The document provides information on surveying and designing removable partial dentures (RPDs). It discusses the history and definition of surveying, the types and parts of surveyors, and the surveying process. Key steps in surveying include determining the optimal tilt of the dental cast, identifying retentive undercuts, addressing interferences, and establishing guiding planes and the path of insertion. Design considerations include stress distribution philosophies, clasp placement, and color coding for communication with the dental laboratory. The surveyor is used throughout the process to accurately locate anatomical landmarks and mechanical features needed to design an RPD that restores function without damaging remaining oral structures.

1. Survey and Design
Dr.Neha srivastava
Senior lecturer
Rama dental college
Kanpur

2.  INTRODUCTION
Surveyor introduced by Dr.A.J.Fo
rtunati -1918
First commercially available surve
yor-J.M.NEY in 1923
Definition: A paralleling instrument
used in construction of a Dental Pr
osthesis to locate & delineate the c
ontour & relative positions of abut
ment teeth & associated structure
s.

3. Uses of surveyor
 To survey the Diagnostic & Primary cast
 For Tripoding the cast.
 To transfer the Tripoding
 Contouring the crowns
 Placing the internal attachment and rest
 Performing Mouth preparation.
 Surveying the Master Cast.
 Surveying ceramic veneers

4. Types
Wills surveyor ( jelenko )….spring loaded
(revolved horizontal arm)
Ney surveyor…Fixed horizontal arm (surveyi
ng arm is positioned by a locking device) c
o.

5.  Objective & needs of surveying
1.To determine the path of insertion
2.To mark the height of contour
3.To mark the survey line.
4.To mark the undercuts.To prevent
the prosthesis from encroching the
undesirable under cut.
5.To design the RPD so that the
components are approximate
positioned to obtain good results.

6. Parts of surveyor
A. Level platform tha
t is parallel to the
bench top & on ca
st holder is moved
B. A vertical column t
hat supports the s
upra structure. A
horizontal arm tha
t extends at right
angle.

7. C. A Surveying arm t
hat extends vertic
ally from the horiz
ontal arm.
The surveying arm is
capable of movem
ent in the vertical
direction
It has a mandrel at t
he Lower ends

8. Surveying Tools
1.An Analyzing rod: used to determine re
lative parallelism of the surfaces on a d
ental cast.
2.Carbon marker: Used to mark the heig
ht of contour on one or more surfaces
3.Undercut Gauges:
Used to identify the
position of desired
undercuts on the
dental cast

9.  Wax knife:
Used during block
out Procedures
 Surveying Table:
Designed to Hold
a dental cast.

10. Survey process:
 Dental arches may present with complic
ating factors such as soft tissue underc
ut & Bony prominences
 The contours of proposed abutment mu
st be analyzed & co-ordinated with othe
r teeth that will be constructed by the R
.P.D.

11. Surveying process is
composed of several phases
Identifying the most favorable tilt
Anterior Tilt
Posterior Tilt
Left Tilt
Right Tilt
Any combination of tilts may be used but ex
treme tilt should be avoided

12.  Factors to determine the most favorab
le tilt of dental cast
1.The presence of suitable undercut.
2.Elimination of Hard & Soft tissue interf
aces.
3.Creation of desirable esthetics
4.Establishment of appropriate guiding p
lanes.

13. Retentive Undercuts
 Retentive undercuts must be present w
hen the cast displays a horizontal tilt.
 This is essential because
dislodging forces are always
directed perpendicular to
the occlusal plane
 These forces may include the pull produ
ced by Sticky food or force of gravity fo
r maxillary denture

14.  The surveying procedure starts with the
cast firmly attached to the survey table
& the occlusal surface parallel to the pla
tform of the surveyor. In turn ,each abu
tment is examined for retentive undercu
ts by using analyzing rod.
 If retentive undercuts are not they must
be created in the Mouth. This can be do
ne by recontouring enamel surface.
 In case more extensive changes it may
be necessary to place a fixed restoratio
n

15.  Ideally ,proposed abutment should di
splay a 0.010 Inch undercut at the m
ost desirable location
 It can be Mesiobuccal Line angle
Distobuccal Line angle
Mid facial Surface
 If wrought wire clasp is placed 0.015
inches is needed because of greater f
lexibility of wrought wire

16. Interferences
 Like Tooth, Bony prominences, soft tiss
ue undercuts & exostoses
 In some instances ,difficulties may be a
voided by changing the tilt of the cast o
n the surveying table.
 In other instances, surgical intervention
s may be necessary to correct undesira
ble contours.

