Surveyors & surveying in dentistry / dentistry dental implants

SURVEYORS & SURVEYING
INDIAN DENTAL ACADEMY
Leader in continuing dental education
www.indiandentalacademy.com
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ContentsContents
Introduction
History & development
Definitions
Types of surveyor
Uses of surveyor
Significance of survey lines
Parts of surveyor
Surveying the diagnostic cast
Surveying the master cast
Recent advances
Conclusion
Bibliography

A partial denture will not succeed unless it is designed andA partial denture will not succeed unless it is designed and
constructed in harmony with all the physiologic andconstructed in harmony with all the physiologic and
mechanical problems present in the patient’s mouth.mechanical problems present in the patient’s mouth.
Haphazard construction, lack of plan, lack of abutmentHaphazard construction, lack of plan, lack of abutment
preparation is a few of the causes of partial denture failures.preparation is a few of the causes of partial denture failures.
INTRODUCTION

The surveying procedure is an integral part of planningThe surveying procedure is an integral part of planning
process which helps the dentist to determine which teeth areprocess which helps the dentist to determine which teeth are
most desirable as abutment for placing the rest seats formost desirable as abutment for placing the rest seats for
maximum support and distribute stresses without excessivemaximum support and distribute stresses without excessive
clasping and tooth coverage.clasping and tooth coverage.
The procedure of surveying requires enormous amount ofThe procedure of surveying requires enormous amount of
learning, but time spent in study is worth, the reward oflearning, but time spent in study is worth, the reward of
success that will follow.success that will follow.

DEFINITIONSDEFINITIONS
SURVEYORSURVEYOR:-:- A paralleling instrument used in construction of aA paralleling instrument used in construction of a
prosthesis to locate and delineate the contours and relative positionsprosthesis to locate and delineate the contours and relative positions
of abutment teeth and associated structures. GPT-8of abutment teeth and associated structures. GPT-8
SURVEYINGSURVEYING:-:- An analysis and comparison of the prominence ofAn analysis and comparison of the prominence of
intra oral contours associated with the fabrication of a dentalintra oral contours associated with the fabrication of a dental
prosthesis.prosthesis.

HISTORY & DEVELOPEMENTHISTORY & DEVELOPEMENT

Until 1920s most RPD wereUntil 1920s most RPD were
designed and constructed by timedesigned and constructed by time
honored method of “eye balling”.Ahonored method of “eye balling”.A
prosthesis made on the basis of educatedprosthesis made on the basis of educated
guesses.guesses.
Before the invention of the dentalBefore the invention of the dental
surveyors dentists evaluate facialsurveyors dentists evaluate facial
contours and undercuts of teeth by visualcontours and undercuts of teeth by visual
survey of dental casts.survey of dental casts.
Dr w.m. Randalls technique 1890

EARLY PARALLELING INSTRUMENTSEARLY PARALLELING INSTRUMENTS
Their purpose is to ensure the parallelism of the properTheir purpose is to ensure the parallelism of the proper
alignment of precesion attachments.alignment of precesion attachments.
Dr.Herman E.S.Chayes 1920 developed the parallelometer.Dr.Herman E.S.Chayes 1920 developed the parallelometer.

Robinson surveyor 1918 Hanau surveyor 1917

Dr. A. J. FortunatiDr. A. J. Fortunati is generally given credit for being the first tois generally given credit for being the first to
employ a mechanical device for determining the relative parallelismemploy a mechanical device for determining the relative parallelism
of two or more tooth surfaces, in the year 1918.of two or more tooth surfaces, in the year 1918.
The first commercial dental surveyor to be offered to theThe first commercial dental surveyor to be offered to the
profession was designed by weinstein and Roth(1923) neysprofession was designed by weinstein and Roth(1923) neys
surveyor.surveyor.
Neys surveyor 1923 Neys surveyor 1938

JELENKO SURVEYORJELENKO SURVEYOR
DEVELOPED BY NOBLE G WILLS 1937DEVELOPED BY NOBLE G WILLS 1937

Original Wills surveyor1929 Kings college surveyor 1940
Electronic surveyor 1958 Columbia parallelomer 1940www.indiandentalacademy.comwww.indiandentalacademy.com

RetentoscopeRetentoscope
Rotating head supports 3 horizontal armsRotating head supports 3 horizontal arms..
a. Conventional surveying arma. Conventional surveying arm
b. Hand piece for millingb. Hand piece for milling
c. Dial-undercut gauge.c. Dial-undercut gauge.

