Surveyors & surveying in prosthodontics / dentistry dental implants

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Surveyors & surveying in prosthodontics / dentistry dental implants

  1. 1. GOOD MORNINGGOOD MORNING INDIAN DENTAL ACADEMY Leader in continuing dental education www.indiandentalacademy.com www.indiandentalacademy.comwww.indiandentalacademy.com
  2. 2. SURVEYORS & SURVEYINGSURVEYORS & SURVEYING www.indiandentalacademy.comwww.indiandentalacademy.com
  3. 3. ContentsContents • IntroductionIntroduction • History & developmentHistory & development • TerminologyTerminology • Types of surveyorTypes of surveyor • Uses of surveyorUses of surveyor • Principles in surveyingPrinciples in surveying • Significance of survey linesSignificance of survey lines • Parts of surveyorParts of surveyor • Surveying the diagnostic castSurveying the diagnostic cast • Surveying the master castSurveying the master cast • Recent advancesRecent advances • ConclusionConclusion • BibliographyBibliography www.indiandentalacademy.comwww.indiandentalacademy.com
  4. 4. www.indiandentalacademy.comwww.indiandentalacademy.com
  5. 5. INTRODUCTIONINTRODUCTION www.indiandentalacademy.comwww.indiandentalacademy.com
  6. 6. • A partial denture will not succeed unless it isA partial denture will not succeed unless it is designed and constructed in harmony with alldesigned and constructed in harmony with all the physiologic and mechanical problemsthe physiologic and mechanical problems present in the patient’s mouth.present in the patient’s mouth. • Haphazard construction, lack of plan, lack ofHaphazard construction, lack of plan, lack of abutment preparation is a few of the causes ofabutment preparation is a few of the causes of partial denture failures.partial denture failures. www.indiandentalacademy.comwww.indiandentalacademy.com
  7. 7. • A typical dental arch for which a partial dentureA typical dental arch for which a partial denture is to be planned, consists of asymmetrical teeth,is to be planned, consists of asymmetrical teeth, separated by edentulous areas and residualseparated by edentulous areas and residual ridges of varied lengths.ridges of varied lengths. • The long axis of the standing teeth usually lackThe long axis of the standing teeth usually lack parallelism with each other, while the surface ofparallelism with each other, while the surface of the crowns of the teeth is irregularly convex inthe crowns of the teeth is irregularly convex in shape.shape. www.indiandentalacademy.comwww.indiandentalacademy.com
  8. 8. • The surveying procedure is an integral part ofThe surveying procedure is an integral part of planning process which helps the dentist toplanning process which helps the dentist to determine which teeth are most desirable asdetermine which teeth are most desirable as abutment for placing the rest seats for maximumabutment for placing the rest seats for maximum support and distribute stresses withoutsupport and distribute stresses without excessive clasping and tooth coverage.excessive clasping and tooth coverage. • The procedure of surveying requires enormousThe procedure of surveying requires enormous amount of learning, but time spent in study isamount of learning, but time spent in study is worth, the reward of success that will follow.worth, the reward of success that will follow. www.indiandentalacademy.comwww.indiandentalacademy.com
  9. 9. HISTORY &HISTORY & DEVELOPEMENTDEVELOPEMENT www.indiandentalacademy.comwww.indiandentalacademy.com
  10. 10. • Until 1950s most RPD were designed andUntil 1950s most RPD were designed and constructed by time honored method of “eyeconstructed by time honored method of “eye balling”.A prosthesis made on the basis ofballing”.A prosthesis made on the basis of educated guesses.educated guesses. • Before the invention of the dental surveyorsBefore the invention of the dental surveyors dentists evaluate facial contours and undercuts ofdentists evaluate facial contours and undercuts of teeth by visual survey of dental casts.teeth by visual survey of dental casts. • This was accomplished by stabilizing the cast onThis was accomplished by stabilizing the cast on table top with wax or impression compound aftertable top with wax or impression compound after the path of placement has been determined.the path of placement has been determined. • Its accuracy is totally dependent on theIts accuracy is totally dependent on the operator’s ability to keep the pencils parallel andoperator’s ability to keep the pencils parallel and steady.steady. • The practitioner would pass a pencil lead overThe practitioner would pass a pencil lead over the facial surfaces of the teeth to develop athe facial surfaces of the teeth to develop a survey line at the greatest diameter of each tooth.survey line at the greatest diameter of each tooth. www.indiandentalacademy.comwww.indiandentalacademy.com
  11. 11. • EARLY PARALLELING INSTRUMENTS:EARLY PARALLELING INSTRUMENTS: •• Paralleling instruments were in use longParalleling instruments were in use long before the development of a dentalbefore the development of a dental surveyor.surveyor. • Their purpose is to assure the properTheir purpose is to assure the proper alignment of precision attachments.alignment of precision attachments. • Dr. Herman E.S.Chayes developed theDr. Herman E.S.Chayes developed the parallelometer. The instrument could beparallelometer. The instrument could be used both intra orally and at the lab benchused both intra orally and at the lab bench to ensure parallelism of precisionto ensure parallelism of precision attachments. It could also be used toattachments. It could also be used to identify non-parallel and undercutidentify non-parallel and undercut surfaces of prepared teeth.surfaces of prepared teeth. www.indiandentalacademy.comwww.indiandentalacademy.com
  12. 12. • The turning point in the partial dentureThe turning point in the partial denture construction from guess work based on clinicalconstruction from guess work based on clinical experience to scientifically based procedure wasexperience to scientifically based procedure was the appearance of dental surveyors in 1918.the appearance of dental surveyors in 1918. www.indiandentalacademy.comwww.indiandentalacademy.com
  13. 13. • Boston in 1918 demonstrated a method for charting correctBoston in 1918 demonstrated a method for charting correct clasp placement by using a parallelometer.clasp placement by using a parallelometer. • Dr. A. J. Fortunati is generally given credit for being the firstDr. A. J. Fortunati is generally given credit for being the first to employ a mechanical device for determining the relativeto employ a mechanical device for determining the relative parallelism of two or more tooth surfaces, in the year 1918.parallelism of two or more tooth surfaces, in the year 1918. •The first commercial dental surveyorThe first commercial dental surveyor to be offered to the profession wasto be offered to the profession was designed 5 years later by engineersdesigned 5 years later by engineers at the J.M.Ney company of Bloomfieldat the J.M.Ney company of Bloomfield Lond(1923).Lond(1923). •First such instrument to be producedFirst such instrument to be produced commercially was NEYS surveyor.commercially was NEYS surveyor. • Next came the WILLS surveyor.Next came the WILLS surveyor. www.indiandentalacademy.comwww.indiandentalacademy.com
  14. 14. ORIGINAL WILLSORIGINAL WILLS SURVEYOR(1929)SURVEYOR(1929) ELECTRONICELECTRONIC SURVEYOR(1958)SURVEYOR(1958) www.indiandentalacademy.comwww.indiandentalacademy.com
  15. 15. • During the succeeding few decades, followingDuring the succeeding few decades, following the introduction of the Ney instrument, a numberthe introduction of the Ney instrument, a number of different surveying instruments were marketedof different surveying instruments were marketed by various dental manufacturers. They are allby various dental manufacturers. They are all constructed on the same basic principle of theconstructed on the same basic principle of the parallelometer.parallelometer. • Today, the Ney and Jelenko (wills) surveyors areToday, the Ney and Jelenko (wills) surveyors are the most commonly used. Several other types ofthe most commonly used. Several other types of surveyors have been designed and are in usesurveyors have been designed and are in use today, many of these are more elaborate, costlytoday, many of these are more elaborate, costly and possess little advantage than simple type ofand possess little advantage than simple type of surveyors.surveyors. www.indiandentalacademy.comwww.indiandentalacademy.com
