2. Definition
• full coverage restoration:
• A restoration that covers all the coronal tooth
surfaces ( mesial, distal,facial,lingual and
occlusal)
(GPT-8)
3. Introduction
• Complete crowns are also known as full veneer
crowns.
• Veneer is a thin covering
• A complete crown replaces lost tooth structure
and imparts structural support to the tooth.
• Types:
• All-metal
• All-ceramic
• Metal-ceramic
6. All metal posterior crown
• The complete cast crown can be used to rebuild a
single tooth or as a retainer for a fixed
prosthesis.
• Advantages:
• Has best longevity of all fixed restorations.
• Most effective retention and resistance
• Alteration in tooth form and occlusion.
8. • Indications:
• Extensive caries
• Defective restorations
• Endodontically treated teeth
• Retainer for long span FPD
• Contra indications:
• Poor oral hygiene
• Large pulp chambers
All metal posterior crown
9. Features of full veneer crown
preparation and functions served by
each
10. All- metal full veneer crown:
• Armamentarium:
• Handpiece
• Round end tapered diamond
• 171L bur
• Torpedo diamond
• Torpedo bur
• Short needle diamond
• Red utility wax
Torpedo carbide bur
11. Preparation of a putty index:
• Before tooth preparation putty index is made
•
• It serves as a guide & used for verification of
preparation
• Elastomeric impression material (base &
catalyst)
12. • procedure:
• half scoop base paste +half scoop catalyst paste
(kneaded)
• Adapted on tooth to be prepared & one adjacent
tooth on each side.
• Once index is set –cut into labial and lingual
half.
• Then tooth preparation is verified using index.
13. The features of a preparation for a
complete cast crown and the function
served by each
14. • Criteria for tooth reduction
• The occlusal reduction must allow adequate room
for the restorative material from which the cast
crown is to be fabricated.
• Minimum recommended clearance is 1 mm on
nonfunctional cusps and 1.5 mm
on functional cusps.
• The Functional Cusps: The Lingual
Upper and The Buccal Lower
• Non-Functional
Cusps: The Buccal Upper and The Lingual
Lower (BULL)
16. Occlusal reduction
• Depth:
• Function cusp – 1.5 mm
• Non functional cusp- 1 mm
•
• Rotary instrument: round end tapering
diamond and no 171 bur.
17. • Occlusal Depth orientation grooves are placed on the occlusal
surface with round end tapered diamond.
• place round end tapered diamond bur approx 1 mm deep in
central ,mesial , distal fossae and creating about 1.5 mm of
clearance on the functional cusps and 1 mm on non functional
cusps.
18. • Place depth orientation grooves in the buccal and lingual
developmental grooves and in each triangular ridge extending
from the cusp tip to the centre of its base.
19. • On the non functional cusp, the groove should parallel the
intented cuspal inclination, on the functional it should be
slightly flatter to ensure additional reduction of the functional
cusp.
20. • After completing occlusal reduction the clearance can be
checked by having the patient to close on a 2mm thick strip of
red utility wax.
21. • Complete the occlusal reduction in two steps.
• Half of the occlusal surface is reduced first so that other half
will be maintained as reference,
22. • Place depth orientation
grooves for a functional cusp
bevel across the facial occlusal
line angle of the mandibular
premolar or molar
.
23. • Round end tapered diamond is used to give bevel parallel to
inward facing inclines if opposing tooth to a depth of 1.5 mm ,
usually forming a 45 degree angle with the axial wall.
24. Alignment grooves for axial
reduction
• Facial axial reduction is
done with torpedo
diamond , producing a
definite chamfer finish
line.
25. • When grooves are placed be sure that the shank of the
diamond is parallel to the proposed path of withdrawl.
• When a diamond with a 6 degree taper is used, an ideal axial
reduction on the preparation wall will result.
26. • Gingivally the resulting depth of preparation
should be not more than half the width of the tip
of diamond otherwise a lip of unsupported
enamel will be created.
27. • While doing axial reduction cut into the
proximal area from both sides until a few mm of
interproximal area remains.
28. • Now a thin tapered diamond is worked through
the proximal area in an occlusogingival
buccolingual swaing motion ,carefully avoiding
the adjacent teeth.
29. • Once sufficient room is created the torpedo
diamond is introduced to plane the walls while
simultameously forming a chamfer as the inter
proximal gingival finish line.
30. • All the axial surfaces are
smoothened with a
torpedo carbide
finishing bur which will
also finish the chamfer
finish line.
Torpedo carbide bur
31. • The final step is the
placement of a seating groove
.(no. 171 bur)
• It will prevent the rotational
tendencies during
cementation and will help the
casting to guide in place.
35. • The metal-ceramic restoration, also called a
porcelain-fused-to-metal (PFM) restoration.
• such a restoration combines the strength and
accurate fit of a cast metal crown with the
cosmetic effect of a ceramic crown.
• With a metal substructure, metal-ceramic
restorations have greater strength.
36. • To be successful, a metal-ceramic crown
preparation requires more tooth reduction
wherever the metal substructure is to be
veneered with dental porcelain.
