Surveyed Crowns

Question 1

when does one choose to fabricate a surveyed crown?
(3)

Answer 1

-to restore a badly broken down clinical crown
-to reestablish a proper occlusal plane
(ex. supraerupted teeth)
-to create proper rests, particularly with anterior teeth, and adequate retentive undercuts for direct retainers (I-bar, C clasp) and guide plants when inadequate contours exist

Question 2

surveyed crowns and combined fixed RPD cases
varies from

Answer 2

extensive rehabs to when the fixed is confined to abutments associated with the RPD

Question 3

survey crown
is constructed to provide
 is prepared to accept the

Answer 3

appropriate
contours for the prescribed RPD abutment

RPD component

Question 4

skipped
These restorations must be carefully planned and
constructed and must include the appropriate undercuts,
guiding planes, and rest seats:
(5)

Answer 4

1. Accurate diagnostic casts must be made and carefully
   analyzed.
2. Definitive RPD design must be drawn.
3. Mouth preparations must be carefully planned and
   executed.
4. The survey crown preparation
5. Laboratory process

Question 5

3. Mouth preparations must be carefully planned and
   executed.
   It is essential that re-contouring procedures be completed

Answer 5

before crown (fixed restoration) procedures are begun
This includes the preparation of guiding planes and rest
seats.

Question 6

4. The survey crown preparation
   Determine the

Answer 6

retainer design for the crown (all metal,
metal-ceramic, etc.)

Question 7

4. The survey crown preparation
    General considerations:
   (3)

Answer 7

 The occlusal or cingulum rests are constructed in metal
 Areas that engage retentive clasps can be in metal or porcelain
 Guide planes in metal

Question 8

Prepare the tooth for the crown design selected:
(4)

Answer 8

Prepare occlusal or cingulum rest
Consider guiding planes
 Make full arch impression of the prepared
tooth
 An accurate, properly trimmed cast is essential

Question 9

Lab work authorization
(5)

Answer 9

 Must indicate the RPD retainer selected (RPC, RPI,
etc) including height of contour details
 Indicate the desired location and amount (0.1”, 0.2”,
0.3”) undercut for retentive arm
 Indicate rest details (occlusal, cingulum, etc.)
 Indicate material for rest (metal)
 Indicate other metal ceramic requirements (shade,
occlusion, etc)

Question 10

5. Laboratory process
   The wax patterns for the surveyed crowns should
   be appropriately contoured:

Answer 10

Guiding planes should be parallel to the guiding planes on
the remaining teeth. This technique results in improved
parallelism between the guiding planes and provides an
improved restorative result.

Question 11

Guiding planes are created and refined using a

Answer 11

wax knife in the vertical arm of a dental
surveyor.

Question 12

The height of contour is marked using

Answer 12

an analyzing rod in the
vertical arm of a dental surveying

Question 13

Adjustments are made with a

Answer 13

carving instrument

Question 14

The position of the — is verified.

Answer 14

undercut

Question 15

A — instrument is used to finalize rest
seat contours.

Answer 15

discoid

Question 16

Dental ceramics are
strong in —,
but weak in —.

Answer 16

compression
tension

Question 17

If rest is permitted to
bind against the walls of
a rest seat, wedging
forces will result.
The accompanying
tensile forces may
result in

Answer 17

failure of a
ceramic restoration.

Question 18

After casting:
(3)

Answer 18

Crown contours are examined using dental surveyor.
A dental surveyor may be used as a milling device. A handpiece
holder is attached to the vertical arm of the surveyor.
A straight handpiece is then secured parallel to the vertical arm
of the surveyor in handpiece holder.

Question 19

Following the addition of ceramic, crown
contours are evaluated using a

Answer 19

dental surveyor

Question 20

Delivery appointment:
 Prior to patient arriving,

Answer 20

pick up crown, survey to
ascertain whether lab has given you the survey line and
amount of undercut you requested!