Chayes milling machine Kavo milling machine
Albrecht milling machine
precision dental milling instrumentsprecision dental milling instruments

the highriser surveyor is a pendulum armthe highriser surveyor is a pendulum arm
blockout/survey instrumentblockout/survey instrument
 The arm can freely swing back and forth,The arm can freely swing back and forth,
rotate, or move up or downrotate, or move up or down
 Arm can be locked to hold it at a setArm can be locked to hold it at a set
vertical heightvertical height
 Spring tension is easily adjusted toSpring tension is easily adjusted to
individual preferenceindividual preference
 Heating element attachment is designedHeating element attachment is designed
for easy use and various size tips arefor easy use and various size tips are
availableavailable

The SKYSCRAPER surveyor is a dual
pendulum Electronic Blockout/Survey
ADVANTAGES
The heating element does not have to be
removed when surveying;
By simply rotating the column the new tool is
ready for use

Micro surveyor compassMicro surveyor compass

Today, the Ney and Jelenko (wills) surveyors are the mostToday, the Ney and Jelenko (wills) surveyors are the most
commonly used. Several other types of surveyors have beencommonly used. Several other types of surveyors have been
designed and are in use today, many of these are moredesigned and are in use today, many of these are more
elaborate, costly and possess little advantage than simple typeelaborate, costly and possess little advantage than simple type
of surveyors.of surveyors.

Mc call & Hugel reported that 11 dentalMc call & Hugel reported that 11 dental
surveyors had been featured in scientific exhibitssurveyors had been featured in scientific exhibits
at the American Dental Association’s 1948at the American Dental Association’s 1948
Annual meeting. These were:Annual meeting. These were:
1. Ney 19231. Ney 1923
2. Brown Maier 19252. Brown Maier 1925
3. Wills – 19293. Wills – 1929
4. Lentz – circa 19354. Lentz – circa 1935
5. Linier – 19375. Linier – 1937
6. Ney – 19376. Ney – 1937
7. Franzwa - 19377. Franzwa - 1937
8. Ringle – Hiatt – Smith - 19448. Ringle – Hiatt – Smith - 1944
9. Mc key - 19449. Mc key - 1944
10. Hagman - 194410. Hagman - 1944
11. Roach - 194411. Roach - 1944

Ney surveyorNey surveyor (1937)(1937)
 It is the most widely used Surveyor.It is the most widely used Surveyor.
 In the Ney surveyor the vertical arm isIn the Ney surveyor the vertical arm is
retained by friction with in a fixedretained by friction with in a fixed
bearing.bearing.
 The shaft may be moved up and downThe shaft may be moved up and down
with in this bearing, but remains in anywith in this bearing, but remains in any
vertical position until again moved.vertical position until again moved.

This instrument can be converted into a milling machine byThis instrument can be converted into a milling machine by
clamping a straight hand piece to the surveying arm.clamping a straight hand piece to the surveying arm.
Ney offers two types ofNey offers two types of
clamps for this purpose. Replacing theclamps for this purpose. Replacing the
instrument storage compartment oninstrument storage compartment on
the top of the vertical arm with a ballthe top of the vertical arm with a ball
bearing modified the Ney surveyor,bearing modified the Ney surveyor,
allowing the horizontal arm to rotateallowing the horizontal arm to rotate
360 degree horizontally. This360 degree horizontally. This
modification facilitated surveying andmodification facilitated surveying and
milling.milling.

J .F. Jelenko/wills surveyorJ .F. Jelenko/wills surveyor
 Originally developed by Noble G.Originally developed by Noble G.
Wills, also known as Wills surveyorWills, also known as Wills surveyor
(circa 1937) & marketed by the(circa 1937) & marketed by the
J.F.Jelenko and company.J.F.Jelenko and company.
 Many operators preferred thisMany operators preferred this
instrument because of the springinstrument because of the spring
loaded surveying arm.loaded surveying arm.

