This document provides an overview of surveying and surveying tools used in the process of designing removable partial dentures (RPDs). It discusses the history and development of surveying, types of surveyors, principles of surveying including survey lines and path of insertion. The document outlines the step-by-step survey process including orienting the cast, tilting, marking survey lines, measuring undercuts, identifying interferences, and tripoding the cast for future reference. Various surveying tools such as the analyzing rod, carbon marker, undercut gauges, and wax trimmers are also described.

1. SURVEYORS & SURVEYING
IN RPD
PRESENTED BY :
ANNESHA K. KONWAR
MDS II nd YEAR

2. CONTENTS
 INTRODUCTION
 TERMINOLOGY
 HISTORY & DEVELOPMENT
 TYPES & USES OF SURVEYOR
 PRINCIPLES IN SURVEYING
 SIGNIFICANCE OF SURVEY LINES
 PARTS OF DENTAL SURVEYOR
 SURVEY PROCESS
 RECENT ADVANCES
 CROSS REFERENCES
 CONCLUSION
 REFERENCES

3. INTRODUCTION
 A partial denture will not succeed unless it is designed and
constructed in harmony with all the physiologic and mechanical
problems present in the patient’s mouth.
 Surveying and designing are important steps towards
achieving a successful restoration.
 A well-executed design serves as a blueprint for fabrication of
the removable partial dentures.
 Lack of plan,haphazard preparation and lack of abutment
preparation are a few factors of partial denture failure.

4. 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 8
SURVEYING-”An
analysis and
comparison of the
prominence of intraoral
contours associated
with the fabrication of
a prosthesis”-GPT
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 8

5. 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 8
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 8
HEIGHT OF
CONTOUR
A line encircling a tooth designating its greatest
circumference at a selected position

6. HISTORY AND
DEVELOPMENT
 During the first part of the twentieth century, RPD were
designed and constructed using arbitrary techniques
“eye balling”.
 The turning point in the change of partial denture construction
from guesswork based on clinical experience to scientifically
based procedure was the appearance of the dental surveyor in 1918.
 Dr. A.J. Fortunati
 In 1923 the J.M. Ney Corporation produced the first commercially
available, the Ney instrument.

7. HISTORICAL PERSPECTIVE : 1860 : Dr. J.
Richardson.
1890 : Dr
W.M.
Randall’s
technique.
1905 : Dr
Herman E.S
Chayes’
Parallelomete
r
1920 :
Robinson
surveyor by
Philadephia
Dental Clinic
club.
1923 : The
original ney
surveyor by
Weinstein &

8. 1937 : Ney surveyor
– the current model.
1929 : The original
Wills surveyor by
noble G Wills.
1937 : Wills
Surveyor-the
current model
1942 : King’s
College Surveyor.
1944 : The Roach
Surveyor.

9. >The Electrome >The Retentoscope >The
Stressograph
>Broken-arm > Pendulum Surveyor >Optical
Surveyor

11. WILLIAMS SURVEYOR
 It has a Gimbal stage table -adjustable to
any desired tilt. Degree of inclination can
be recorded for repositioning of cast at any
time.
 Superstructure of this surveyor consists of
jointed arm and spring-supported survey
rod, all components of which can be locked
in fixed position if desired.

12. THE HIGHRISER RPD SURVEYOR
 A pendulum arm Block out/Survey Instrument.
 Allows fluid movement.
 The arm can freely swing back and forth,
rotate, or move up or down.
 Arm can be locked to hold it at a set vertical height.
 Spring tension is easily adjusted
 Heating element attachment is designed for easy use and various size
tips are available.

13. THE SKYSCRAPER SURVEYOR
 A dual pendulum Electronic Block out / Survey
instrument.
 The dual arm system has several advantages :
-The heating element does not have to be removed when
surveying
-By simply rotating the column the new tool is ready for
use.

14. THE THERMA-SCULPT SURVEYOR
ATTACHMENT
 The Therma-sculpt is an electronically heated arbor
that can be easily attached to Ney-Jelenko type
surveyor.
 The design concept allows the technician to
perform varied wax sculpting tasks : from block
out of RPD, to attachment and implant procedures.

15. PURPOSES OF SURVEYING
 Determine the most advantageous path of insertion.
 Locate proximal tooth surfaces - guiding surfaces.
 Locate and measure undercuts.
 Identify hard or soft tissue interferences.
 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 the RPD design and the required mouth preparation.

16. PARTS OF A SURVEYOR :
PLATFORM
CAST HOLDER/
SURVEYING TABLE
VERTICAL ARM
HORIZONTAL
ARMMANDRE
L
SURVEYING ARM

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

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

19. CARBON MARKER
 Basically allows visualization of the analysing rod’s work.
 Used for drawing survey lines around all 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.
 Light pressure without erosion.