  16. 16. TYPES OF SURVEYORSTYPES OF SURVEYORS :: • The surveyor marketed by Ney dental international &The surveyor marketed by Ney dental international & J.F.Jelenko and company dominated the market during 20J.F.Jelenko and company dominated the market during 20thth century.century. • By the mid 20By the mid 20thth century many of the dental surveyorscentury many of the dental surveyors had been developed. Mc call & Hugel reported that 11 dentalhad been developed. Mc call & Hugel reported that 11 dental surveyors had been featured in scientific exhibits at the Americansurveyors had been featured in scientific exhibits at the American Dental Association’s 1948 Annual meeting. These were:Dental Association’s 1948 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 - 1944 www.indiandentalacademy.comwww.indiandentalacademy.com
  17. 17. TERMINOLOGYTERMINOLOGY SURVEYORSURVEYOR:-:- A paralleling instrument used inA paralleling instrument used in construction of a dental prosthesis to locate andconstruction of a dental prosthesis to locate and delineate the contours and relate positions ofdelineate the contours and relate positions of abutment teeth and associated structuresabutment teeth and associated structures. GPT-8. GPT-8 SURVEYINGSURVEYING:-:-An analysis and comparison of theAn analysis and comparison of the prominence of intra oral contours associated with theprominence of intra oral contours associated with the fabrication of a dental prosthesis.fabrication of a dental prosthesis. www.indiandentalacademy.comwww.indiandentalacademy.com
  18. 18. • Survey lineSurvey line:-:- A lineA line produced on a cast by aproduced on a cast by a surveyor marking thesurveyor marking the greatest prominence ofgreatest prominence of contour in relation to thecontour in relation to the planned path ofplanned path of placement of aplacement of a restoration.restoration. www.indiandentalacademy.comwww.indiandentalacademy.com
  19. 19. Ney surveyorNey surveyor • It is the most widely used Surveyor.It is the most widely used Surveyor. • In the Ney surveyor the vertical armIn the Ney surveyor the vertical arm is retained by friction with in a fixedis retained by friction with in a fixed bearing.bearing. • The shaft may be moved up andThe shaft may be moved up and down with in this bearing, butdown with in this bearing, but remains in any vertical position untilremains in any vertical position until again moved.again moved. www.indiandentalacademy.comwww.indiandentalacademy.com
  20. 20. • This instrument can be converted into a milling machineThis instrument can be converted into a milling machine by clamping a straight hand piece to the surveying arm.by clamping a straight hand piece to the surveying arm. • Ney offers two types of clamps for this purpose.Ney offers two types of clamps for this purpose. Replacing the instrument storage compartment on theReplacing the instrument storage compartment on the top of the vertical arm with a ball bearing modified thetop of the vertical arm with a ball bearing modified the Ney surveyor, allowing the horizontal arm to rotate 360Ney surveyor, allowing the horizontal arm to rotate 360 degree horizontally. This mid-1960’s modificationdegree horizontally. This mid-1960’s modification facilitated surveying and milling.facilitated surveying and milling. www.indiandentalacademy.comwww.indiandentalacademy.com
  21. 21. 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. www.indiandentalacademy.comwww.indiandentalacademy.com
  22. 22. They differ principally in that the Jelenko arm swivels whereThey differ principally in that the Jelenko arm swivels where as the Ney arm is fixed.as the Ney arm is fixed. •The objective of this feature is to permit movement of the armThe objective of this feature is to permit movement of the arm in a horizontal plane rather than to depend entirely on thein a horizontal plane rather than to depend entirely on the horizontal movement of the cast.horizontal movement of the cast. • The vertical arm of the Jelenko surveyor is spring mountedThe vertical arm of the Jelenko surveyor is spring mounted and returns to the top position when released.and returns to the top position when released. • Most recent design of Jelenko surveyor still retained theMost recent design of Jelenko surveyor still retained the spring loaded surveying arm.spring loaded surveying arm. www.indiandentalacademy.comwww.indiandentalacademy.com
  23. 23. • 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. • Advantage of this table is, center ofAdvantage of this table is, center of rotation always remains constant.rotation always remains constant. • Super structure of this surveyor consistsSuper structure of this surveyor consists of jointed arm and spring supportedof jointed arm and spring supported survey rod.survey rod. • This surveyor is best suited forThis surveyor is best suited for placement of internal attachments ratherplacement of internal attachments rather than analyzing and other purposes.than analyzing and other purposes. Williams surveyorWilliams surveyor www.indiandentalacademy.comwww.indiandentalacademy.com
  24. 24. RetentoscopeRetentoscope • This is a recent addition to theThis is a recent addition to the family of surveyors.family of surveyors. • Rotating head supports 3 horizontalRotating head supports 3 horizontal arms.arms. • a.a. Conventional surveying armConventional surveying arm • b.b. Hand piece for millingHand piece for milling • c.c. Supports a dial-undercut gauge.Supports a dial-undercut gauge. • Work height is attached to verticalWork height is attached to vertical arm. Table can be raised & loweredarm. Table can be raised & lowered during surveying.during surveying. www.indiandentalacademy.comwww.indiandentalacademy.com
  25. 25. • The main purpose of retentoscope is to measure andThe main purpose of retentoscope is to measure and control the undercut planes for clasp retention.control the undercut planes for clasp retention. • This highly scientific instrument prevents theThis highly scientific instrument prevents the employment of excessive or inadequate under cuts andemployment of excessive or inadequate under cuts and effects an equilibration of clasp loads.effects an equilibration of clasp loads. • It exactly determines the degree of infra bulge undercutIt exactly determines the degree of infra bulge undercut being used.being used. www.indiandentalacademy.comwww.indiandentalacademy.com
  26. 26. USES OF DENTAL SURVEYORUSES OF DENTAL SURVEYOR For surveying the diagnostic castFor surveying the diagnostic cast • To determine the most desirable path of placement and removal forTo determine the most desirable path of placement and removal for removable partial denture.removable partial denture. • To identify proximal tooth surface that are need to be made parallel soTo identify proximal tooth surface that are need to be made parallel so that they act as guiding planes during placement and removal.that they act as guiding planes during placement and removal. • To measure and locate areas of teeth that may be used for retention.To measure and locate areas of teeth that may be used for retention. • To determine whether tooth and bony areas of interference will needTo determine whether tooth and bony areas of interference will need to be eliminated surgically or by selecting a different path of placement.to be eliminated surgically or by selecting a different path of placement. • To determine the most suitable path of placement that will permitTo determine the most suitable path of placement that will permit locating retainers and artificial teeth to the best aesthetic advantages.locating retainers and artificial teeth to the best aesthetic advantages.www.indiandentalacademy.comwww.indiandentalacademy.com
  27. 27. • To permit accurate mouth preparation to be made toTo permit accurate mouth preparation to be made to eliminate dental and osseous contours.eliminate dental and osseous contours. • To delineate the heights of contours of all the teeth and toTo delineate the heights of contours of all the teeth and to measure retentive areas.measure retentive areas. • To record the cast position and its relation to path ofTo record the cast position and its relation to path of placement.placement. • To develop axial contours of wax patterns.To develop axial contours of wax patterns. • Surveying ceramic veneer crowns (all surfaces exceptSurveying ceramic veneer crowns (all surfaces except buccal/labial surfaces). The final glaze is done only after thebuccal/labial surfaces). The final glaze is done only after the crowns have been recontoured.crowns have been recontoured. www.indiandentalacademy.comwww.indiandentalacademy.com
