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 Posterior
Tooth Restorations
In the preparation of posterior
teeth, even reduction of the anotomical form should occur.
General Observations
-
Provide enough room to allow
adequate strength for restorative material
-
Avoid sharp internal edges
and angles
-
Maintain shoulder preparation
with butt joint margins
-
Avoid undercuts
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 Preparation
Margins
A shoulder preparation margin
of 1mm at a 90 degree -110 degree angle must be completed.
Avoid tapered margins, feathered edges, or beveled shoulders.
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 Inlay
Restorations
The enamel surfaces created by
the preparation are generally sufficient for acid etching.
With flat cusps, a diverging preparation helps optimize the
acid etching of the enamel.
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 Proximal
Prepare proximal with 60 degree
- 80 degree cavosurface angles. Avoid thin walls or
narrow isthmuses.
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 Onlay
restorations
An onlay prep. is indicated when
the prep. margin is less than 0.5mm away from the cusp tip
or when the enamel is severely Undermined.
Cusp Reduction
Cusp reduction os 2.0mm is recomended.
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 Anterior
Tooth Restorations
In the preparation of anterior
teeth, even reduction of the anatomical form must occur.
General Observation
-
Provide enough room to allow
adequate strength for restorative material
-
Avoid sharp internal edges
and angles
-
Maintain shoulder preparation
with butt joint margins
-
Avoid undercuts
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 Veneer
Restorations
In the preparation of veneer remember:
-
Veneer thickness approximately
0.6mm minimum
-
Provide a deep chamber at
the gingival margin
In stress bearing areas reduce
tooth surface to provide bulk of ceramic for function
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