20. UNDERCUT GAUGES :
 Used to measure the location and horizontal depth of undercuts on
the analysed and marked teeth in three dimensions.
 Stewert – 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)

21. WAX TRIMMERS :
 Used to trim off excessive wax while surveying the wax
patterns.
 To prevent overcontoured blockout of unfavourable undercuts.
 To demarcate the exact planned clasp arm location to be
duplicated.
 To create a gap/self cleansing area using a 25 trimmer.

22. COMPARISON OF NEY’S & JELENKO
SURVEYOR
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

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

24. SIGNIFICANCES OF SURVEY
LINES :
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.

25. 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

26. NEY’S CLASSIFICATION
26
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

27. 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.

28. 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

29. PATH OF INSERTION :
RETETIVE
UNDERCU
TS
INTERFERENCES &
GUIDING PLANES
ESTHETICS
FACTORS
AFFECTING

30. 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.

31. IDENTIFYING THE MOST FAVOURABLE TILT :
Tilting is changing the position of the cast,which thus changes the
long axis
of each tooth on the cast relative to the horizontal plane.
Change in the tilt then changes the position of survey line and
location and
extent of the undercut.

32. The basic position or tilt of the cast on surveyor should be the
horizontal tilt.
In the horizontal tilt,occlusal surfaces of the teeth are at or near parallel
to the horizontal plane.

33. The anterior tilt increases the mesial undercut on the teeth.
In the posterior tilt,the occlusal plane is lower in the posterior region.
The posterior tilt will increase the distal undercut and decrease the
mesial undercut.

34. 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

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

36. BONY UNDERCUTS

37. 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.

38. 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.

39. NUMBER OF PATH OF
INSERTION:

40. 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

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

42. 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.

43. Dislodging forces primarily to occlusal plane.
 Hence, HORIZONTAL or 0.
TILT most common(Not>10˚).
 Other tilts:
o Anterior
o Posterior
o Lateral

44. 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.

45. 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

46. 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 tooth.
 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.
46

47.  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
o Retentive Restorations
o Creating an undercut by tooth modification

48. 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.

49. 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.

51. Methods for tripoding a cast :
METHOD 1 :
By placing widely spaced dots on the tissue surface of the cast using
the tip of the carbon marker, with the vertical arm of the surveyor in a
locked position.

52.  METHOD 2
 Scour 2 sides and the dorsal
aspect of the base of the cast with
a sharp instrument/ marking
pencil held against the surveyor
blade.
 Marks don’t interfere with the
design
 Easy duplication
 May get smudged upon
handling

53.  METHOD 3
 A hole about 10 mm in diameter and
10 mm deep is prepared in the
lingual land area of the mandibular
cast with a large acrylic finishing bur.
 The pin is locked in the vertical
spindle and lowered to the bottom of
the hole.
 The vertical spindle with the pin is
then locked in this position and the
hole is filled with dental plaster.
 Once the plaster is set, vertical
spindle is released from cemented
pin.

54. METHOD 4
 An instrument reproduces the tilt
of a cast on a surveyor using
protractor
 Flat metal strip 5mm wide and
3cm long, one end of which bend
upward at 90˚
 Metal rod is attached to the end of
the flat part of the strip which
serves to fit the instrument to the
surveyor
J Prosthet Dent 1965;34(3)465-471

55.  A hole is tapped and threaded in
the middle of the bent part of
metal strip through which a
protractor is screwed
 The protractor can rotate around
the metal rod, acting as a pointer.
 After determining the path of
insertion, the protractor
instrument is mounted on the
surveyor in place of analyzing rod
 3 divergent points are marked,
with readings recorded at each tilt

56. METHOD 5
 Make a hole in the tongue space
on mandibular cast 4-6mm in
diameter
 Hole should create undercut but
should not perforate the base of
the cast
 Following normal surveying
procedures, a parallel shanked
straight handpiece bur is
suspended.
J Prosthet Dent 1981;41(3):352-354

57. • With the bur in place, fill the
hole with autopolymerizing
acrylic resin
 For reorientation, reposition the
bur in autopolymerizing resin
for a parallel tripod record.

58. METHOD 6
 Wax deposited on side of
cast at 3 widely separated
points
 Analyzing rod used to create
imprints of wax
 This can be transferred by
duplication

59. METHOD 7
 Make a universal tray on a
cast after adapting 2 thickness
of baseplate wax over the
teeth.
 Make a platform with a
cylinder over the tray and
insert analyzing rod into
cylinder.
 Move the tray to and fro
vertically during setting of
the material to make a smooth
vertical perforation in
cylinder.

60.  Tray loaded with elastic
impression material, the cylinder
is attached to the rod and locked
 After establishing tilt, an
impression is made
 Reorientation can later be done
by placing the impression on
cast and the tilt at which the
stylus can enter the cylinder
locks the prior position

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

62. SURVEYING IN CONFINED AREAS
J Prosthet Dent 1991;61(5):378-380

63.  Orthodontic wire can be used as a
horizontal "feeler gauge“ in combination
with the vertical analyzing wire to
estimate the adequacy of the retentive
undercut.
 Dimensions of the wire allow for finer
measurements.