  28. 28. • Placement of internal rest seats.Placement of internal rest seats. • To machine guide planes.To machine guide planes. • Surveying the master cast.Surveying the master cast. • To select the most suitable path of insertion.To select the most suitable path of insertion. • To measure retentive areas.To measure retentive areas. • To locate undesirable undercut areasTo locate undesirable undercut areas • To block out the material parallel to path of placementTo block out the material parallel to path of placementwww.indiandentalacademy.comwww.indiandentalacademy.com
  29. 29. Auxiliary usesAuxiliary uses • Hold the dental hand piece in order to parallelHold the dental hand piece in order to parallel frictional attachments in abutment teeth.frictional attachments in abutment teeth. • Analyze the abutment teeth prior to constructingAnalyze the abutment teeth prior to constructing a fixed prosthesis.a fixed prosthesis. • Determine the need for alveoloplasty for anDetermine the need for alveoloplasty for an edentulous area of the mouth.edentulous area of the mouth. www.indiandentalacademy.comwww.indiandentalacademy.com
  30. 30. PRINCIPLES IN SURVEYING:PRINCIPLES IN SURVEYING: • Fundamentally, surveying a tooth consists of locatingFundamentally, surveying a tooth consists of locating accurately the height of its maximum contour in relationaccurately the height of its maximum contour in relation to the plane, in which the model is positioned.to the plane, in which the model is positioned. • If a vertical plane is brought into contact with a convexIf a vertical plane is brought into contact with a convex surface they will contact at the point of maximumsurface they will contact at the point of maximum convexity; and if the convex surface is rotated, still inconvexity; and if the convex surface is rotated, still in contact with the plane, an imaginary line will be traced atcontact with the plane, an imaginary line will be traced at the greatest circumference.the greatest circumference. • This is the survey line. The area of the tooth above thisThis is the survey line. The area of the tooth above this line is non-undercut area and the area below is theline is non-undercut area and the area below is the undercut area.undercut area. www.indiandentalacademy.comwww.indiandentalacademy.com
  31. 31. SIGNIFICANCE OF SURVEY LINESSIGNIFICANCE OF SURVEY LINES www.indiandentalacademy.comwww.indiandentalacademy.com
  32. 32. • The significance of survey line is that anyThe significance of survey line is that any rigid, nonflexible part of the prosthesis mustrigid, nonflexible part of the prosthesis must be designed to lie above the survey line,be designed to lie above the survey line, and only flexible parts may be designed toand only flexible parts may be designed to go below it.go below it. • Normally only the terminal third of theNormally only the terminal third of the retentive clasp is placed gingival to theretentive clasp is placed gingival to the survey line.survey line. • The survey line also helps to locate areasThe survey line also helps to locate areas of undesirable tooth undercuts that must beof undesirable tooth undercuts that must be avoided or eliminated by contouring oravoided or eliminated by contouring or placing restoration on the teeth.placing restoration on the teeth. www.indiandentalacademy.comwww.indiandentalacademy.com
  33. 33. 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. www.indiandentalacademy.comwww.indiandentalacademy.com
  34. 34. • DE VAN 1935 used someDE VAN 1935 used some clarifying terms toclarifying terms to describe retention.describe retention. • He referred to the surfaceHe referred to the surface of a tooth that is occlusalof a tooth that is occlusal to the height of contour asto the height of contour as SUPRA BULGE andSUPRA BULGE and surface inclining cervicallysurface inclining cervically as INFRA BULGE.as INFRA BULGE. www.indiandentalacademy.comwww.indiandentalacademy.com
  35. 35. NEAR ZONE & FAR ZONENEAR ZONE & FAR ZONE • If the buccal and lingual tooth surfaces are divided into twoIf the buccal and lingual tooth surfaces are divided into two halves by vertical line through long axis, the near zone ishalves by vertical line through long axis, the near zone is that half which lies nearer to the saddle and far zone isthat half which lies nearer to the saddle and far zone is away from the saddle.away from the saddle. www.indiandentalacademy.comwww.indiandentalacademy.com
  36. 36. HIGH SURVEY LINEHIGH SURVEY LINE • ThisThis appears much nearer to theappears much nearer to the occlusal than gingival of the tooth inocclusal than gingival of the tooth in both near and far zone.both near and far zone. • It passes from the occlusal third inIt passes from the occlusal third in the near zone to the occlusal third inthe near zone to the occlusal third in the far zone.the far zone. • More commonly it results fromMore commonly it results from inclination of tooth.inclination of tooth. • It is frequently found on the buccalIt is frequently found on the buccal surfaces of the uppers teeth.surfaces of the uppers teeth. • In this condition the undercut will beIn this condition the undercut will be deep and hence a wrought wiredeep and hence a wrought wire clasp is used.clasp is used. www.indiandentalacademy.comwww.indiandentalacademy.com
  37. 37. MEDIUM SURVEY LINEMEDIUM SURVEY LINE • This appears on the buccal orThis appears on the buccal or lingual surface of the tooth,lingual surface of the tooth, approximately equidistanceapproximately equidistance from the occlusal surface andfrom the occlusal surface and gingival margin.gingival margin. • It passes from the occlusal thirdIt passes from the occlusal third in near zone to the middle thirdin near zone to the middle third in far zone.in far zone. • This indicates the use ofThis indicates the use of occlusally approaching clasp.occlusally approaching clasp. www.indiandentalacademy.comwww.indiandentalacademy.com
  38. 38. LOW SURVEY LINELOW SURVEY LINE • Frequently occurs as aFrequently occurs as a result of marked inclinationresult of marked inclination of the tooth, when it isof the tooth, when it is associated with the highassociated with the high survey line of the oppositesurvey line of the opposite side.side. • A tooth surface with the lowA tooth surface with the low survey line cannot bearsurvey line cannot bear retentive clasp arm.retentive clasp arm. www.indiandentalacademy.comwww.indiandentalacademy.com
  39. 39. DIAGONAL SURVEY LINEDIAGONAL SURVEY LINE • Lies nearer the occlusalLies nearer the occlusal surface in near zone of thesurface in near zone of the tooth,to the cervical third oftooth,to the cervical third of the far zone.the far zone. • Commonly found in buccalCommonly found in buccal surfaces of canines andsurfaces of canines and premolars.premolars. • A reverse circlet clasp isA reverse circlet clasp is used.used. www.indiandentalacademy.comwww.indiandentalacademy.com
  40. 40. PARTS OFPARTS OF SURVEYORSURVEYOR • Platform:-Platform:- on which the base ison which the base is moved.moved. • Vertical armVertical arm :-supports the super:-supports the super structure.structure. • Horizontal armHorizontal arm :-from which the:-from which the surveying tools suspends.surveying tools suspends. • Surveying ArmSurveying Arm: it carries the: it carries the mandrelmandrel • Locking deviceLocking device www.indiandentalacademy.comwww.indiandentalacademy.com
  41. 41. TOOLS OF SURVEYORTOOLS OF SURVEYOR • Analyzing rodAnalyzing rodA solid cylindrical metalA solid cylindrical metal rod Used to analyze the cast to establish therod Used to analyze the cast to establish the path of insertion.it is a diagnostic surveyingpath of insertion.it is a diagnostic surveying tool.tool. • Undercut gaugesUndercut gaugesavailable in threeavailable in three colors.Used to measure the undercut on thecolors.Used to measure the undercut on the cast.cast. silver color:-0.01 inch or 0.25mm undercut.silver color:-0.01 inch or 0.25mm undercut. gold color-0.02 inch or 0.50 mm undercut.gold color-0.02 inch or 0.50 mm undercut. black color-0.03inch or 0.75 mm undercut.black color-0.03inch or 0.75 mm undercut. www.indiandentalacademy.comwww.indiandentalacademy.com