They differ principally in that the Jelenko arm swivels where as theThey differ principally in that the Jelenko arm swivels where as the
Ney arm is fixed.Ney arm is fixed.
The objective of this feature is to permit movement of the arm in aThe objective of this feature is to permit movement of the arm in a
horizontal plane rather than to depend entirely on the horizontalhorizontal plane rather than to depend entirely on the horizontal
movement of the cast.movement of the cast.
 The vertical arm of the Jelenko surveyor is spring mounted andThe vertical arm of the Jelenko surveyor is spring mounted and
returns to the top position when released.returns to the top position when released.
 Most recent design of Jelenko surveyor still retained the springMost recent design of Jelenko surveyor still retained the spring
loaded surveying arm.loaded surveying arm.

 Williams surveyor features gimbal stageWilliams surveyor features gimbal stage
table which is adjustable to any desiredtable which is adjustable to any desired
anterior ,posterior, or lateral tilts.anterior ,posterior, or lateral tilts.
 Super structure of this surveyor consists ofSuper structure of this surveyor consists of
jointed arm and spring supported survey rod.jointed arm and spring supported survey rod.
 This surveyor is best suited for placement ofThis surveyor is best suited for placement of
internal attachments rather than analyzinginternal attachments rather than analyzing
and other purposes.and other purposes.
Williams surveyorWilliams surveyor

PARTS OF SURVEYORPARTS OF SURVEYOR
1.1. Platform:-Platform:-on which the base ison which the base is
moved.moved.
2.2. Vertical armVertical arm:-supports the super:-supports the super
structure.structure.
3.3. Horizontal armHorizontal arm:-from which the:-from which the
surveying tools suspends.surveying tools suspends.
4.4. Surveying ArmSurveying Arm: it carries the: it carries the
mandrelmandrel
5.5. Locking deviceLocking device
6.6. Surveying instrumentsSurveying instruments
7.7. Cast Holder:Cast Holder: Table to which theTable to which the
cast is attached.cast is attached.

TOOLS OF SURVEYORTOOLS OF SURVEYOR
• Analyzing rodAnalyzing rodA solid cylindricalA solid cylindrical
metal rod Used to analyze the cast tometal rod Used to analyze the cast to
establish the path of insertion.it is aestablish the path of insertion.it is a
diagnostic surveying tool.diagnostic surveying tool.
Undercut gaugesUndercut gaugesavailable in three sizesavailable in three sizes
Used to measure the undercut on theUsed to measure the undercut on the
cast.cast.
0.01 inch or 0.25mm undercut.0.01 inch or 0.25mm undercut.
0.02 inch or 0.50 mm undercut.0.02 inch or 0.50 mm undercut.
0.03inch or 0.75 mm undercut.0.03inch or 0.75 mm undercut.

Wax knifeWax knife:: used in the late stagesused in the late stages
of RPD construction to eliminateof RPD construction to eliminate
or block out areas of undesirableor block out areas of undesirable
undercuts with wax on the castundercuts with wax on the cast
before the frame work is made.before the frame work is made.
Carbon marker-Carbon marker-
used to scribe the line onused to scribe the line on
the cast.the cast.

USES OF DENTAL SURVEYORUSES OF DENTAL SURVEYOR
1.1. To determine the most desirable path of placement and removalTo determine the most desirable path of placement and removal
for removable partial denture.for removable partial denture.
2.2. To identify proximal tooth surface that are need to be madeTo identify proximal tooth surface that are need to be made
parallel so that they act as guiding planes during placement andparallel so that they act as guiding planes during placement and
removal.removal.
3.3. To measure and locate areas of teeth that may be used forTo measure and locate areas of teeth that may be used for
retention.retention.
4.4. To determine whether tooth and bony areas of interference willTo determine whether tooth and bony areas of interference will
need to be eliminated surgically or by selecting a different path ofneed to be eliminated surgically or by selecting a different path of
placement.placement.
5.5. To determine the most suitable path of placement that willTo determine the most suitable path of placement that will
permit locating retainers and artificial teeth to the best aestheticpermit locating retainers and artificial teeth to the best aesthetic
advantages.advantages.

