Laboratory 11

Question 1

The complete ceramic crown is indicated in areas with a high esthetic requirement where a more conservative restoration would be inadequate. Usually such a tooth has ____ and/or ____ caries, defects, or failing restorations that can no longer be effectively restored with composite resin. The tooth should have sufficient coronal structure to support the restoration particularly in the incisal area, where it is very important not to exceed a maximum porcelain thickness of ____mm. Otherwise, failure of the brittle material may occur.

Answer 1

proximal
facial
2

Question 2

Incisal guiding grooves: Using the modified flat-end tapered diamond, place three depth grooves in the incisal edge. Initially keep them approximately ____ mm-____mm deep to allow for additional finishing. (Figure 11-1)

Answer 2

1. 3

1. 8

Question 3

Incisal reduction: Once completed, remove the remaining islands of tooth structure on the incisal portions. The completed reduction of the incisal edge should provide ____mm - ____ mm of clearance in all excursive movements of the mandible.

Answer 3

1.5

2

Question 4

Facial guiding grooves: Using the modified flat-end tapered diamond, place
three depth grooves (one in the center of the facial surface and one on each of the approximate locations of the ____ and ____ line angles).

Answer 4

mesiofacial

distofacial

Question 5

Your final shoulder finish line will end 0.5mm supragingival. You may want to place the depth grooves approximately 1mm supragingival to allow some space for smoothing and finishing. These orientation grooves will be in ____ planes following the contours of the facial aspect of #7 and #9. The depth of these cuts will be approximately ____mm on the facial. One plane will be in the ____ parallel to the long axis of the tooth. The other will be in the ____ paralleling the tooth contour.

Answer 5

2
0.8
cervical 1/2
incisal 1/2

Question 6

NOTE: The lingual wall height (finish line to incisal portion of cingulum) needs to be at least ____mm in height for retention.

Answer 6

2

Question 7

B. Second plane reduction
! The second plane on anterior teeth is more subtle than that of the posterior teeth and it is placed on the ____ surface only. The second plane maintains ____ and allows for an ____. The second plane should start in the ____ of the facial surface of the preparation. In this preparation, the second plane is placed on the facial in the ____ during the facial reduction.

Answer 7

facial
uniform reduction
esthetic result
middle
incisal 1/2

Question 8

2. To prevent stress concentrations in the ceramic, all ____ and ____ should be ____ (Figures 11-6 and 11-7). Smooth all axial walls and margins with the fine 8847KR-016 diamond. You can also use a finishing bur or white stone on slow speed. Lightly round all sharp angles at this time. A hatchet can be used to smooth the shoulder.

Answer 8

internal line
point angles
rounded