ALL-CERAMIC CROWNS
Indications
• When high esthetic requirement is considered
and no other conservative restoration is
indicated.
• Considerable proximal or facial caries that can
no longer be restored by composite resin.
• In case of intact incisal edge
• Favourable distribution of occlusal load
• For fractured anterior teeth not involving
more than 1/3rd of inciso gingival length.
• Discoloured anterior teeth due to trauma or
root canal treatment.
• Malformed teeth due to developmental
defects.
• Malposed or rotated teeth.
Contraindications
•
•
•
•
•
•
When superior strength is warranted and metalceramic crown is more appropriate.
Significant caries with insufficient coronal tooth
structure for support .
Short clinical crowns.
Thin
teeth
faciolingually
or
constricted
circumference.
Unfavourable distribution of occlusal load.
eg:- edge to edge bite relationship
deep bite cases
In young patients with large vital pulp.
• Individuals involved in sports or rigorous
occupations where there are high risks of
fractures.
• Individuals having bad habits like BRUXISM.
• Patients with periodontal surgery or cervical
erosion.
Advantages
•
•
•
•
•
•
Excellent esthetics
Good tissue response even for subgingival
margins.
Slightly more conservative of facial wall than
metal ceramic
Restores functions and gives maximum
retention.
High color stability and low conductivity.
Can be used as single restoration only.
Disadvantages:
•
•
•
•
•
Reduced strength compared to metal
ceramic crown.
Proper preparation extremely critical
Among least conservative preparations
Brittle nature of material
Wear has been noticed on functional
surfaces of natural teeth that oppose
porcelain restorations.
ARMAMENTARIUM FOR TOOTH
PREPARATION
• ROUND END TAPERED DIAMOND
STONE(0.8mm)
• FLAT END TAPERED DIAMOND STONE (1mm)
• WHEEL OR FOOT BALL DIAMOND STONE
• FINISHING STONES AND CARBIDE BURS
• BINANGLE CHISEL
Depth orientation grooves bur
PORCELAIN JACKET CROWN
PREPARATION
• Depth orientation grooves: A
flat end tapered diamond is
first aligned with the incisal
portion of the facial surface and
two vertical cuts are made to
the full diameter of the
diamond, fading out at the
“break” where the curvature of
the facial surface is the
greatest. Three similar grooves
are made maintaining the same
instrument parallel to the
gingival segment of the facial
surface. Two incisal orientation
grooves 2.0 mm deep are
made.
• Facial reduction, incisal
half: A flat end tapered
diamond is used to
remove the tooth
structure remaining
between the orientation
groove in the incisal
portion of the facial
surface.
• Facial reduction, gingival
half: A flat end tapered
diamond is used to
reduce the gingival
segment and extend well
into the proximal
surface. Extend the facial
reduction through the
proximal surfaces with
the flat end tapered
diamond producing a
shoulder in the process.
• Lingual reduction: A
small round diamond with
a head 1.4 mm in
diameter is used to make
four depth orientation
cuts. A small round wheel
diamond is used to create
a concave surface over
the lingual surface of the
tooth incisal to the
cingulum.
• Lingual axial
reduction: A flat end
tapered diamond is
employed for axial
reduction to prepare
the vertical lingual
wall. Blend the
reduction of each axial
surface with that on
the adjacent axial
surface.
Axial finishing: No:
171 bur(carbide) is
used to smooth the
axial surfaces and to
round
all distinct
positive angles on the
preparation.
• Shoulder finishing: No:
957 bur(end cutting
bur) is used for
preparing a smoothly
cut shoulder
perpendicular to the
line of force or to the
long axis of the tooth.
The features of all ceramic crowns preparation for a
porcelain jacket crown on an anterior tooth and the
function served by each.
List of burs
•
•
•
•
•
TF-13 Incisal and facial reduction
TC-11 proximal reduction
Foot ball – FO 25
2mm round bur
Finishing TF-13EF