Got gkchmckuckuc

1. SURVEYING IN RPD

2. TERMINOLOGIES :
SURVEY-”The procedure of locating or delineating the contour and
position of the abutment teeth and associated structures before
designing a partial denture.”-GPT 9
SURVEYING-”An analysis and comparison of the prominence of
intraoral contours associated with the fabrication of a prosthesis”-GPT
9
SURVEYOR-”An instrument used in the construction of a removable
partial denture to locate and delineate the contours and relative
positions of abutment teeth and associated structures.”-GPT 9

3. SURVEY LINE
• A line drawn on a tooth or teeth of a cast by means of a
surveyor for the purpose of determining the positions of the
various parts of a retainer-GPT 9
GUIDING
PLANE
• Two or more vertically parallel surfaces of abutment teeth so
oriented as to direct the path of placement/removal of a
removable partial denture
PATH OF
INSERTION
• The direction in which a prosthesis is placed upon and
removed from the abutment teeth-GPT 9
HEIGHT OF
CONTOUR
A line encircling a tooth designating its greatest
circumference at a selected position

4. TYPES OF SURVEYORS
1) Ney’s surveyor
2) Wills surveyor
3) Electronic surveyor
4) Paratherm surveyor
5) Stressograph
6) Broken arm cast surveyor
7) Optical surveyor
8) Laser surveyor
9) Parallelometer
10)Other surveyors are: austenal microanalyzer, krupp model k3,
arthogyr model 1670, galloni isoparallelometer model 1020,
bachmann parallelometer

5. PURPOSES OF SURVEYING
•Determine the most advantageous path of insertion.
•Locate proximal tooth surface- guiding surfaces
•Locate and measure undercuts
•Identify hard and soft tissue interferances
•Determine a path of insertion consistent with esthetic requirements
•Delineate the height of contour of the abutment teeth and identify
areas of undercut
•Planning restorative procedures
•Record the most ideal cast position for future reference
•Plan for RPD design and the required mouth preparation

6. PARTS OF A SURVEYOR :
PLATFORM
CAST HOLDER/
SURVEYING TABLE
VERTICAL ARM
HORIZONTAL
ARM
MANDREL
SURVEYING ARM

7. SURVEYING TOOLS :
Analysing Rod
Carbon Marker
Undercut Gauge
Wax Trimmer

8. ANALYSING ROD :
Used for preliminary survey of the cast
Assessment of degree of undercuts on hard and soft tissues
Assessment of angulation of teeth
In distal extension cases, allow judgement of whether the distal abutment
undercuts are sufficient to indicate that a tilt may be beneficial.

9. CARBON MARKER
•Basically allows visualization of the analysing rod’s work.
•Used for drawing survey lines around all the teeth involved in clasp
design or that have proximal undercuts to be eliminated.
•To mark the extent of bony/soft tissue undercuts for prosthetic
mouth preparation if required.

10. UNDERCUT GAUGES :
•Used to measure the location and horizontal depth of undercuts on
•the analysed and marked teeth in three dimensions
•Stewart – o.o1”,0.015”,0.02”
•McCracken-0.01”,0.02”,0.03”
•Same shank,only the size of the tip/bead varies (except Neys)

11. WAX TRIMMERS :
Used to trim off excessive wax while surveying the wax
patterns
To prevent over contoured block out of unfavourable
undercuts.

12. COMPARISON OF NEY’S & JELENKO
1. Horizontal arm is fixed
2. Vertical arm is retained
by friction
3. Shaft remains in any
vertical position until again
it is moved
4. Cast table is moved
around surveyor platform
1.Horizontal arm is movable
2. Vertical arm is spring
mounted
3. Vertical arm when released
returns to its original position,
it should be held against
spring tension
4. Cast table is fixed to the
surveyor platform
SURVEYOR

13. SURVEY LINES :
Louis
Blatterfein’s
division of
abutment
teeth into
near zone
NZ & far
zone FZ
High
Medium
Low
Diagonal

14. Any rigid,nonflexible
part of the prosthesis
must be designed to
lie above the survey
line,and only flexible
parts may be designed
to go below it.
It helps to locate areas
of undesirable tooth
undercuts that must be
avoided or eliminated.
SIGNIFICANCE OF SURVEY LINES

15. HIGH SURVEY LINE: From occlusal 1/3rd
in NZ to occlusal 1/3rd in FZ.
MEDIUM SURVEY LINE: from occlusal
1/3rd in NZ to middle 1/3rd in FZ.
LOW SURVEY LINE: From cervical 1/3rd in
NZ to cervical 1/3rd in FZ.
DIAGONAL SURVEY LINE: From occlusal
1/3rd in NZ to gingival 1/3rd in FZ.

16. NEY’S CLASSIFICATION
Class I:
Survey line runs
diagonally across
the tooth surface
The type of clasp
indicated is occlusally
approaching cast
clasp with terminal
third engaging the
undercut.
.
Class II:
Survey line also
runs diagonally
across the tooth
surface but as a
mirror image of
Class I line. Here a
gingivally
approaching clasp
arm is suggested.
Class III:
Survey line is
parallel to the
occlusal surface
and lies just below
it

17. HEIGHT OF CONTOUR:
First termed by KENNEDY
Represents the greatest bulge of diameter of a crown when viewed
from a specific angle or changes as the vertical position of the tooth
changes
Tipping or tilting the cast will cause the height of contour to move
accordingly

18. DE VAN 1935
SUPRA BULGE :
Surface of the
tooth that is
occlusal to the
height of contour
INFRA BULGE :
Surface gingival to
the height of contour

19. PATH OF INSERTION :
RETETIVE
UNDERCUTS
INTERFERENCES &
GUIDING PLANES
ESTHETICS
FACTORS
AFFECTING

20. RETENTIVE UNDERCUTS :
When surveying diagnostic casts for rpd,retentive undercuts must be present
on abutment teeth when the cast displays a horizontal tilt
.
This is necessary because dislodging forces are always directed perpendicular
to the occlusal plane.