64. CONTOURING OF WAX PATTERNS
 Surveyor blade – used as wax carver
 Proposed path of placement maintained throughout 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

65. BLOCK OUT
 After the establishment of path of insertion and the location of
undercut 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:
o Parallel Blockout
o Shaped Blockout/Ledge Blockout
o Arbitrary Blockout
o Relief

66.  Parallel Blockout:
 Performed:
o On interproximal surfaces to be used as guiding
planes(0/2/6˚ taper)
o Beneath all minor connectors
o On tissue undercuts to be crossed by rigid connectors
o Beneath bar clasp arms to gingival crevices
 Materials Used:
o Hard baseplate wax
o Hard inlay wax
o Oil based modelling clay
 Thickness-Only undercut remaining gingival to contact of
surveyor
blade with tooth surface

67.  Shaped/Ledge Blockout:
 Performed:
o On buccal & lingual surfaces to locate plastic or wax
patterns for clasp arms
 Material:
o Hard Baseplate Wax
 Thickness: Ledges for location of reciprocal clasp arms to follow
height or convexity so that they may be placed as cervical as
possible without becoming retentive

68.  Arbitrary Blockout:
 Performed:
o On all gingival crevices
o On gross tissue undercuts below areas involved in
framework design
o On tissue undercuts distal to cast framework
o Labial & buccal tooth undercuts not involved in denture
design
 Material:
o Oil Based Modelling Clay
o Hard Baseplate Wax
 Thickness:Enough to just eliminate gingival
crevice, levelled arbitrarily with a wax spatula

69.  Relief
 Provided:
o Beneath lingual bar connectors or the bar portion of
linguoplates
o On areas in which the major connector will contact thin
tissue
o Beneath framework extensions onto ridge areas for
attachment of resin bases
 Material:
o Adhesive wax
o Hard Baseplate Wax
 Thickness:
o 32 gauge wax(universally)
o 20 gauge wax for resin base attachment relief

70. PLACEMENT OF INTERNAL REST SEATS
 Large box shaped metallic extensions that function as intracoronal
extensions.
 Carved in wax patterns and refined further with hand piece after
casting.

71. MACHINING OF CAST
RESTORATIONS :
 Rotary instruments can be attached to the surveyor via a handpiece
holder for trimming/machining of restorations.
 Surveying arm can then be rotated around the restoration to trim
excess crown material.

72. SURVEYING CERAMIC VENEER CROWNS
 Ceramic veneer crowns is used to restore abutment on which an extra-
coronal rest is placed
 Surveyor is used to contour wax pattern except labial or buccal
surfaces for
esthetic reasons
 Repositioning on surveyor, reshaping with stones may be required
before final Glazing of veneer crowns

73. PLACEMENT OF INTRA CORONAL RETAINERS
Surveyor is used to
 To select a path of placement in relation to the long axes of abutment
teeth
 To cut on diagnostic cast to estimate proximity to pulp
 To carve wax patterns, to place internal attachment in wax patterns or
to cut recesses in casting
 To place keyway portion of attachment in casting

74. PLACEMENT OF INTERNAL REST SEATS
 Surveyor used as a drill press
 Internal rest seats carved in wax pattern, defined in casting or
entirely cut in cast restoration
 It provides positive occlusal support and horizontal
stabilization
 Internal rests may be of Retentive, Non-retentive or Semi-
retentive
forms

75. WHAT’S NEW?? - THREE DIMENSIONAL
COMPUTER AIDED SURVEYING
J Prosthet Dent 2004;92(3):408-412

76.  Programs were written for this
technique using mathematic software
(MatLab:The Math Works, Inc, Natick,
Mass)
 The program identified all downward
facing surface triangles on scan as –ve
& upward facing as +ve, the junction
being the survey line.

77.  Tilting the cast allows for
accurate re-record of the new
survey line.
 20˚ tilt
 This can then be reproduced onto
the digitally scanned tooth
structure.

80. CONCLUSION
 Preservation of abutment teeth and supporting structures of the oral
cavity depends on accurate and knowledgeable survey and design.
To plan, survey, and design a removable partial denture which will
provide proper retention, support, stabilization, and esthetics, is
essential for the success of the removable partial denture.

81. REFERENCES
 Stewart’s clinical REMOVABLE PARTIAL PROSTHODONTICS
– 4th Edition and 2nd edition
 McCracken’s Removable partial prosthodontics
– 11th Edition
 An Atlas Of Removable Partial Denture Design – Stratton
 Dental Laboratory procedures for Removable Partial Denture
- Rudd and Morrow