  42. 42. • Carbon marker-Carbon marker- used to scribe the line onused to scribe the line on the cast.the cast. • Carbon marker shieldCarbon marker shield • Wax knifeWax knifeused in the lateused in the late stages of RPD construction tostages of RPD construction to eliminate or block out areas ofeliminate or block out areas of undesirable undercuts with waxundesirable undercuts with waxwww.indiandentalacademy.comwww.indiandentalacademy.com
  43. 43. www.indiandentalacademy.comwww.indiandentalacademy.com
  44. 44. SURVEYING THE DIAGNOSTICSURVEYING THE DIAGNOSTIC CASTCAST www.indiandentalacademy.comwww.indiandentalacademy.com
  45. 45. COLOR CODINGCOLOR CODING .. www.indiandentalacademy.comwww.indiandentalacademy.com
  46. 46. • A color coding system for the various parts ofA color coding system for the various parts of the removable partial denture as well as forthe removable partial denture as well as for other items of information that should beother items of information that should be included on the diagnostic casts helpsincluded on the diagnostic casts helps prevent confusion on the part of a dentalprevent confusion on the part of a dental laboratory technician or any one trying tolaboratory technician or any one trying to understand the design being proposed.understand the design being proposed. • There is no universally accepted color codingThere is no universally accepted color coding system. As result, any system agreed tosystem. As result, any system agreed to understood by laboratory and submittingunderstood by laboratory and submitting dentist is considered acceptable.dentist is considered acceptable. www.indiandentalacademy.comwww.indiandentalacademy.com
  47. 47. • Brown crayon pencilBrown crayon pencil out line the metallic portion.out line the metallic portion. • Blue crayon pencilBlue crayon pencil out line the acrylic portion ofout line the acrylic portion of the denture base.the denture base. • Red crayon pencilRed crayon pencil to indicate areas on the teethto indicate areas on the teeth to be prepared.to be prepared. • Solid redSolid red rests and rest seats.rests and rest seats. • Black pencil and carbon markerBlack pencil and carbon marker used to denoteused to denote the survey linesthe survey lines www.indiandentalacademy.comwww.indiandentalacademy.com
  48. 48. www.indiandentalacademy.comwww.indiandentalacademy.com
  49. 49. STEP BY STEPSTEP BY STEP PROCEDURE.PROCEDURE. www.indiandentalacademy.comwww.indiandentalacademy.com
  50. 50. • Examine theExamine the occludedoccluded diagnosticdiagnostic casts.casts. www.indiandentalacademy.comwww.indiandentalacademy.com
  51. 51. • Indicate the proposedIndicate the proposed rest areas by shortrest areas by short vertical lines on thevertical lines on the cast below the toothcast below the tooth with black pencil.with black pencil. www.indiandentalacademy.comwww.indiandentalacademy.com
  52. 52. • Indicate by outliningIndicate by outlining in red any cuspalin red any cuspal relief that will berelief that will be needed to provideneeded to provide adequate occlusaladequate occlusal clearance for restclearance for rest spaces.spaces. www.indiandentalacademy.comwww.indiandentalacademy.com
  53. 53. • Examine the lingualExamine the lingual aspect of the occludedaspect of the occluded casts for adequatecasts for adequate space for lingual rests,space for lingual rests, indirect retainers. Useindirect retainers. Use black pencil forblack pencil for marking.marking. www.indiandentalacademy.comwww.indiandentalacademy.com
  54. 54. • Indicate with pencil, using the following symbols,Indicate with pencil, using the following symbols, the type of tooth replacement.the type of tooth replacement. •Tube tooth.Tube tooth. TT •FacingFacing F.F. •Metal ponticMetal pontic M.M. •Rein forced acrylic ponticRein forced acrylic pontic RAP.RAP. •Place these symbols on thePlace these symbols on the soft tissue portion of the cast,soft tissue portion of the cast, adjacent to the edentulousadjacent to the edentulous area.area. www.indiandentalacademy.comwww.indiandentalacademy.com
  55. 55. • Place the cast on the cast holder at horizontalPlace the cast on the cast holder at horizontal tilt. Examine the teeth to be clapsed fortilt. Examine the teeth to be clapsed for favorable retentive undercuts as well as thefavorable retentive undercuts as well as the shape and contour of the proposed abutmentshape and contour of the proposed abutment teeth.teeth. • If the shape and contour of these teethIf the shape and contour of these teeth necessitate recontouring indicate the locationnecessitate recontouring indicate the location and extent of proposed alteration with redand extent of proposed alteration with red crayon pencil.crayon pencil. • Determine the most favorable tilt of the cast thatDetermine the most favorable tilt of the cast that will permit convenient and proper placement ofwill permit convenient and proper placement of clasps, minor connectors anterior teeth, andclasps, minor connectors anterior teeth, and denture base areas.denture base areas.www.indiandentalacademy.comwww.indiandentalacademy.com
  56. 56. CAST TILTINGCAST TILTING .. www.indiandentalacademy.comwww.indiandentalacademy.com
  57. 57. • Tilting is simply changing the position ofTilting is simply changing the position of the cast, which thus changes the long axisthe cast, which thus changes the long axis of each tooth on the cast relative to theof each tooth on the cast relative to the horizontal plane.horizontal plane. www.indiandentalacademy.comwww.indiandentalacademy.com
  58. 58. • Change in the tilt then changes the position ofChange in the tilt then changes the position of survey line and location and extent of thesurvey line and location and extent of the undercut.undercut. www.indiandentalacademy.comwww.indiandentalacademy.com
  59. 59. • Tilting is used to obtain the most favorable path ofTilting is used to obtain the most favorable path of insertion and also used to increase the desirableinsertion and also used to increase the desirable undercuts and decrease the undesirableundercuts and decrease the undesirable undercuts.undercuts. www.indiandentalacademy.comwww.indiandentalacademy.com
  60. 60. • Through tilting, it isThrough tilting, it is possible to increasepossible to increase the undercuts on onethe undercuts on one side of the tooth whileside of the tooth while decrease them ondecrease them on other side of theother side of the tooth.tooth. www.indiandentalacademy.comwww.indiandentalacademy.com
  61. 61. • It is important to remember that when tilting oneIt is important to remember that when tilting one must examine effect of tilt to establish a moremust examine effect of tilt to establish a more desirable undercuts on other teeth involved indesirable undercuts on other teeth involved in the design.the design. www.indiandentalacademy.comwww.indiandentalacademy.com
  62. 62. • Tilting can also usedTilting can also used to distribute availableto distribute available undercuts to produceundercuts to produce more uniformmore uniform retention through outretention through out the availablethe available abutment.abutment. www.indiandentalacademy.comwww.indiandentalacademy.com
  63. 63. BASIC CAST TILTSBASIC CAST TILTS .. www.indiandentalacademy.comwww.indiandentalacademy.com
  64. 64. • The basic position orThe basic position or tilt of the cast ontilt of the cast on surveyor should besurveyor should be the horizontal tilt.the horizontal tilt. • In the horizontalIn the horizontal tilt,occlusal surfacestilt,occlusal surfaces of the teeth are at orof the teeth are at or near parallel to thenear parallel to the horizontal plane.horizontal plane. www.indiandentalacademy.comwww.indiandentalacademy.com
  65. 65. • In the anterior tilt, theIn the anterior tilt, the anterior teeth areanterior teeth are tilted downwards.tilted downwards. www.indiandentalacademy.comwww.indiandentalacademy.com
  66. 66. • The anterior tiltThe anterior tilt increase the mesialincrease the mesial undercut on teeth.undercut on teeth. www.indiandentalacademy.comwww.indiandentalacademy.com
  67. 67. • In the posterior tilt,the occlusal plane is lower inIn the posterior tilt,the occlusal plane is lower in posterior region.posterior region. www.indiandentalacademy.comwww.indiandentalacademy.com
  68. 68. • The posterior tilt willThe posterior tilt will increase the distalincrease the distal undercuts, andundercuts, and decrease the mesialdecrease the mesial undercuts.undercuts. www.indiandentalacademy.comwww.indiandentalacademy.com
