Quiz 1 Flashcards
adaption
the degree of fit between a prosthesis and supporting structures
axial inclination
the alignment of the long axis of a tooth to a selected plane, often the horizontal plane
axis preparation
the planned line or path of placement and removal for a dental restoration
bevel
- a slanting edge
- the process of slanting the finish line and curve of a tooth preparation
bur
a steel or tungsten carbide rotary cutting instrument
bur head
the cutting portion of a dental bur
bur head length
the axial dimension of the bur head
bur head shape
the geometrical outline form of the cutting surface edges, usually described successively by proximity from the shank to the tip end
bur shank
that component of the dental bur which fits into the head piece
butt
to bring any two flat-ended surfaces into contact without overlapping, as in a butt joint
chamfer
a finish line design for tooth preparation in which the gingival aspect meets the external axial surface at an obtuse angle
chamfer angle
the angle between a chamfered surface and one of the original surfaces from which the chamfer is cut
clearance
a condition in which bodies may pass each other without hindrance
clinicial crown
the portion of a tooth that extents from the occlusal table or incisal edge to the free gingival margin
complete crown
restoration that covers all the coronal tooth surfaces
convergence angle
- the taper of a crown preparation
- Recommended range 2-10 degrees
- ideal 6 degrees
crown
- the highest portion of a tooth occlusal to the dentioenamel junction or artificial substitute for this
- to place a crown on a tooth, dental implant or tooth substitute
deformation
the change of form or shape of an object
dentin
a calcareous material similar to but harder and denser than bone that comprises that principle mass of the tooth
divergence
the reverse taper of walls or a preparation for a restoration
divergence angle
the sum of the angles of taper of opposing walls of a tooth preparation that diverge away from each other
draw
the taper or convergence of walls of a preparation for a restoration
extracoronal
that which is outside or external to, the crown proportion of a natural tooth
extracoronal retainer
that part of a fixed dental prosthesis uniting the abutment of the other elements of a prosthesis that surrounds all or part of the prepared crown
finish line
the terminal portion of the prepared tooth
fit
the adaptation of any dental restoration to its site, in the mouth
groove
a narrow channel or depression, such as the indentation between tooth cusp or the retentive features placed on tooth surfaces to augment the retentive characteristics of crown preparations
interocclusal clearance
the amount of reduction achieved during tooth preparation to provide for an adequate thickness of restorative material
line angle
the point of convergence of two planes in a cavity preparation
lingual inclination
deviation of the coronal portion of a tooth from the vertical plane toward the tongue
long axis
a theoretical line passing lengthwise through the center of a body
margin
the outer edge of a crown, inlay, onlay or other restoration. The boundary surface of a tooth preparation and/or restoration is termed the finish line
path of placement (POW)
the specific direction in which a prosthesis is placed on the abutment teeth or dental implants
point angle
in the development of a cavity preparation, that place of convergence of three planes or surface
retention
that quality inherent in the prosthesis acting to resist the forces of dislodgment along the path of placement
retention arm
an extension that is part of a removable dental prosthesis and is used to aid in the fixation of the prosthesis; a part of a clasp
retention form
the features of a tooth preparation that resists dislodgment of a crown in a vertical direction or along the path of placement
shoulder finish line
a finish line designed for tooth preparation in which the gingival floor meets the external axial surfaces at approximately a right angle
supragingival
that portion of a natural or artificial tooth that is coronal to the gingival crest
taper
the convergence of two opposing external walls of a tooth preparation as viewed in a given plane
undercut
any irregularity in the wall of a prepared tooth that prevents the withdrawal or seating of a wax pattern or casting
veneer
a thin sheet of material usually used as a finish
Fixed prosthodontics
fixed prosthodontic treatment involves the replacement and restoration of teeth by artificial substitutes that are not readily removable from the mouth
patiente selection
- chief complain
- communication
- dental history
- medical history
- palpation
- percussion
- periodontal examination
- systemic conditions
- (TMJ) temporomandibular joint dyfunction
What are the principles of tooth preparation
1) biological consideration
2) mechanical consideration
3) esthetic consideration
Things to consider during tooth preparation that affect future dental health
- axial reduction
- margins
- occlusal considerations
- preventing tooth fractures
Mechanical considerations of tooth preparation
1) providing resistance from
2) providing retention form
3) preventing deformation of the restoration
How do you provide resistance form
a. magnitude and direction of the dislodging forces
b. geometry of the tooth preparation
c. physical properties of the luting agent
How do you provide retention form
1) magnitude of the dislodging forces
2) geometry of the tooth preparation
3) roughness of the fitting surface of the restoration
4) materials being cemented
5) film thickness of the luting agent
How do you prevent deformation of the restoration
1) alloy selection
2) adequate tooth reduction
3) margin design
What are the types of crown
CVC- complete veneer crown
MCC- metal ceramic crown
ACC- All ceramic crown
Zirconia
What is a CVC
a cast-gold extracoronal restoration which covers the clinical crown
Preparation
the final shape of the tooth produced by instrumentation to receive a restoration
Complete veneer crown preparation
extracoronal preparation involving the entire clinical crown
What are the indications that a crown is needed
1) extensive coronal destruction
2) short clinical crowns
3) endodontically treated teeth
4) maximum retention and resistance are needed
5) correction of axial contours
What are the contraindications of a crown
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
What are the advantages of using a complete veneer crown
- high strength
- good retentive qualities
What are the disadvantage of using a complete veneer crown
- removal of large amount of tooth structure
- adverse effects on tissue
- display of metal
- vitality testing not feasable
What are the sequence of steps of complete veneer crowns
- occlusal guide grooves
- occlusal reduction
- axial guide grooves
- axial reduction( Buccal and Lingual)
- axial reduction (Interproximal)
- finishing and evaluation
What is the recommended dimensions
central groove: 1.0mm
functional cusp: 1.5mm
non-functional cusp: 1.0mm
chamfer width: 0.5mm
Advantages and disadvantages of having a chamfer
advantage: distinct margin, adequate bulk, easier to control
disadvantage: care needed to avoid unsupported lip of enamel
What should the final preparation provide
- ideal retention form
- ideal resistance form
- maximum conservation of tooth structure