• The metal should be 0.3 to 0.5 mm thick if it is a
noble metal alloy, while a metal coping made of
the more rigid base metal alloys can be thinner to
0.2 mm.
37. • The metal coping in a metal-ceramic restoration is
covered with two or three layers of porcelain:
•
1. Opaque porcelain conceals the metal
underneath, initiates bonding between the ceramic
and the metal.
•
2. Body porcelain, or dentin, makes up the bulk of
the restoration, providing most of color or shade.
•
3. Incisal porcelain, or enamel, imparts
translucency to the restoration.
•
38. • Without the space for a sufficient thickness of
ceramic material, two things can happen:
• (1) The restoration will have poor contours.
• (2) The shade and translucency of the
restoration will not match adjacent natural
teeth.
40. Porcelain fused to metal crown
• Indications:
• Teeth where significant aesthetic demands are
placed.
• If all ceramic crown is contra indicated.
41. Contraindications
• Active caries or untreated periodontal disease.
• Large pulp chambers
• Where more conservative retainer is feasible.
42. • Advantages:
• Superior aesthetics as compared to cast metal
crowns
• Disadvantages:
• Require significant tooth reduction
• Subject to fracture
• Shade selection can be difficult
43. Posterior
Porcelain fused to metal crown
preparation.
• Armamentarium
• Lab knife with 25 no blade
• Silicon putty with acclerator
• Handpiece
• Flat end tapered diamond
• Short needle diamond
• Torpedo diamond
• Torpedop bur
• Radial fissure bur
• No.957 end cutting bur.(shoulder finishing)
44.
45. Steps: (posterior metal ceramic crown)
Planar occ reduction- round
end tapered diamond &
no.171 bur
Functional cusp bevel- round
end tapered diamond & no.
171 bur
Depth orientation grooves- flat
end tapered diamond
(1.6 dia shank)
Facial reduction (occlusal half )-flat end
tapered diamond
Facial reduction ( gingival half) – flat end
tapered diamond
46. Proximal axial reduction-
short needle diamond
Lingual reduction- torpedo
diamond (chamfer finish
line)
Axial finishing- torpedo
finishing bur & no 171 bur
Shoulder finishing- no 957 bur
47. Preparation
• Silicone putty is adapted to the facial, lingual
and occlusal surfaces of the tooth to be prepared.
49. Occusal reduction
• Round end tapered diamond is used to give
depth orientation grooves. In the areas of
ceramic coverage reduction should be 1.5 to 2
mm.
50. • Functional cusp bevel is provided on the lingual
inclines of the maxillary lingual cusps and facial
inclines of the mandibular facial cusps.
• The depth is 1.5 mm if covered by metal and 2
mm if veneered by porcelain.
51. Axial reduction
• Cut three vertical grooves in the occlusal portion
of the facial surface. These are placed with full
diameter of the instrument.
52. • Now align the bur parallel along the
gingival component and place atleast 2
more grooves near the line angles of
the tooth. The tip of the diamond
should be supra gingival at this time.
• Now remove the facial surface with
round end tapered diamond.
53. • If facial reduction is less than 1.2 mm for base
metal crown or 1.4 mm for a noble metal ceramic
crown…..
54. • Proximal axial reduction is begun with short
needle diamond
• Diamond is used in up and down motion on
facial and lingual aspect if interproximal tooth
structure.
• or it can be held horizontally on occlusal portion
with facio- lingual movement
55. • The lingual axial wall is reduced with a torpedo
diamond .
• To create a distinct chamfer finish line.
56. • The transition from a deeper facial reduction to the
relative shallower lingual reduction results in vertical wall
or “wing” of tooth structure.
• If wing is not lingual to proximal contact – inter-proximal
portion of facial porcelain will have lifeless appearance
• Wing provides torque resistance to the preparation.
57. • Finishing is done with -170 bur (axial , occlusal
finishing)
• End cutting bur (no 957 bur) – shoulder
finishing.
58. • Facial silicone and mid saggital silicone putty
index shows uniform reduction on the facial
surface and occlusogingivally.
59.
60. All ceramic crown
• Indications
• High esthetic requirement
• contraindications:
• Where more conservative restoration can be
used .
• In molar due to increased occlusal load.
61. • ADVANTAGES :
• Superior aesthetics
• DISADVANTAGES
• Reduced strength
• Less conservative
• Wear of opposing natural teeth
62. All ceramic crown tooth preparation
posterior.
• A combination of facial and lingual index is
made by adapting silicone putty to the facial ,
lingual and occlusal surface of posterior teeth.
• This will provide an accurate reference for both
facial and lingual reduction
63. Steps- (all ceramic posterior crown)
Occlusal reduction -
large round end tapered
diamond
Functional cusp bevel –
large round end tapered
diamond
68. • Reduction in one plane parallel with the cervical
plane may result in insufficient space of
porcelain in the incisal half and an over-
contoured restoration.
• One-plane reduction may come dangerously
close to the pulp.
69. • Anterior metal-ceramic crowns
preparation
• The labial reduction is carried out in two planes:
the gingival portion to parallel the long axis of
the tooth, the incisal portion to follow the
normal facial contour.
