Dr. Waseem Mushtaha Removable prosthodontic Al azhar university Gaza Lama El Banna

1. SURVEYING
Dr. Waseem Bahjat Mushtaha
Specialized in prosthodontics

2. Definitions:
Dental surveyor:
A paralleling instrument used in the fabrication of a
removable partial denture.
Surveying:
The procedure of analyzing and delineating the
contours of the abutment teeth and associated
structures before designing a removable partial
denture.
Path of insertion (placement(:
The specific direction in which a prosthesis is placed
upon the abutment teeth.

3. Components of dental surveyor:
1-Base.
2-Vertical arm.
3-Horizontal arm.
4-Spindle with tool holder. The surveying arm is
capable of movement in vertical direction.
5-surveyor table, to which the cast is attached. The
cast is locked in place on the table by a clamp. The
table is mounted on a ball and socket joint that
permit the cast to be tilted in various planes

5. 6-Surveyor tools:
a-Analyzing rod
is a straight metal shaft used to analyze the cast to evaluate
the presence or absence of undercut.
b-carbon marker and reinforcing sheath,
used to draw the survey line of the teeth and to delineate an
undercut area of the soft tissue of the ridge.
c-Undercut gauges,
are used to identify the amount of the retentive undercut. It is
available in three sizes; 0.01, 0.02 and 0.03 of an inch.
d-wax trimmer,
used to eliminate or block out areas of undesirable undercut
with wax.

6. Analyzing rod

7. carbon marker

8. Undercut gauges

9. wax trimmer

10. Uses of dental surveyor
1-Determination of the most acceptable path of
insertion and removal. Whenever possible, the
path of insertion should be selected while the cast
is placed horizontally with its occlusal plane
parallel to the base of the cast.
2-Identifying the proximal tooth surfaces that may
be used as guiding planes. The guiding planes are
the proximal tooth surfaces that are prepared to be
parallel to each other and to the path of insertion.
These planes contribute to the stability of the
partial denture

11. 3-Locating and measuring undercut areas of the
teeth that may be used for retention. An undercut
area is that portion of a tooth lies gingival to the
survey line (height of contour(.
4-Determination of the most suitable path of
insertion for retention and esthetic.
5-Detetmination of tooth and bony areas
interference that would be eliminated surgically or
by selecting a different path of insertion.
6-Aid in determining mouth preparation and
restorative procedures (e.g. the preparation of
proximal tooth surfaces to provide guiding planes
and the reduction of excessive tooth contour to
eliminate interference(.

14. 7-Drawing the survey line (height of contour)
on the abutment tooth. The survey line is a
line encircling a tooth at its greatest
circumference at a selected cast position
8-Location of undesirable undercuts which
should be blocked out before duplication.
9-Recording the cast position in relation to
the selected path of placement for future
reference. This may be done by locating
three parallel lines or three dots in the same
horizontal plane on the cast (tripodization(.

18. Factors that determine path of placement and
removal:
The factors that determine the path of
placement and removal are guiding planes,
retentive areas, interference, and esthetics.
Tilting the cast on a surveyor during the
determination of the path of placement and
removal will help in:
1-Aligning the proximal guiding planes to be
more favorable to the path of insertion

19. 2-Redistribution of the retentive undercuts in
both sides of the arch
3-Elimination of soft tissue interference.
4-Selecting the most suitable path of
placement for esthetic, by development of
symmetrical embrasure spaces and placing
the clasp terminals in areas with less metal
display.

20. Procedures for surveying the study cast:
1-Determining tire path of insertion:
a-The cast is attached to the surveyor table with the occlusal plane parallel to the
base of the surveyor.
b- The analyzing rod is placed in the tool holder and the surveying table is moved
until the analyzing rod contact the occlusal third of the proximal surfaces of
the abutment teeth.
c-The proximal walls usually determine the path of insertion and may require
some tooth preparation to be parallel.
2-Determining the undercut areas:
a-The analyzing rod is used to locate the undercut areas. The amount of undercut
is measured by undercut gauges.
b- The undercuts can be redistributed on various abutments by tilting the cast.
c-The location of the undercuts must be suitable for the function and esthetics of
the clasp. The abutment teeth may have to be: modified or restored, to obtain
proper contour.
d- Tissue undercuts that may act as interference for the RPD should be determined
on the diagnostic cast.
e- The adjustable table is then locked in the selected position.

21. 3-Drawing the survey line:
The analyzing rod is replaced with a carbon
marker. The height of contour is marked on
the abutment teeth and other tissue
prominence
4-Tripodizing the cast:
The cast position on the surveyor table is
recorded for future reference to the selected
path of insertion by marking it with three
widely separated dots or lines.