21. INTERFERENCES
In the maxillary arch –
•palatal torus
•exostoses and undercuts on the buccal surfaces of the maxillary arch
•facial tipping of posterior teeth
•anterior soft tissue undercuts

22. In the mandibular arch –
•mandibular tori
•lingual tipping of the posterior teeth
•bony prominences often encountered at the facial surfacesof
mandibular canines and premolars.
•Soft tissue undercuts


23. ESTHETICS:
•To obtain optimum esthetics,the metal,usually in the form of clasp arm, must be
concealed without compromising necessary support and stability of the prostheses.
•The artificial teeth must be placed in the most natural position possible.
•Avoiding unnecessary display of the metal,the tilt of the survey table should be
such that the survey line on the teeth that are visible be as close to the gingival
margin
•The ideal position of the clasp for the retentive purpose is gingival. third of the
tooth
.

24. GUIDING PLANES :
Guiding planes are formed from the proximal tooth surfaces of the teeth and are
contacted by the minor connectors or other rigid components of the partial
denture.
These planes guide the prostheses for removal and placement.
The guiding planes are in intimate contact with the minor connectors,help to
stabilize against the lateral forces.

25. NUMBER OF PATH OF
INSERTION:

26. STEP BY STEP PROCEDURES IN SURVEYING A
DIAGNOSTIC CAST
Orientation of cast
Cast tilting
Visual analysis using analysing rod
Marking of survey lines /soft tissue undercuts using carbon markers
Undercut gauges used to measure amount of available retention
Interferences
Wax Trimmers
Tripoding of casts

27. ORIENTATION OF CAST
Casts oriented such that the anterior part is always toward thevertical member of
surveyor and away from the operator
Position for description is fixed for either cast.
Can be attached to the holding table via:
Soft plasticine or wax
Locking screws engaging the sides of model
o Magnetised iron cast into base of model

28. CAST TILTING
Tilting is changing the position of the cast, which thus changes the long axis of each
tooth relative to the horizontal plane.
Alters the contour, positions, location & depth of undercut relative to the new plane.
Allows
The most advantageous path of insertion
Increase in desirable and decrease in undesirable undercuts
Distribution of available undercuts to produce more uniform retention throughout the
available teeth & tissues
Establishes parallelism & improvises upon esthetics
:
.

29. VISUAL ANALYSIS USING ANALYSING ROD
Primarily responsible for “eyeballing” of the cast.
Once orientation & tilt is established, allows for a general tangential
analysis of undercuts, tooth angulations, etc.
Also aids the establishment of relative parallelism of various planar surfaces

30. MARKING OF SURVEY LINES /SOFT TISSUE
UNDERCUTS USING CARBON MARKERS
Analysis by the analysing rod is visualised via the carbon marker.
5H pencil graphites secured with metal reinforcement sheath

31. UNDERCUT GAUGES USED TO MEASURE
AMOUNT OF AVAILABLE RETENTION
These gauges are used to identify the specific amount
and location of desired retentive undercut on the surface
of the abutment teeth
The undercut is best viewed against light passing through a
triangle bounded by surfaces of abutment tooth, surveyor blade
,apex being the point of contact at the height of convexity and base
of triangle being the gingival tissues.
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32. Undercut utilisation
o 0.01 → cast retainers
o 0.02 → wrought wire retention
o 0.03 → rarely used
If no retentive undercuts are present, they must be created by:
o Gold Crowns
retentive restorations.
creating an undercut by tooth modification

33. WAX TRIMMERS
Once unfavorable undercuts are blocked, to prevent overcontouring, wax
trimmers are used.
In case of distal extension cases, to create a gap/self cleansing area under the
saddle, a 25 trimmer is used in conjunction.
Wax patterns for casting can also be carved accordingly
.

34. PRESERVING THE TILT THROUGH
TRIPODING :
Once tilt has been selected for given rpd design, this tilt should be preserved,so
that it can be re-established accurately to the surveying table.
This procedure is termed as “ TRIPODING”.This helps in returning the cast to
the surveyor for future reference.


36. SURVEYING THE MASTER CAST :
Surveyed as a new cast
Prepared proximal guiding plane surfaces will indicate the correct AP tilt.
Any remaining interferences after mouth preparation must be eliminated with
block out
Survey lines marked

37. CONTOURING OF WAX PATTERNS
Surveyor blade – used as wax carver
Proposed path of placement maintained through out preparation of cast
restorations for abutment teeth.
Surfaces of restorations that provide reciprocation for clasp arms have
to be contoured to permit their location well below occlusal surfaces
and on non retentive areas

38. BLOCK OUT
After the establishment of path of insertion and the location ofundercut
areas on the master cast, the areas that shall be crossed by the rigid parts
of the denture must be blocked out.
Roach carver or No.7 spatula used to adapt the blocking wax.
Four types:
Parallel Blockout
Shaped Blockout/Ledge Blockout
Arbitrary Blockout
Relief

39. https://youtu.be/oozJhYVZNgU