I
Occlusal surface is normally included Convenience form
Extension for prevention
Lesion is removed by creating a box shaped preparation around the caries
Anatomic Considerations: Some areas are not included in the preparation:
Intact ____ on maxillary molars are not normally included in the preparation outline
This is avoided because the ____ of the crown is significantly greater when this ridge is left intact
oblique ridges
strength
____ in the mandibular first premolars do not usually have a deep connecting fissure between the mesial and distal pits and not normally included in the preparation to avoid weakening the small lingual cusp
Some cases may be limited to a proximal
box preparation only – ____ PREP (usually for ____ preparations)
transverse
slot
composite
B and G: ____ to occlusal table and ____ to long axis of the tooth)
P and A: ____ external surface and pulpal chamber and ____ to long axis of the tooth
parallel
perpendicular
parallel
perpendicular
Class II Outline Forms
Man First Premolar
When preparing, tilt bur slightly ____ to establish correct pulpal wall direction
Pulpal wall will slope ____
Gingival wall is ____ to long axis of tooth
lingually
occlusally
perpendicular
Class II Outline Forms
Max/Man Premolars
Finished outline form including the ____, lingual extension (mand ____) , proximal box and ____ curve
Man Molars
Finished outline form including the buccal and lingual extensions, proximal box reverse S curve
No ____
dovetail
2nd
reverse S
dovetail
Class II Outline Forms
Max Molars
Due to oblique ridge
MO: Only mesial portion of occlusal surface is included
DO: Only distal portion of the tooth is involved
If oblique ridge is undermined, then ____
If distal caries and undermined oblique ridge, then ____ cavity will be prepared
If the oblique ridge is undermined, and the lingual groove has caries, then continue through ____ and ____
continue
MOD
ridge
groove
Principles of cavity design and preparation
External Outline Form Part I - Occlusal As in Class I Outline:
All carious ____
All ____ enamel
All ____ enamel
Molar Occlusal Outline: Extend into the major developmental grooves ____mm
pits and fissures
decalcified
undermined
1
External Outline Form - Occlusal
Try to keep isthmus width equal to or less than ____ the distance between the cuspal line angles
Occlusal Preparation
As in Class I Outline: Use 330 bur
____ mm into dentin (____ in the shallowest area)
Pulpal floor flat, smooth, and level
1/4
- 5
- 5
Principles of cavity design and preparation
External Outline Form Part II - Proximal
Opening is extended buccolingually and gingivally with 330 bur. As the box area deepens beyond depth of 330 bur, switch to the 245 bur.
____ motion
Proximal portion will be wider buccolingually at the ____ level and narrower at occlusal portion (retention)
A wooden wedge can be placed gingival to contact area:
Slightly opens the interproximal space and aids in preventing damage to the adjacent teeth
Aids in preventing injury to soft tissues *Also can place a matix band interproximally
pendulum
gingival
Proximal box placement and size is dictated by the ____
Clearance between the teeth is ____ mm, measured with the tip of the explorer along the entire buccal, lingual and gingival walls of the box
contact
0.5