  69. 69. • In the right lateral tiltIn the right lateral tilt right portion of theright portion of the cast tiltedcast tilted downwards.downwards. • The right lateral tiltThe right lateral tilt increase undercuts onincrease undercuts on buccal surfaces ofbuccal surfaces of right side.right side. • Buccal under cuts areBuccal under cuts are reduced on left side.reduced on left side. www.indiandentalacademy.comwww.indiandentalacademy.com
  70. 70. • In the left lateral tilt the left portion of the castIn the left lateral tilt the left portion of the cast tilted downwards.tilted downwards. www.indiandentalacademy.comwww.indiandentalacademy.com
  71. 71. • Left lateral tilt willLeft lateral tilt will increase undercuts onincrease undercuts on buccal surface of leftbuccal surface of left and will decreaseand will decrease undercuts on buccalundercuts on buccal surfaces of right.surfaces of right. www.indiandentalacademy.comwww.indiandentalacademy.com
  72. 72. DETERMINATION OF PATH OFDETERMINATION OF PATH OF INSERTIONINSERTION www.indiandentalacademy.comwww.indiandentalacademy.com
  73. 73. • DEFINITIONDEFINITION :The direction in which the:The direction in which the restoration moves from the point of initialrestoration moves from the point of initial contact of its rigid parts with supportingcontact of its rigid parts with supporting teeth to it’s terminal resting position.teeth to it’s terminal resting position. www.indiandentalacademy.comwww.indiandentalacademy.com
  74. 74. • The principle thatThe principle that governs the functiongoverns the function of a dental surveyorof a dental surveyor requires that therequires that the surveying rod (stylus)surveying rod (stylus) be at a 90 degreebe at a 90 degree angle (perpendicular)angle (perpendicular) to the platform of theto the platform of the surveyor.surveyor. www.indiandentalacademy.comwww.indiandentalacademy.com
  75. 75. • positioning the castpositioning the cast with the occlusalwith the occlusal plane parallel to theplane parallel to the platform of theplatform of the surveyor establishessurveyor establishes a perpendiculara perpendicular relation between therelation between the surveying rod and thesurveying rod and the occlusal plane, whichocclusal plane, which would accommodatewould accommodate a path of insertiona path of insertion perpendicular to theperpendicular to the occlusal plane.occlusal plane. 19.jpg www.indiandentalacademy.comwww.indiandentalacademy.com
  76. 76. • The selection of a path perpendicular to theThe selection of a path perpendicular to the occlusal plane is considered to be favorableocclusal plane is considered to be favorable because, against the advice of their dentist,because, against the advice of their dentist, many patients insert their RPD’ s with a bitingmany patients insert their RPD’ s with a biting force and because this orientation of the castforce and because this orientation of the cast facilitates the mouth preparation necessary tofacilitates the mouth preparation necessary to make the prosthesis function as it is intended,make the prosthesis function as it is intended, once it is fabricated.once it is fabricated. www.indiandentalacademy.comwww.indiandentalacademy.com
  77. 77. • Regardless of the path ofRegardless of the path of insertion determined forinsertion determined for any RPD, there is alwaysany RPD, there is always a potential path ofa potential path of dislodgment (PPD)dislodgment (PPD) resulting from masticatoryresulting from masticatory function that pulls thefunction that pulls the prosthesis in a directionprosthesis in a direction perpendicular to theperpendicular to the occlusal plane time whenocclusal plane time when the patient completesthe patient completes each chewing stroke andeach chewing stroke and begins the next one, afterbegins the next one, after closing his mouth, opensclosing his mouth, opens it again in theit again in the continuation of thecontinuation of the masticatory cycle.masticatory cycle. 18.jpg www.indiandentalacademy.comwww.indiandentalacademy.com
  78. 78. • Thus the path of insertion (PI) is ofThus the path of insertion (PI) is of fundamental clinical importancefundamental clinical importance because it predetermines thebecause it predetermines the placement of clasp arms inplacement of clasp arms in retentive undercuts, whichretentive undercuts, which provides the retention and helps inprovides the retention and helps in stabilizing the prosthesis duringstabilizing the prosthesis during function.function. • This clasp design will provideThis clasp design will provide adequate retention and stabilityadequate retention and stability because the relatively long guidebecause the relatively long guide planes at this PI are parallel toplanes at this PI are parallel to each other and the facialeach other and the facial undercuts for clasp retention areundercuts for clasp retention are approximately equal to each otherapproximately equal to each other and are equidistant below theand are equidistant below the survey line.survey line. www.indiandentalacademy.comwww.indiandentalacademy.com
  79. 79. • There is a considerable undercut onThere is a considerable undercut on the facial surface of the abutment onthe facial surface of the abutment on the left side and total absence of anthe left side and total absence of an undercut on the abutment on theundercut on the abutment on the right side.right side. A framework designed at this zeroA framework designed at this zero inclination would not have adequateinclination would not have adequate retention.retention. • Inclining the cast to the right sideInclining the cast to the right side should result in a better distributionshould result in a better distribution of the undercut surfaces betweenof the undercut surfaces between the two abutments, creating athe two abutments, creating a medium undercut surface on themedium undercut surface on the facial surface of each abutment.facial surface of each abutment. 21.jpg www.indiandentalacademy.comwww.indiandentalacademy.com
  80. 80. 24.jpg 26.jpg www.indiandentalacademy.comwww.indiandentalacademy.com
  81. 81. • If the edentulous space is tooth bounded it will haveIf the edentulous space is tooth bounded it will have only one path of insertion.only one path of insertion. • If the edentulous space is distal extension bases onIf the edentulous space is distal extension bases on both sided the path of insertion are multiple.both sided the path of insertion are multiple. • If it is both tooth bounded and tissue bounded theIf it is both tooth bounded and tissue bounded the path of insertion is determined by modificationpath of insertion is determined by modification space.space. • The component of the denture that governs theThe component of the denture that governs the path of insertion is the minor connector that joinspath of insertion is the minor connector that joins the clasps to the major connector.the clasps to the major connector. www.indiandentalacademy.comwww.indiandentalacademy.com
  82. 82. • The minor connector is normally the only portion ofThe minor connector is normally the only portion of the prosthesis that contacts the guiding planes onthe prosthesis that contacts the guiding planes on the teeth;it should be in continual contact with thethe teeth;it should be in continual contact with the guiding planes through out process of seating andguiding planes through out process of seating and removing the partial denture.removing the partial denture. • The body and the shoulders of the clasp may exertThe body and the shoulders of the clasp may exert some influence on the path of insertionsome influence on the path of insertion www.indiandentalacademy.comwww.indiandentalacademy.com
  83. 83. FACTORS INFLUENCING THEFACTORS INFLUENCING THE PATH OF INSERTIONPATH OF INSERTION .. www.indiandentalacademy.comwww.indiandentalacademy.com
  84. 84. The following four factors must be considered beforeThe following four factors must be considered before path of insertion is selected: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. www.indiandentalacademy.comwww.indiandentalacademy.com
  85. 85. 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. www.indiandentalacademy.comwww.indiandentalacademy.com