 To permit accurate mouth preparation to be made to eliminateTo permit accurate mouth preparation to be made to eliminate
dental and osseous contours.dental and osseous contours.
 To record the cast position and its relation to path of placement.To record the cast position and its relation to path of placement.
 To develop axial contours of wax patterns.To develop axial contours of wax patterns.
 Surveying ceramic veneer crownsSurveying ceramic veneer crowns
 Placement of intra coronal retainers (internal attachments).Placement of intra coronal retainers (internal attachments).

Auxiliary usesAuxiliary uses
1.1. Hold the dental hand piece in order to parallel frictionalHold the dental hand piece in order to parallel frictional
attachments in abutment teeth.attachments in abutment teeth.
2.2. Analyze the abutment teeth prior to constructing a fixedAnalyze the abutment teeth prior to constructing a fixed
prosthesis.prosthesis.
3.3. Determine the need for alveoloplasty for an edentulous area ofDetermine the need for alveoloplasty for an edentulous area of
the mouth.the mouth.

Survey linesSurvey lines
 Survey lineSurvey line :: a line produced on a casta line produced on a cast
by a surveyor marking the greatestby a surveyor marking the greatest
prominance of contour in relation toprominance of contour in relation to
the planned path of placement ofthe planned path of placement of
restorationrestoration
 The significance of survey line is thatThe significance of survey line is that
any rigid, nonflexible part of theany rigid, nonflexible part of the
prosthesis must be designed to lieprosthesis must be designed to lie
above the survey line, and onlyabove the survey line, and only
flexible parts may be designed to goflexible parts may be designed to go
below it.below it.
 The survey line also helps to locateThe survey line also helps to locate
areas of undesirable tooth undercutsareas of undesirable tooth undercuts
that must be avoided or eliminated.that must be avoided or eliminated.www.indiandentalacademy.comwww.indiandentalacademy.com

HEIGHT OF CONTOURHEIGHT OF CONTOUR
 The term first used by KENNEDY.The term first used by KENNEDY.
 It represents the greatest bulge ofIt represents the greatest bulge of
diameter of a crown when vieweddiameter of a crown when viewed
from a specific angle or changes asfrom a specific angle or changes as
the vertical position of the tooththe vertical position of the tooth
changed.changed.
 Tipping or tilting the cast will causeTipping or tilting the cast will cause
the height of contour to movethe height of contour to move
accordingly.accordingly.

 DE VAN 1935 referred theDE VAN 1935 referred the
surface of a tooth that is occlusalsurface of a tooth that is occlusal
to the height of contour asto the height of contour as
SUPRA BULGE and surfaceSUPRA BULGE and surface
gingival to the height of contourgingival to the height of contour
as INFRA BULGE.as INFRA BULGE.

Blatterfein classification of survey linesBlatterfein classification of survey lines

Typical survey lineTypical survey line

Atypical A survey lineAtypical A survey line
 Survey line that is too highSurvey line that is too high
( occlusal ) in the near zone( occlusal ) in the near zone
and too low ( gingival ) in theand too low ( gingival ) in the
far zone.far zone.
 Commonly found in buccalCommonly found in buccal
surfaces of canines andsurfaces of canines and
premolars.premolars.
 A reverse circlet clasp is used.A reverse circlet clasp is used.

AATYPICAL B SURVEY LINETYPICAL B SURVEY LINE
 Survey line that is too highSurvey line that is too high
(occlusal) in the near and far zone(occlusal) in the near and far zone
as compared to typical survey lineas compared to typical survey line
 It is frequently found on the buccalIt is frequently found on the buccal
surfaces of the uppers teeth.surfaces of the uppers teeth.

Two factors control clasp designTwo factors control clasp design
1. esthetics 2. periodontium1. esthetics 2. periodontium
1.1. If esthetics is unimportant and periodontium is good- typicalIf esthetics is unimportant and periodontium is good- typical
C clasp may be usedC clasp may be used
2.2. If esthetics is important and periodontium is good-semirigidIf esthetics is important and periodontium is good-semirigid
and flexible 3and flexible 3rdrd
of C clasp may be eliminated on buccal sideof C clasp may be eliminated on buccal side
3.3. If periodontium is weak- ideal contour must be established onIf periodontium is weak- ideal contour must be established on
abutment tooth by operative procedure.abutment tooth by operative procedure.

