5.full metal crown

Dr. lama khaled El Banna

Faculty of Oral and Dental Medicine

Al – Azhar University
Fixed prosthodontic

1. FIXED PROSTHODONTIC I
Department of Endodontics Fixed
Prosthodontics

2. The complete cast Crown

3. 1. Indications, Contra-indications
2. Disadvantages and Advantages of Full Metal Crowns
3. Steps of Tooth preparation

4. Advantages
- The complete cast crown has greater retention than a
more conservative restoration on the same tooth.
- A complete cast crown preparation has greater
resistance from than a partial-coverage restoration on
the same tooth.
- The strength of a complete cast crown is superior to
that of other restorations.

5. Indications
- The complete cast crown is indicated on teeth that exhibit
extensive coronal destruction by caries or trauma.
- It is the restoration of choice whenever maximum retention and
resistance are needed.
- On short clinical crowns or when high displacement forces are
anticipated.
- The complete cast crown is indicated on endodontically treated
teeth. Its superior strength compensates for the loss of tooth
structure that results from previous restorations, carious lesions,
and endodontic access.
- The restoration also may be used to support a removable partial
denture.

7. Contraindications
- The complete cast crown is contraindicated if
treatment objectives can be met with a more
conservative restoration.
- A complete crown is not indicated. If a high
esthetic need exists ( e.g., anterior teeth(.

8. Preparation Steps
The clinical procedure to prepare a tooth for a
complete cast crown consists of the following
steps:
- Guiding grooves
- Occlusal reduction
- Axial reduction
- Finishing

9. Recommended dimensions for a complete cast crown. On functional cusps (buccal
mandibular and palatal maxillary( the occlusal clearance should be equal to or greater
than 1.5 mm. On nonfunctional cusps, a clearance of at least 1 mm is needed. The
chamfer should allow for approximately 0.5 mm of metal thickness at the margin.
The functional (Centric( cusp bevel will be placed at about 45 degrees to the long axis.

10. Visualize
Outer Contour
Before Cutting Preparation

18. Depth orientation grooves are placed on the occlusal surface with round end tapered
diamond or with Round diamond wheels.

19. The use of guiding grooves for occlusal reduction is helpful only if the tooth is in good
occlusal relationship before preparation.

20. Guiding grooves are placed on the occlusal surface. They are deeper on the functional
cusp, and for the functional cusp bevel they diminish in depth from the cusp tip to the
cervical margin.

21. The exact number of guiding grooves is vary

22. Reduction parallels opposing triangular ridges
Correct depth (0.8 mm for the central groove and nonfunctional cusps, 1.3 mm for the
functional cusps(.

24. OCCLUSAL REDUCTION
1.5 mm of clearance of functional cusp and at least 1.0 mm on the nonfunctional cusp.

25. After the guiding grooves are placed, the occlusal reduction is performed.

26. Half the occlusal surface is reduced first so that the other half can be maintained as a
reference.

35. Measure clearance with RGS 3
Instrument fits loosely

40. Evaluation of the adequacy of occlusal
clearance. A, The patient closes into softened
wax / silicon. B, The thickness of the wax /
silicon is assessed visually and measured
with a caliper after it has been removed from
the mouth.
A
B

41. Axial Reduction & Chamfer
- Axial walls at least 3 mm long.
- 3-6 degree taper between opposing walls.
- Chamfer depth from 0.3-0.7 mm.
- Follow gingival contours.
- Finish line 0.5 mm supragingival.

42. Line Of Draw
- IMAGINARY line
- BEFORE preparation is begun
- CENTER of all possible paths of
withdrawal or seating of the restoration

46. Interproximal Reduction
- Extend below adjacent tooth contact
- Avoid
- Adjacent tooth damage
- Overtapering
- Excessive axial reduction
Initial proximal axial reduction
with short needle diamond
followed by the round-end
tapered diamond.

48. Place the cervical chamfer concurrently with axial reduction. Its width should be
approximately 0.5 mm, which will allow adequate bulk of metal at the margin. This
chamfer must be smooth and continuous mesiodistally.

60. Non Functional Cusp Bevel
0.2-0.3 mm wide

66. The completed preparation is characterized by a smooth, even
chamfer; a 6-degree taper; and gradual transitions between all
prepared surfaces.

67. Exact visible finishing line (no undercuts(

79. Complete cast crowns used to restore the molar teeth. The canines and premolars,
which are more visible because of their more anterior arch position, have been restored
with metal-ceramic crowns.