  86. 86. • With the analyzing rod attached toWith the analyzing rod attached to the vertical arm,each abutmentthe vertical arm,each abutment tooth is examined for the presencetooth is examined for the presence of retentive undercuts.of retentive undercuts. • Resistance to this dislodging forceResistance to this dislodging force must be present when the cast is atmust be present when the cast is at a horizontal position.a horizontal position. • The surveying procedure is always started with the cast to beThe surveying procedure is always started with the cast to be analyzed positioned in the cast holder so that the occlusalanalyzed positioned in the cast holder so that the occlusal surfaces of the remaining teeth are parallel to the surveyingsurfaces of the remaining teeth are parallel to the surveying table or base of the surveyor.table or base of the surveyor. www.indiandentalacademy.comwww.indiandentalacademy.com
  87. 87. • If retentive undercuts are not presentIf retentive undercuts are not present they must be created.The obviousthey must be created.The obvious method is by the use of full crown ormethod is by the use of full crown or porcelain bonded to metal.porcelain bonded to metal. • If either of these types of crowns areIf either of these types of crowns are planned, it must be placed on theplanned, it must be placed on the surveyor as it is being formed andsurveyor as it is being formed and contoured to satisfy the requirement ofcontoured to satisfy the requirement of partial denture.partial denture. • Enamel surfaces are contoured inEnamel surfaces are contoured in limited circumstances to provide orlimited circumstances to provide or improve retentive undercuts.improve retentive undercuts. www.indiandentalacademy.comwww.indiandentalacademy.com
  88. 88. • Ideally proposed abutment teeth should haveIdeally proposed abutment teeth should have 0.010 inch undercut at the most desirable0.010 inch undercut at the most desirable location,either the distobuccal or mesiobuccal linelocation,either the distobuccal or mesiobuccal line angle and in the gingival third of clinical crown ofangle and in the gingival third of clinical crown of the tooth.the tooth. • Once retentive undercuts have been found at theOnce retentive undercuts have been found at the horizontal tilt,the tilt may be changed to alter thehorizontal tilt,the tilt may be changed to alter the amount of undercut on any given tooth.amount of undercut on any given tooth. • It must be remembered changing the tilt to alterIt must be remembered changing the tilt to alter the amount of undercut on one tooth will affect thethe amount of undercut on one tooth will affect the undercuts on the remaining teeth.undercuts on the remaining teeth. www.indiandentalacademy.comwww.indiandentalacademy.com
  89. 89. • The tilt is given because the retentive and reciprocalThe tilt is given because the retentive and reciprocal arms are placed gingival or occlusal third of thearms are placed gingival or occlusal third of the abutment, which in turn helps in the esthetic resultabutment, which in turn helps in the esthetic result and also helps in reducing the torquing or rotationaland also helps in reducing the torquing or rotational forces.forces. www.indiandentalacademy.comwww.indiandentalacademy.com
  90. 90. INTERFERENCESINTERFERENCES INTERFERENCES IN MANDIBLEINTERFERENCES IN MANDIBLE :: • Mandibular tori can produce significantMandibular tori can produce significant problems in RPD Therapy,surgicalproblems in RPD Therapy,surgical removal is needed.removal is needed. • One of the greatest errors in planning is,One of the greatest errors in planning is, attempting to position the majorattempting to position the major connector to avoid a lingual torusconnector to avoid a lingual torus especially if a lingual bar is planned asespecially if a lingual bar is planned as the major connector.the major connector. • Relief or nonrigid connector is theRelief or nonrigid connector is the alternative planning for the framework.Butalternative planning for the framework.But the thickness of the bar is compromisedthe thickness of the bar is compromised and damage to the remaining teeth ifand damage to the remaining teeth if nonrigid connector is used.nonrigid connector is used.www.indiandentalacademy.comwww.indiandentalacademy.com
  91. 91. • Another frequent problem commonly seen isAnother frequent problem commonly seen is lingually inclined teeth.lingually inclined teeth. • If the lingually inclined teeth are bilateral,theIf the lingually inclined teeth are bilateral,the space available for the major connector isspace available for the major connector is reduced.This influences the tongue space.reduced.This influences the tongue space. • One answer to this problem would be to plan aOne answer to this problem would be to plan a labial bar major connector in place of linguallabial bar major connector in place of lingual bar.bar. • The bulk of the labial bar causes anThe bulk of the labial bar causes an comfortable and unattractive plumping of thecomfortable and unattractive plumping of the lower lip.lower lip. • Another answer to this problem is contouringAnother answer to this problem is contouring the lingual surfaces or placing the restorations.the lingual surfaces or placing the restorations. www.indiandentalacademy.comwww.indiandentalacademy.com
  92. 92. INTERFERENCES IN THEINTERFERENCES IN THE MAXILLA:MAXILLA: • One of the major sources ofOne of the major sources of interferences in maxilla is torusinterferences in maxilla is torus palatinus.palatinus. • Torus interferences with theTorus interferences with the placement of major connector.placement of major connector. • Usually the design of majorUsually the design of major connector must be changed toconnector must be changed to avoid the torus;if not possibleavoid the torus;if not possible surgical intervention must besurgical intervention must be accomplished.accomplished. www.indiandentalacademy.comwww.indiandentalacademy.com
  93. 93. • Bony exostoses orBony exostoses or undercuts buccal to theundercuts buccal to the posterior edentulous ridgeposterior edentulous ridge are encounteredare encountered frequently.frequently. • Surgical procedures areSurgical procedures are followed for thesefollowed for these undercuts.undercuts. • Buccally or facially tippedBuccally or facially tipped teeth are also source ofteeth are also source of interferences.interferences. www.indiandentalacademy.comwww.indiandentalacademy.com
  94. 94. • If these buccally tilted teeth are present on one sideIf these buccally tilted teeth are present on one side of the arch tilting the surveying table away from theof the arch tilting the surveying table away from the teeth may lower the height of contour sufficiently toteeth may lower the height of contour sufficiently to permit the clasp to be located in a nearly idealpermit the clasp to be located in a nearly ideal position.position. • If these inclined teeth are present both sides ofIf these inclined teeth are present both sides of arch,changing the tilt of the cast will have no helpfularch,changing the tilt of the cast will have no helpful effect. If the tipping is not severe,contour the enameleffect. If the tipping is not severe,contour the enamel surface or full crown restoration is given in case ofsurface or full crown restoration is given in case of severe tipping.severe tipping. www.indiandentalacademy.comwww.indiandentalacademy.com
  95. 95. ESTHETICSESTHETICS • To obtain optimum esthetics, the metal,usually inTo obtain optimum esthetics, the metal,usually in the form of clasp arms must be concealed withoutthe form of clasp arms must be concealed without compromising necessary support and stability ofcompromising necessary support and stability of the prosthesis.the prosthesis. • The artificial teeth must be placed in the mostThe artificial teeth must be placed in the most natural position possible.natural position possible. www.indiandentalacademy.comwww.indiandentalacademy.com
  96. 96. • Avoiding unnecessary display of theAvoiding unnecessary display of the metal,the tilt of the survey tablemetal,the tilt of the survey table should be such that the survey lineshould be such that the survey line on teeth that are visible be as closeon teeth that are visible be as close to the gingival margin.to the gingival margin. • The ideal position of the clasp forThe ideal position of the clasp for the retentive purpose is gingivalthe retentive purpose is gingival third of the tooth.third of the tooth. • When lost anterior teeth are notWhen lost anterior teeth are not replaced immediately, the spacereplaced immediately, the space remaining is frequently less than theremaining is frequently less than the space occupied by the missingspace occupied by the missing because of mesial drifting ofbecause of mesial drifting of remaining teeth.remaining teeth. www.indiandentalacademy.comwww.indiandentalacademy.com