17. Interferences like palatine tori can be
dealt only by changing the design of
the Major connector.

18. Esthetics
With surveying we
can disguise removable p
artial denture component
s while maintaining the h
ealth
of the associated soft tiss
ues.
The ideal position for a r
etentive clasp is in the gi
ngival third of the clinical
crown

19.  Large undercuts on the proximal surfaces of
anterior teeth produce triangular spaces tha
t not only detract from the esthetic value of
the removable partial denture, but also act
as food traps that can be annoying to the p
atient.
 These spaces should by minimized or elimin
ated by moditying the tilt or recontouring t
he proximal surfaces of the offending teeth.
 The surveyor is a necessity in determining t
he amount of recontouring needed to reduc
e these undesirable undercuts.

20.  Guiding planes:
Guiding planes are parallel surfaces o
f abutment teeth that direct the insertio
n and removal of a partial denture.
They are formed on the proximal or a
xial surfaces of the teeth and are contac
ted by the minor connectors or other rig
id elements of the removable partial de
nture.
 The surveyor is used to locate these Gu
iding Planes.

21.  Guiding planes are always parallel to
the path of insertion and are rarely g
reater than 2 to 4 mm in height.
 As a result, guiding planes help stabil
ize the prosthesis against lateral forc
es.
 They also help protect weakened tee
th from potentially destructive lateral
forces.
 Guiding planes can be prepared on m
ost enamel surfaces

22. Path of insertion:
The tilt of a cast
determines the direction
that the partial denture
will take during placement
and removal.
The resultant pathway
is termed the
path of insertion.
For practical purposes,
the path of insertion and
removal will always be
parallel to the vertical arm
of the surveyor

23. Path of Insertion for kennedy’s class I

24. Path of Insertion for kennedy’s class II

25. Path of Insertion for kennedy’s class III

26. Path of Insertion for kennedy’s class IV

27.  Tripoding the cast:
After the most favorable tilt of the cast
has been selected, it must be recorded
for future reference.
This procedure is referred to as tripod
ing or tripodization.
The simplest method consists of placi
ng crossmarks at three widely spaced p
oints on the dental cast while the vertic
al arm of the surveyor is held at a fixed
vertical position. This will establish thre
e points on the same horizontal plane a
nd permit the cast to be accurately rep
ositioned

28. Placing survey lines:
 The surveyor is also
used to scribe survey
lines on the teeth an
d soft tissues.

29. Locating and marking measured under
cuts:
 Mechanical undercuts must be accura
tely located and appropriately marke
d to permit correct placement of rete
ntive clasps. The depth and position
of the desired undercut will vary with
the material and clasping system to
be used.

30. Design
 The completed design will serve as a bl
ueprint for removable partial denture c
onstruction.
 The mechanical characteristics of the r
emovable partial denture must be cons
idered.
 Components must be neatly drawn and
accurately positioned.
 Most importantly, the completed desig
n must convey essential information to
the laboratory personnel responsible fo
r prosthesis construction.

31.  Principles of design
Basic principles expounded by
Dr A. H. Schmidt in 1953
1.The dentist must have a thorough knowledge
of both the mechanical and biological factors
involved in removable partial denture design.
In addition, the dentist must have a backgro
und in the basic and applied sciences and a
working knowledge of the laws of physics an
d engineering, particularly as they relate to l
evers.
2. The treatment plan must be based on a com
plete examination and diagnosis of the indivi
dual patient.

32. 3. The dentist must correlate the pertinent f
actors and determine a proper plan of tr
eatment.
4. A removable partial denture should restor
e form and function without injury to the
remaining oral structures.
5. A removable partial denture is a form of t
reatment and not a cure. The responsibili
ty of the dentist includes not only placem
ent but also regular recall & maintenanc
e of the prosthesis

33. Philosophy of design
These philosophies of partial denture
design are based upon three approache
s for force distribution. These approach
es may be described as follows:
 1. Stress equalization
 2. Physiologic basing
 3. Broad stress distribution

34. Stress equalization: Advocates of the stress equalization ap
proach to partial denture design emphasize that the vertic
al displaceability of a natural tooth is not as great as that
of the soft tissues covering the edentulous ridge.
-The force transmitted from the RPD to the tooth may be
damaging
-Hence stress directors like simple hinge are interposed be
tween the denture bases & the adjecent clasp assemblies

35. Advantages
 There is need for minimal direct retent
ion because the denture bases
 Stress directors minimize the tipping f
orce on the abutment teeth ,there by l
imiting the bone resorption
Disadvantages
 Stress directors are fragile & costly.
 Require constant maintenance & may
be difficult or impossible to repair.

36. Physiologic basing:
 Proponents of physiologic basing also believ
e that there is a significant disparity betwee
n the apical displaceability of teeth and the
compressibility of the soft tissues.
 However, these practitioners do not believe
that stress directors are necessary to accou
nt for this difference.
 These practitioners believe that equalization
can best be accomplished by recording the
anatomy of the edentulous ridge in its functi
onal form and ensuring that the associated
denture base accurately reflects this anatom
y.