ATYPICAL C SURVEY LINEATYPICAL C SURVEY LINE
 Survey line that is at gingivalSurvey line that is at gingival
margin in both the near andmargin in both the near and
far zonesfar zones
 For such a survey line underFor such a survey line under
cuts oncuts on
1.1. Distobuccogingival andDistobuccogingival and
distolinguogingival corners ofdistolinguogingival corners of
adjacent teethadjacent teeth
2.2. The far proximal surfaceThe far proximal surface
3.3. The near proximal surfaceThe near proximal surface
may be used to effect primarymay be used to effect primary
retentionretention

COLOR CODINGCOLOR CODING
A color coding system on the diagnostic casts helpsA color coding system on the diagnostic casts helps
prevent confusion on the part of a dental laboratory technicianprevent confusion on the part of a dental laboratory technician
or any one trying to understand the design being proposed.or any one trying to understand the design being proposed.
There is no universally accepted color coding system.There is no universally accepted color coding system.
As result, any system agreed to understood by laboratory andAs result, any system agreed to understood by laboratory and
submitting dentist is considered acceptable.submitting dentist is considered acceptable.

BrownBrown - out line the metallic portion.- out line the metallic portion.
BlueBlue - out line the acrylic portion of the- out line the acrylic portion of the
denture basedenture base
RedRed - to indicate areas on the teeth to be- to indicate areas on the teeth to be
prepared.prepared.
Solid redSolid red - rests and rest seats.- rests and rest seats.
Black pencil and carbon markerBlack pencil and carbon marker - used to- used to
denote the survey linesdenote the survey lines

DETERMINATION OF PATH OFDETERMINATION OF PATH OF
INSERTIONINSERTION
DEFINITIONDEFINITION The direction in which the restoration movesThe direction in which the restoration moves
from the point of initial contact of its rigid parts withfrom the point of initial contact of its rigid parts with
supporting teeth to it’s terminal resting positionsupporting teeth to it’s terminal resting position..

FACTORS INFLUENCING THEFACTORS INFLUENCING THE
PATH OF INSERTIONPATH OF INSERTION

The following four factors must be consideredThe following four factors must be considered
before path of insertion is selected:before path of insertion is selected:
1.Retentive undercuts.1.Retentive undercuts.
2.Interferences.2.Interferences.
3.Esthetics.3.Esthetics.
4.Guiding planes.4.Guiding planes.

RETENTIVE UNDERCUTSRETENTIVE UNDERCUTS
 The first unchangeable rule toThe first unchangeable rule to
remember when surveyingremember when surveying
diagnostic cast for removablediagnostic cast for removable
partial denture is that retentivepartial denture is that retentive
undercuts must be present onundercuts must be present on
abutment teeth when the castabutment teeth when the cast
displays a horizontal tilt.displays a horizontal tilt.
 This is necessary becauseThis is necessary because
dislodging forces are alwaysdislodging forces are always
directed perpendicular to thedirected perpendicular to the
occlusal plane.occlusal plane.

Identifying the most favorable tiltIdentifying the most favorable tilt
Tilting is changing the position of the cast, whichTilting is changing the position of the cast, which
thus changes the long axis of each tooth on thethus changes the long axis of each tooth on the
cast relative to the horizontal plane.cast relative to the horizontal plane.

Change in the tilt then changes the position of surveyChange in the tilt then changes the position of survey
line and location and extent of the undercut.line and location and extent of the undercut.

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

The anterior tilt increaseThe anterior tilt increase
the mesial undercut onthe mesial undercut on
teeth.teeth.

In the posterior tilt,the occlusal plane is lower in posterior region.In the posterior tilt,the occlusal plane is lower in posterior region.

The posterior tilt will increaseThe posterior tilt will increase
the distal undercuts, andthe distal undercuts, and
decrease the mesialdecrease the mesial
undercuts.undercuts.

