This document discusses the dental surveyor, which is used to determine the parallelism of tooth surfaces on dental casts. It describes the parts of the surveyor including the surveying table, arm, and various surveying tools. The document outlines several purposes of surveying casts such as determining the ideal placement path and identifying guiding planes. It also discusses important terms like height of contour and undercuts. Factors that determine the path of insertion and removal like guiding planes, retention, interference, and esthetics are examined.

1. 1
DENTAL SURVEYOR
By
Dr. Nagham
kassab

2. 2
Definition
An instrument
used to
determine the
relative
parallelism of
two or more
surfaces of the
teeth or other
parts of the cast
of a dental arch.

3. Parts of a Surveyor
 Surveying Table

4. Parts of a Surveyor
 Surveying Arm

5. 5
Surveying Tools
3- Undercut Gauge
1- Analyzing Rods
4- Wax Trimmer
2- Carbon Marker

6.  Surveying Tools

7. Carbon Markers

8. 0.01 0.02
0.03

9. 9

10. Wax Trimmer

11. Purposes of Surveying the
Diagnostic Cast
1. To determine the most desirable path of
placement that will eliminate or minimize
interference to placement and removal
2. To identify proximal tooth surfaces that are, or
need to be, made parallel so that they act as
guiding planes during placement and removal.
3. To locate and measure areas of the teeth that
may be used for retention.

12. 4. To determine whether tooth and bony
areas of interference will need to be
eliminated surgically or by selecting a
different path of placement.
5. To determine the most suitable path of
placemen that will permit locating
retainers and artificial teeth to the best
esthetic advantage.
6. To permit an accurate charting of the
mouth preparation to be made

13. 7. To delineate the height of contour on
abutment teeth and to locate areas of
undesirable tooth undercut that are to
be avoided, eliminated, or blocked out.
8. To record the cast position in relation
to the selected path of placement for
future reference.

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Some Important
Terms

15. Height of Contour (HOC)
Survey line :a line encircling a tooth,
designating its greatest circumference at
a selected position determined by a dental
surveyor.

16. 16

17. Any areas occlusal to survey line used
for placement of non retentive,
stabilizing, or reciprocating elements
Any areas cervical to survey
line used for placement of
retentive clasp components

18. 18

19. 19
Types of undercuts
Tooth Undercuts *
Soft Tissues or bony
Undercuts(on lingual
side of ridge) #

20. Angle of Cervical Convergence
An angle viewed between a vertical rod
contacting an abutment tooth and the
axial surface of the abutment cervical
to the height of contour.

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22. Advantages of a Single Path of Insertion
 1- Equalizes retention

23.  4- Allows removal without
encountering interferences
 6- provide frictional rttention

24. Factors Determining Path of
Insertion & Removal




Guiding planes
Retentive areas
Interference
Esthetics

25. Guiding Planes


Two or more vertically parallel flat surfaces of
abutment teeth shaped to direct a prosthesis during
placement and removal where rigid components
contact abutments
*

26. Guiding Planes Functions



1- ensure passage of the rigid parts of prosthesis
past existing areas of interference. #
2- to control & limit directions of movement of RPD as
it is being inserted, removed or while in function.
3- to ensure predictable clasp assembly function,
including retention and stabilization *

27. Effectiveness of Guiding Planes



Most effective when:
A- Parallel to each other
B- More than one common axial surface
 C- Directly opposing each other


D- Prepared on several teeth
E- Cover a large surface are(proximal &
lingual)

28. Preperation Of Guiding Planes
 Long
Cylindrical
Carbide or
Diamond)

29. Retentive Areas
 Retentive arm should have a
different path of escapement than
guiding plane (path of removal), so
retentive arm must be forced to flex
over a convex surface during
placement and removal (retention) *
For a clasp to be retentive, its path of
escapement must be other than parallel to
the path of removal of the denture itself.

30. 

Retentive undercuts equalized
Ideally, retentive arms should oppose
each other on opposite sides of the
arch with fairly even retention *

31. (Interference) *
Prosthesis must be designed so that
it may be placed and removed
without encountering tooth or soft
tissue interference

32. Interference
If the interference is bilateral, surgery or
recontouring of lingual tooth surfaces, or
both, may be unavoidable.
If it is only unilateral, a change in the lateral
tilt may prevent an area of tooth or tissue
interference.

33. Interference



Bony undercuts
1- to remove them surgically;
2- to change the path of placement at the
expense of modifying or restoring teeth to
achieve guiding planes and retention;
3- to design denture bases to prevent such
undercut areas.
Generally, interference that cannot
be eliminated for one reason or
another will take precedence over
the factors of retention and
guiding planes.

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35. (Esthetics)
A path of insertion should be
selected to provide the most
esthetic placement of artificial teeth
and the least amount of visible
metal on the abutment teeth.
Ensure that the retentive undercut
and the height of contour are not
placed too far occlusally, so that
the retentive clasp and that anterior
proximal plates are close to the
gingival contours making these
components as inconspicuous as
possible.

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38. 38
Parts
of a Dental Surveyor
B-Vertical Upright Column
C-Cross Arm with Spindle
Housing
D-The Vertical Spindle With
Tool Holder
E- Screw To Lock The Spindle
F- Tool adaptor Holder
G- Surveying tool holder
J- Model Clamp
K- Model table lock nut
L- Model rotating ball & socket
M- Ball rotating ring
N- Tool Rack
O- Storage Compartment
P- Model lock nut

39. Thank you