37.  This may be accomplished by depressing t
he mucosa during impression-making proc
edures or by relining the denture base afte
r it has been constructed.
 Advocates of this theory believe that dent
ure bases formed over compressed tissues
will show an increased ability to withstand
vertical forces.
 These practitioners also recognize that the
prosthetic teeth and occlusal rests will be
positioned above the existing occlusal plan
e when the prosthesis is not in function

38. Adaptation of denture base at rest. Whe
n at rest, the denture base is displaced occlus
ally.
Cross-sectional view of
the mandibular ridge in its
anatomic form.
Functional form of the mandibular r
e during impression procedure (phy
logic basing philosophy).
Adaptation of denture
base during function

39. Advantages
 Proponents of this theory believe that de
nture base movement occurring as a res
ult of soft tissue compression and recove
ry exerts a physiologically stimulating eff
ect on the tissues of the residual ridges.
 They also believe that this action promot
es tissue health and reduces the necessit
y for frequent relining or rebasing proced
ures.

40.  The minimal retention requirements associ
ated with physiologic basing result in light
weight prostheses requiring minimal maint
enance and repair.
 The forgiving nature of retentive clasps pr
oduces a significant reduction in the
forces transmitted to the abutment teeth.
 As a result, advocates of this theory believ
e that abutments are retained for
longer periods

41. Disadvantages
 Because the artificial teeth are slightly above
the occlusal plane when the denture is not in
function, there will always be premature cont
acts between the opposing teeth and the pro
sthesis during closure.
 This may be somewhat annoying to the patie
nt and may result in some discomfort.
 It is difficult to produce effective indirect rete
ntion because of the vertical movement of th
e denture and the minimal retention provided
by the direct retainers.

42.  By the time the indirect retainers engage t
he associated rest seats, the direct retaine
rs may have lost contact with their respect
ive abutments. In such instances, indirect
retention is of little consequence.
 In addition to the foregoing factors, prosth
eses constructed in accordance with physi
ologic basing principles are not well stabili
zed against lateral forces. This is related t
o the minimal number of direct retainers u
sed in conjunction with these designs.

43. Broad stress distribution
Advocates of broad stress distribution
believe that trauma to the remaining teeth
and residual ridges can be prevented by
distributing forces over as many teeth and
as much of the soft tissue area as possible.

44.  This is accomplished by using additio
nal rests and clasp assemblies and b
y ensuring that the associated dentur
e bases provide broad coverage

45. Advantages:
 increased contact with the remaining t
eeth and soft tissues minimizes the lat
eral forces on the remaining structures
.
 The use of multiple clasp assemblies in
tended to provide additional resistance
to horizontal movement.
 the resultant prostheses are easier an
d less expensive to construct.

46.  There are no moving parts, so there is les
s danger of fracture and distortion.
 In addition, the rigid components minimiz
e rotational movements and provide exce
llent horizontal stabilization.
 Because of this decreased movement and
increased stability, the residual ridges do
not bear as much of the occlusal load, an
d these partial dentures do not require fr
equent relining or rebasing.

47. Disadvantages:
 The increased coverage provided by
such prostheses may not be accepte
d by some patients.
 This coverage also may complicate
oral hygiene.

48. Clasp placement: Class I

49. Clasp placement: Class II

50. Clasp placement: Class III

51. Clasp placement: Class IV

52.  Design
Procedures:
ARMAMENTARIUM

54.  The surface of the platform tends to oxidize o
ver time. Oxidation prevents the surveying ta
ble from gliding smoothly. This can be correct
ed by wiping the surface of the platform with
an alcohol- or acetone-soaked gauze pad.
 The vertical arm of the surveyor should also
be cleaned with alcohol- or acetone-soaked g
auze pad to remove debris
 If necessary a thin film of light machine oil
may be applied on vertical arm of the survey
or to facilitate easy movement.

56.  The 0.010-inch undercut gauge is used
to position retentive clasps constructed
from chrome alloys and titanium alloys.
 The 0.015-inch,0.020-inch undercut ga
uge may be used to position retentive c
lasps made from wrought wire.
 The 0.030inch undercut gauge is rarely
used for the placement of retentive clas
ps and are more likely to be used to sc
ribe the surface of the cast during tripo
dization procedures.

58.  Colour coding
Color coding pe
rmits improved co
mmunication bet
ween the dentist
and the dental lab
oratory technician
and generally res
ults in improved l
aboratory service.

63.  Step by step procedure:
Examine the occluded diagnostic cast

91. THANK YOU