INTERFERENCESINTERFERENCES
INTERFERENCES IN MANDIBLEINTERFERENCES IN MANDIBLE

Lingually inclined teethLingually inclined teeth

INTERFERENCES IN THE MAXILLAINTERFERENCES IN THE MAXILLA

BONY UNDERCUTSBONY UNDERCUTS

ESTHETICSESTHETICS
 To obtain optimum esthetics, the metal,usually in the form ofTo obtain optimum esthetics, the metal,usually in the form of
clasp arms must be concealed without compromising necessaryclasp arms must be concealed without compromising necessary
support and stability of the prosthesis.support and stability of the prosthesis.
 The artificial teeth must be placed in the most natural positionThe artificial teeth must be placed in the most natural position
possible.possible.

 Avoiding unnecessary display of theAvoiding unnecessary display of the
metal,the tilt of the survey table shouldmetal,the tilt of the survey table should
be such that the survey line on teethbe such that the survey line on teeth
that are visible be as close to thethat are visible be as close to the
gingival margin.gingival margin.
 The ideal position of the clasp for theThe ideal position of the clasp for the
retentive purpose is gingival third ofretentive purpose is gingival third of
the tooth.the tooth.
 When lost anterior teeth are notWhen lost anterior teeth are not
replaced immediately gaps will bereplaced immediately gaps will be
reduced.reduced.

GUIDING PLANESGUIDING PLANES
 Guiding planes are formed fromGuiding planes are formed from
the proximal tooth surfaces of thethe proximal tooth surfaces of the
teeth and are contacted by theteeth and are contacted by the
minor connectors or other rigidminor connectors or other rigid
components of the partial denture.components of the partial denture.
 These planes guide the prosthesisThese planes guide the prosthesis
for removal and placement.for removal and placement.
 the guide planes are in intimatethe guide planes are in intimate
contact with the minorcontact with the minor
connectors,help to stabilizeconnectors,help to stabilize
against the lateral forces.against the lateral forces.

NO OF PATH OF INSERTIONNO OF PATH OF INSERTION

PRESERVING TILT THROUGHPRESERVING TILT THROUGH
TRIPODINGTRIPODING
Once tilt has been selectedOnce tilt has been selected
for given removable partialfor given removable partial
denture design, this tilt shoulddenture design, this tilt should
be preserved, so that it can bebe preserved, so that it can be
reestablished accurately to thereestablished accurately to the
surveying table.surveying table.
This procedure is termedThis procedure is termed
TRIPODINGTRIPODING. This helps in. This helps in
returning the cast to the surveyorreturning the cast to the surveyor
for future reference.for future reference.

Method-2Method-2
Cast position can also beCast position can also be
tripoded by marking linestripoded by marking lines
on the base of the cast withon the base of the cast with
the surveyor and carbonthe surveyor and carbon
marker after the tilt has beenmarker after the tilt has been
selected.selected.
This method has anThis method has an
dis-advantage of smudgingdis-advantage of smudging
the lines during handling ofthe lines during handling of
the castthe cast

SURVEYING THE MASTER CASTSURVEYING THE MASTER CAST

 The master cast for a removableThe master cast for a removable
partial denture is made followingpartial denture is made following
the completion of mouththe completion of mouth
preparation that was indicated frompreparation that was indicated from
design drawn on the diagnosticdesign drawn on the diagnostic
cast.cast.
 Mouth preparation may haveMouth preparation may have
included development of theincluded development of the
guiding planes,contouring the waxguiding planes,contouring the wax
enamel surfaces, and the placementenamel surfaces, and the placement
of the rest seat preparations.of the rest seat preparations.

Before the master cast is sent to the laboratory forBefore the master cast is sent to the laboratory for
construction of removable partial denture frame work, it must beconstruction of removable partial denture frame work, it must be
surveyed to determine whether the mouth preparationsurveyed to determine whether the mouth preparation
accomplished all it as supposed to with the master cast mountedaccomplished all it as supposed to with the master cast mounted
on the surveying table at the same tilt at which the diagnostic caston the surveying table at the same tilt at which the diagnostic cast
was designed.was designed.