  97. 97. • To counter this esthetic shortcoming,the use ofTo counter this esthetic shortcoming,the use of dental surveyor is necessary.dental surveyor is necessary. • When determining the final tilt of the cast, theWhen determining the final tilt of the cast, the space of missing anterior teeth must be given highspace of missing anterior teeth must be given high priority.priority. • Tooth bounded partial denture always determinesTooth bounded partial denture always determines the path of insertion. This means that the surveyorthe path of insertion. This means that the surveyor must be used to determine the whether tooth has tomust be used to determine the whether tooth has to contoured, or disking in the proximal surfaces hascontoured, or disking in the proximal surfaces has to be done to restore the mesiodistal width of theto be done to restore the mesiodistal width of the missing teeth.missing teeth. www.indiandentalacademy.comwww.indiandentalacademy.com
  98. 98. • The choice is the placement of the full crownThe choice is the placement of the full crown restorations.restorations. • The surveyor is necessary for the determining theThe surveyor is necessary for the determining the amount of recontouring that will be needed toamount of recontouring that will be needed to reduce these undesirable undercuts and to re-reduce these undesirable undercuts and to re- establish the space required for optimum results.establish the space required for optimum results. www.indiandentalacademy.comwww.indiandentalacademy.com
  99. 99. 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. • When denture is completelyWhen denture is completely seated in the mouth, the guideseated in the mouth, the guide planes are in intimate contact withplanes are in intimate contact with the minor connectors,help tothe minor connectors,help to stabilize against the lateral forces.stabilize against the lateral forces. www.indiandentalacademy.comwww.indiandentalacademy.com
  100. 100. • They also help to protect the weakened teeth fromThey also help to protect the weakened teeth from destructive forces.destructive forces. • The surveyor is used to locate the potentialThe surveyor is used to locate the potential surfaces of the teeth that can be converted tosurfaces of the teeth that can be converted to guiding planes by selective grinding.guiding planes by selective grinding. • The teeth for which guiding planes are plannedThe teeth for which guiding planes are planned receive cast restoration, the wax patterns should bereceive cast restoration, the wax patterns should be shaped by the surveyor with their surfaces parallelshaped by the surveyor with their surfaces parallel to the path of insertion.to the path of insertion. www.indiandentalacademy.comwww.indiandentalacademy.com
  101. 101. 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 canbe preserved, so that it can be reestablished accuratelybe reestablished accurately to the surveying table.to the surveying table. • This procedure is termedThis procedure is termed TRIPOIDING. This helps inTRIPOIDING. This helps in returning the cast to thereturning the cast to the surveyor for future reference.surveyor for future reference. www.indiandentalacademy.comwww.indiandentalacademy.com
  102. 102. Different methods to doDifferent methods to do tripoding:-tripoding:- METHOD 1METHOD 1 • Place 3 widely divergent dotsPlace 3 widely divergent dots on the tissue surface of the caston the tissue surface of the cast with the tip of the carbonwith the tip of the carbon marker, having the vertical ofmarker, having the vertical of the surveyor in a lockedthe surveyor in a locked position.position. • Preferably these dots shouldPreferably these dots should not be placed on the areas ofnot be placed on the areas of the cast involved in frame workthe cast involved in frame work designing.designing. www.indiandentalacademy.comwww.indiandentalacademy.com
  103. 103. • On returning the cast toOn returning the cast to the surveyor, it may bethe surveyor, it may be tilted until the tip of thetilted until the tip of the surveyor blade onsurveyor blade on diagnostic stylus againdiagnostic stylus again contacts the 3 dots in thecontacts the 3 dots in the same place.same place. • This method is tripoiding.This method is tripoiding. www.indiandentalacademy.comwww.indiandentalacademy.com
  104. 104. METHOD 2METHOD 2 • Score two sides and dorsal aspect of the base ofScore two sides and dorsal aspect of the base of the cast with a sharp instrument held against thethe cast with a sharp instrument held against the surveyor blade.surveyor blade. • By tilting the cast until all three lines are againBy tilting the cast until all three lines are again parallel to the surveyor blade, the original positionparallel to the surveyor blade, the original position can be re-established.can be re-established. • Fortunately the scratch lines will be reproduced inFortunately the scratch lines will be reproduced in duplication, there by permitting any duplicate castduplication, there by permitting any duplicate cast to be related to the surveyor in a similar manner.to be related to the surveyor in a similar manner. www.indiandentalacademy.comwww.indiandentalacademy.com
  105. 105. Method-3Method-3 • Cast position can also beCast position can also be tripoded by marking linestripoded by marking lines on the base of the caston the base of the cast with the surveyor andwith the surveyor and carbon marker after thecarbon marker after the tilt has been selected.tilt has been selected. • This method has an dis-This method has an dis- advantage of smudgingadvantage of smudging the lines during handlingthe lines during handling of the castof the cast www.indiandentalacademy.comwww.indiandentalacademy.com
  106. 106. • Place the carbonPlace the carbon marker in the verticalmarker in the vertical arm of the surveyorarm of the surveyor and scribe the surveyand scribe the survey line on teeth that willline on teeth that will be contacted on thebe contacted on the diagnostic cast.diagnostic cast. www.indiandentalacademy.comwww.indiandentalacademy.com
  107. 107. • With red pencil drawWith red pencil draw in the extent of restin the extent of rest areas to be preparedareas to be prepared in the mouthin the mouth www.indiandentalacademy.comwww.indiandentalacademy.com
  108. 108. • If teeth requireIf teeth require recontouring outline inrecontouring outline in red,exact location andred,exact location and extent of proposedextent of proposed alterationalteration www.indiandentalacademy.comwww.indiandentalacademy.com
  109. 109. • Out line the exactOut line the exact positioning of the denturepositioning of the denture base area. Blue pencilbase area. Blue pencil indicates acrylic base;indicates acrylic base; Brown pencil indicatesBrown pencil indicates metal denture base.metal denture base. • With brown pencil outlineWith brown pencil outline the frame work design tothe frame work design to harmonize and join theharmonize and join the major connector, restmajor connector, rest seats, indirect retainersseats, indirect retainers and minor connectors.and minor connectors. www.indiandentalacademy.comwww.indiandentalacademy.com
  110. 110. • Replace the carbonReplace the carbon marker withmarker with appropriate under cutappropriate under cut gaugesgauges www.indiandentalacademy.comwww.indiandentalacademy.com
  111. 111. • Complete designedComplete designed casts.casts. www.indiandentalacademy.comwww.indiandentalacademy.com
  112. 112. SURVEYING THE MASTERSURVEYING THE MASTER CASTCAST www.indiandentalacademy.comwww.indiandentalacademy.com
  113. 113. • The master cast for aThe master cast for a removable partial denture isremovable partial denture is made following the completionmade following the completion of mouth preparation that wasof mouth preparation that was indicated from design drawn onindicated from design drawn on the diagnostic cast.the diagnostic cast. • Mouth preparation may haveMouth preparation may have included the placement ofincluded the placement of crowns or other restorations oncrowns or other restorations on abutment teeth,theabutment teeth,the development of the guidingdevelopment of the guiding planes,contouring the waxplanes,contouring the wax enamel surfaces, and theenamel surfaces, and the placement of the rest seatplacement of the rest seat preparations.preparations. www.indiandentalacademy.comwww.indiandentalacademy.com
