Fixed lecture 1 Flashcards
Considerations Affecting Future Dental Health
Axial reduction
Margins
Occlusal considerations
Preventing tooth fractures
Biologic considerations,
which affect the health of the oral tissues.
Mechanical considerations,
which affect the integrity and durability of the restoration.
Esthetic considerations,
which affect the appearance of the patient
luting agent
Cement to maintain
CVC
complete veneer crown
MCC
metal ceramic crown
ACC
all ceramic crown
Zirconia
metal, looks nice.
CVC indications
- Extensive coronal destruction.
- Short clinical crowns 3.Endodontically treated teeth.
- Maximum retention and resistance are needed.
- Correction of axial contours
CVC CONTRAINDICATIONS
1.Wherever an intact buccal or
lingual wall exists.
2. If less than maximum retention and resistance are needed.
3.If objectives can be met with a more conservative restoration.
PROS CVC
Because all axial surfaces of the tooth are included in the preparation, the complete cast crown has
greater retention than a more conservative restoration. Has greater resistance form than a partial coverage
restoration on the same tooth.
A complete cast crown allows the operator to
modify axial tooth contour as well as occlusal modification
CONS
Removal of tooth structure is extensive and can have adverse effects on the pulp and periodontium
Because of the proximity of the margin to the gingiva, it is not uncommon to see inflammation of gingival tissues.
After cementation, it is no longer feasible perform electric vitality testing of an abutment tooth.
Patients may object to the display of metal associated with complete cast crowns.
chamfer
a finish line design for tooth preparation in which the
gingival aspect meets the external axial surface at an obtuse angle.
finish line
the terminal portion of the prepared tooth.
axial inclination
the alignment of the long axis of a tooth to a selected plane, often the horizontal plane.
convergence angle
the taper of a crown preparation, the angle, measured in degrees, formed between opposing axial walls.
Convergence angle
The angle or taper formed by opposing axial walls
Recommended range 2°–10° Ideal 6 ° to optimize retention
path of placement or POW
the specific direction in which a prosthesis is placed on the abutment tooth or remove from it.
Should be nearly coincident with the tooth’s long axis
undercut
any irregularity in the wall of a prepared tooth that prevents the seating or removal of a casting - pretty much a wax casting gets deformed when removing it.
Opposing axial walls which do not converge occlusally
Sequence CVC
occlusal guide grooves occlusal reduction axial guide grooves axial reduction( Buccal and Lingual) axial reduction (Interproximal) finishing and evaluation
CVC Dimensions
Central groove = 1 mm
Functional cusp = 1.5 mm
Non-functional cusp = 1 mm
Chamfer width = 0.5 mm
Occlusal Guide Grooves
242.6M diamond bur in high speed handpiece
depth grooves are placed 0.2mm shallower than the intended tooth reduction to allow for smoothing
FUNCTIONAL cusp
buccal cusp in mandibular arch
lingual cusp in the maxillary arch