Objectives of surveying master castObjectives of surveying master cast
1.1. To select the most suitable path of placement by following mouthTo select the most suitable path of placement by following mouth
preparations that satisfy the requirements of guide planes, retention,preparations that satisfy the requirements of guide planes, retention,
non interference and esthetics.non interference and esthetics.
2.2. To permit measurements of retentive areas and to identify theTo permit measurements of retentive areas and to identify the
location of clasp terminals.location of clasp terminals.
3.3. To locate the undesirable undercut areas that will be crossed by rigidTo locate the undesirable undercut areas that will be crossed by rigid
parts of the restoration during placement and removal,that must beparts of the restoration during placement and removal,that must be
eliminated by blockout.eliminated by blockout.
4.4. To trim blockout material parallel to the path of placement beforeTo trim blockout material parallel to the path of placement before
duplication.duplication.

After establishment of the path of
placement and the location of undercut areas,
any undercut areas that will be crossed by
rigid parts of the denture must be eliminated
by block out. This provides relief under
frame works and ledges on which clasp
patterns are to be placed.
BLOCKING OUT THE MASTER CASTBLOCKING OUT THE MASTER CAST

Parallel blockoutParallel blockout
1.1. cervical to guiding plane surfacescervical to guiding plane surfaces
2.2. Deep interproximal spacesDeep interproximal spaces
3.3. Tissue undercuts crossed byTissue undercuts crossed by
minor connectors and any rigidminor connectors and any rigid
connectorsconnectors
4.4. Beneath bar clasp armsBeneath bar clasp arms
5.5. Hard base plate wax is used forHard base plate wax is used for
this purpose.this purpose.

Shaped blockoutShaped blockout
1.1. On buccal and lingual surfaces to locate wax patterns forOn buccal and lingual surfaces to locate wax patterns for
clasp arms.clasp arms.
2.2. hard baseplate wax is used for blockout.hard baseplate wax is used for blockout.

Arbitrary blockoutArbitrary blockout
1.1. All gingival crevicesAll gingival crevices
2.2. Gross tissue undercuts situatedGross tissue undercuts situated
below areas involved in design ofbelow areas involved in design of
dental framework.dental framework.
3.3. Tissue undercuts distal to castTissue undercuts distal to cast
framework.framework.
4.4. Labial and buccal tooth and tissueLabial and buccal tooth and tissue
undercuts not involved in dentureundercuts not involved in denture
design.design.

Relief areasRelief areas
1.1. Beneath lingual bar connectors orBeneath lingual bar connectors or
the bar portion of linguoplates.the bar portion of linguoplates.
2.2. Areas in which major connectorsAreas in which major connectors
will contact thin tissuewill contact thin tissue
i.i. lingual mandibular ridgeslingual mandibular ridges
ii.ii. elevated palatal raphae.elevated palatal raphae.

CONTOURING THE WAX PATTERNSCONTOURING THE WAX PATTERNS
The surveyor blade is used as a wax carver during this phase.The surveyor blade is used as a wax carver during this phase.
Generally a small amount of undercut 0.02 inch or less isGenerally a small amount of undercut 0.02 inch or less is
sufficient for retentive purposes.sufficient for retentive purposes.

CONTOURING CROWNS AND CASTCONTOURING CROWNS AND CAST
RESTORATIONSRESTORATIONS

Surveying ceramic veneer crownsSurveying ceramic veneer crowns
1.1. Ceramic veneer crowns are oftenCeramic veneer crowns are often
used to restore abutment teeth onused to restore abutment teeth on
which extracoronal direct retainerswhich extracoronal direct retainers
will be placed.will be placed.
2.2. Before the final glaze isBefore the final glaze is
accomplished,the abutment crownsaccomplished,the abutment crowns
should be returned to the surveyorshould be returned to the surveyor
on a full arch cast.on a full arch cast.
3.3. Locate the areas that needLocate the areas that need
recontouring.recontouring.
4.4. The final glaze is accomplishedThe final glaze is accomplished
only after the crowns have beenonly after the crowns have been
recontoured.recontoured.

