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27 Cards in this Set
- Front
- Back
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other names for full crown prep
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full veneer crown prep
cast crown full metal crown |
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functional cusp bevel
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structural durability
this is occlusal reduction around edge |
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planar occlusal reduction
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structural durability
is done on occlusal table |
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axial reduction
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retention and resistance
is reduction down to finish line of prep |
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why do a full cast crown
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-predictable resorative outcome
-average lifespan of 7-10 years -high resistance and retention values, when compared to partial veneer |
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what are the indications to create a full cast crown
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-used on teeth that need maximum retention
-functional cusp fracture -retainer for FPD (fixed pros. denture) -non esthetic zone -axial surface has caries -existing restoration involves four or more tooth surfaces |
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restoration variations
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-all metal
-metal ceramic -all ceramic the reduction amounts vary, more for ceramic less for metal |
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depth groove placement
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-along the incline planes
-bur is perpidicular to long axis of tooth -not on crest of ridges -reduce only 1.0 on guiding -reduce 1.5 on supporting |
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finish line
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1.0 mm above the hard gingiva and 1.0mm in axial removal
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criteria for good evaluation of crown prep
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-smooth and uniform
-occlusal reduction varified with ball reduction -evaluate for undercuts (make sure there are no over hangs) |
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purpose of seating groove (these are not done in class)
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-provide resistance and retention
-orients the provisional |
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factors related to design and material selection for restoration
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-destruction of tooth surface
-esthetics -plaque control -financial considerations -retention |
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considerations for destruction of tooth surface
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-extent of decay
-cusp fracture |
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esthetic considerations
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-visibility of tooth
-patient expectations -can dentist achieve desired cosmetics -can be partial or full veneer -can be metal or ceramic |
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plaques control considerations
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-contour should allow for cleaning and increases sucess
-patient motivation to brush |
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What are the components of the PFM restoration
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Metal copinq
Porcelain veneer |
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three steps to masking a metal coping
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Opaque layer
Body layer Incisal layer |
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Characterization of metal coping
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craze lines
interproximal shading .5 to .3 mm thick |
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The incisal reduction for the anterior PFM preparation follows
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lingual apical slope
Parallel to the former incisal edge |
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The lingual reduction for the anterior PFM preparaticn is
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Should be 1.5 mm
This wall should be parallel to the gingival aspect of the axiofacial wall |
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transition area
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This is where the bevel of the shoulder finish line joins the chamfer
Location is lingual to the proximal contact |
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features of anterior pfm
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-Two plane axiofacial reduction (incisal/gingival)
-Shoulder bevel facial finish line (1.5 mm) -Chamfer lingual finish line (1.0 mm) -Planar incisal reduction (1-1.5mm) |
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posterior PFM occlusal reduction
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1.5 to 2.0
reduction is parallel to the occlusal plane |
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posterior pfm axial reduction
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1.5 - 2.0
facial bevel on shoulder finish line is placed at a 45 degree angle |
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posterior pfm lingual reduction
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1
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transition in posterior PFM
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is variable based on desired contact design
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reduction for ceramic prep
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2mm all around
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