PLACING INTERNAL ATTACHMENTS ANDPLACING INTERNAL ATTACHMENTS AND
RESTSRESTS

 The surveyor is used to position the intraThe surveyor is used to position the intra
coronal retainers or internal attachments,coronal retainers or internal attachments,
in the wax crown pattern on abutmentin the wax crown pattern on abutment
teeth as the patterns are beingteeth as the patterns are being
formed.Absolute parallelism among allformed.Absolute parallelism among all
the attachment is essential.the attachment is essential.
 A hand piece is attached to the verticalA hand piece is attached to the vertical
arm of the surveyor by means of handarm of the surveyor by means of hand
piece holder.piece holder.
 The internal rests can be machined in theThe internal rests can be machined in the
wax patterns for crowns on the abutmentwax patterns for crowns on the abutment
teeth.teeth.
 After the crowns are cast same handAfter the crowns are cast same hand
piece and burs are used to refine the rests.piece and burs are used to refine the rests.

RECENT ADVANCESRECENT ADVANCES

Electronic surveyingElectronic surveying
A 3-dimensional computer model of a conventional
cast from a patient is obtained using an optical surface
capture device (a scanner).

The shape of number of components of
a removable partial denture framework
was modeled on the 3-dimensional
scan electronically, using computer-
aided design software.

A plastic shape of the components was produced using a RapidA plastic shape of the components was produced using a Rapid
Prototyping machine and used as a pattern.Prototyping machine and used as a pattern.

Use of cad-cam technology to fabricate aUse of cad-cam technology to fabricate a
removable partial denture frameworkremovable partial denture framework
This is the first patientThis is the first patient
fitted cobalt-chromium RPDfitted cobalt-chromium RPD
framework produced byframework produced by
cad-cam and rapid prototypecad-cam and rapid prototype
technology.technology.

ConclusionConclusion
When performing oral rehabilitation with removableWhen performing oral rehabilitation with removable
partial dentures, the objective of the dentist should be to make apartial dentures, the objective of the dentist should be to make a
prosthesis that the patient can easily seat and remove from theprosthesis that the patient can easily seat and remove from the
mouth and yet, when seated, the prosthesis should resist themouth and yet, when seated, the prosthesis should resist the
dislodgment potential caused by masticatory function, especiallydislodgment potential caused by masticatory function, especially
mastication of sticky foods.mastication of sticky foods.

BIBLIOGRAPHYBIBLIOGRAPHY
1.1. Text Book of Partial Dentures – McCracken.Text Book of Partial Dentures – McCracken.
2.2. Text Book of Partial Dentures – Osborne &Text Book of Partial Dentures – Osborne &
Lamee.Lamee.
3.3. Text Book of Partial Dentures – Millers.Text Book of Partial Dentures – Millers.
4.4. Text Book of Partial Dentures – A.A.Grant.Text Book of Partial Dentures – A.A.Grant.
5.5. Clinical removable partial prosthodontics – Kenneth L.Clinical removable partial prosthodontics – Kenneth L.
StewartStewart
6.6. Dental laboratory procedures – Rudd & MorrowDental laboratory procedures – Rudd & Morrow

The history and development of the dental surveyor:The history and development of the dental surveyor:
Part 1:Robert L. Engelmeir, J.P.D.2002;11;11-18.Part 1:Robert L. Engelmeir, J.P.D.2002;11;11-18.
Part 2: “ J.P.D.2002;11:122-130.Part 2: “ J.P.D.2002;11:122-130.
Part 3: “ J.P.D.2004;13:195-202.Part 3: “ J.P.D.2004;13:195-202.
A technique for fabricating patterns for removable partialA technique for fabricating patterns for removable partial
denture frameworks using digitized casts and electronicdenture frameworks using digitized casts and electronic
surveyingsurveying
The Journal of Prosthetic DentistryThe Journal of Prosthetic Dentistry
Volume 91, Issue 1 , January 2004, Pages 85-88Volume 91, Issue 1 , January 2004, Pages 85-88
Surveying removable partial dentures: the importance of guidingSurveying removable partial dentures: the importance of guiding
planes and path of insertion for stabilityplanes and path of insertion for stability
The Journal of Prosthetic DentistryThe Journal of Prosthetic Dentistry
Volume 78, Issue 4Volume 78, Issue 4 , October 1997, Pages 412-418, October 1997, Pages 412-418

Thank youThank you
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Surveyors & surveying in dentistry / dentistry dental implants

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