  114. 114. • Before the master cast is sent to the laboratory forBefore the master cast is sent to the laboratory for construction of removable partial denture frameconstruction of removable partial denture frame work, it must be surveyed to determine whether thework, it must be surveyed to determine whether the mouth preparation accomplished all it as supposedmouth preparation accomplished all it as supposed to with the master cast mounted on the surveyingto with the master cast mounted on the surveying table at the same tilt at which the diagnostic casttable at the same tilt at which the diagnostic cast was designed.was designed. www.indiandentalacademy.comwww.indiandentalacademy.com
  115. 115. Objectives of surveying master castObjectives of surveying master cast • To select the most suitable path of placement by followingTo select the most suitable path of placement by following mouth preparations that satisfy the requirements of guidemouth preparations that satisfy the requirements of guide planes, retention, non interference and esthetics.planes, retention, non interference and esthetics. • 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. • To locate the undesirable undercut areas that will be crossedTo locate the undesirable undercut areas that will be crossed by rigid parts of the restoration during placement andby rigid parts of the restoration during placement and removal,that must be eliminated by blockout.removal,that must be eliminated by blockout. • To trim blockout material parallel to the path of placementTo trim blockout material parallel to the path of placement before duplication.before duplication. www.indiandentalacademy.comwww.indiandentalacademy.com
  116. 116. . BLOCKING OUT THE MASTER CAST 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. Parallel block out is necessary cervical to guiding plane surfaces and overall undercut areas that will be crossed by major or minor connectors. Hard base plate wax is used for this purpose. www.indiandentalacademy.comwww.indiandentalacademy.com
  117. 117. • Shaped blockoutShaped blockout :: On buccal and lingualOn buccal and lingual surfaces to locate plastic orsurfaces to locate plastic or wax patterns for clasp arms,wax patterns for clasp arms, hard baseplate wax is usedhard baseplate wax is used for blockout.for blockout. www.indiandentalacademy.comwww.indiandentalacademy.com
  118. 118. Arbitrary blockoutArbitrary blockout • Sites-Sites- • All gingival crevicesAll gingival crevices • Gross tissue undercuts situated below areasGross tissue undercuts situated below areas involved in design of dental framework.involved in design of dental framework. • Tissue undercuts distal to cast framework.Tissue undercuts distal to cast framework. • Labial and buccal tooth and tissue undercutsLabial and buccal tooth and tissue undercuts not involved in denture design.not involved in denture design. www.indiandentalacademy.comwww.indiandentalacademy.com
  119. 119. Relief areas:Relief areas: • Sites-Sites- • Beneath lingual bar connectors or theBeneath lingual bar connectors or the bar portion of linguoplates.bar portion of linguoplates. • Areas in which major connectors willAreas in which major connectors will contact thin tissuecontact thin tissue • usually found on lingual or mandibularusually found on lingual or mandibular ridges and elevated palatal raphae.ridges and elevated palatal raphae. • Hard baseplate wax is used forHard baseplate wax is used for blockout.blockout. • Adhesives wax is sealed to cast,shouldAdhesives wax is sealed to cast,should be wider than major connector to bebe wider than major connector to be placed on it.placed on it. www.indiandentalacademy.comwww.indiandentalacademy.com
  120. 120. . DESIGN OF PROSTHESIS When all the mouth preparation has been completed, the definitive design of the prosthesis is drawn on the cast and then processed.     www.indiandentalacademy.comwww.indiandentalacademy.com
  121. 121. CONTOURING THE WAXCONTOURING THE WAX PATTRENSPATTRENS www.indiandentalacademy.comwww.indiandentalacademy.com
  122. 122. • The surveyor blade is used as a waxThe surveyor blade is used as a wax carver during this phase.carver during this phase. • The proposed path of placement may beThe proposed path of placement may be maintained throughout the preparation ofmaintained throughout the preparation of cast restorations for abutment teeth.cast restorations for abutment teeth. • Guiding planes on all proximal surfacesGuiding planes on all proximal surfaces of wax patterns adjacent to theof wax patterns adjacent to the edentulous areas should be madeedentulous areas should be made parallel.parallel. • The surfaces of restoration on whichThe surfaces of restoration on which reciprocal and stabilizing components willreciprocal and stabilizing components will be placed should be contoured to permitbe placed should be contoured to permit their location well below occlusal surfacestheir location well below occlusal surfaceswww.indiandentalacademy.comwww.indiandentalacademy.com
  123. 123. • Those surfaces ofThose surfaces of restorations that are torestorations that are to provide retention for theprovide retention for the clasp arms should beclasp arms should be contoured so that retentivecontoured so that retentive clasps may be placed in theclasps may be placed in the cervical third of the crowncervical third of the crown and to the best estheticand to the best esthetic advantage.advantage. • Generally a small amountGenerally a small amount of undercut 0.02 inch orof undercut 0.02 inch or less is sufficient forless is sufficient for retentive purposes.retentive purposes. www.indiandentalacademy.comwww.indiandentalacademy.com
  124. 124. CONTOURING CROWNS ANDCONTOURING CROWNS AND CAST RESTORATIONSCAST RESTORATIONS www.indiandentalacademy.comwww.indiandentalacademy.com
  125. 125. • Surveying ceramic veneerSurveying ceramic veneer crownscrowns:: • Ceramic veneer crowns are often used toCeramic veneer crowns are often used to restore abutment teeth on whichrestore abutment teeth on which extracoronal direct retainers will beextracoronal direct retainers will be placed.placed. • The surveyor is used to contour all areasThe surveyor is used to contour all areas of the wax pattern except the buccal orof the wax pattern except the buccal or labial surface.labial surface. • Using a porcelain veneer restoration is toUsing a porcelain veneer restoration is to develop an esthetic replica of a naturaldevelop an esthetic replica of a natural tooth.tooth. • Ceramic veneer portion can be fabricatedCeramic veneer portion can be fabricated exactly to the form required for theexactly to the form required for the planned placement of retentive claspplanned placement of retentive clasp arms without some reshaping witharms without some reshaping with stones.stones. www.indiandentalacademy.comwww.indiandentalacademy.com
  126. 126. • Before the final glaze is accomplished,the abutmentBefore the final glaze is accomplished,the abutment crowns should be returned to the surveyor on a full archcrowns should be returned to the surveyor on a full arch cast.cast. • Locate the areas that need recontouring.Locate the areas that need recontouring. • The final glaze is accomplished only after the crownsThe final glaze is accomplished only after the crowns have been recontoured.have been recontoured. www.indiandentalacademy.comwww.indiandentalacademy.com
  127. 127. • The working cast with restorations isThe working cast with restorations is placed on the surveying table.placed on the surveying table. • A hand piece holder is attached to theA hand piece holder is attached to the vertical arm of the surveyor.vertical arm of the surveyor. • The hand piece will be parallel to theThe hand piece will be parallel to the selected path of insertion and guidingselected path of insertion and guiding planes can be refined by movingplanes can be refined by moving surveying table so that the mountedsurveying table so that the mounted stone contacts the guiding plane of thestone contacts the guiding plane of the crown restoration.crown restoration. • A final check also made with analyzingA final check also made with analyzing rod to determine the height of contourrod to determine the height of contour and retentive undercuts remain asand retentive undercuts remain as plannedplanned www.indiandentalacademy.comwww.indiandentalacademy.com
  128. 128. PLACING INTERNALPLACING INTERNAL ATTACHMENTS AND RESTSATTACHMENTS AND RESTS www.indiandentalacademy.comwww.indiandentalacademy.com
  129. 129. • The surveyor is used to position the intra coronalThe surveyor is used to position the intra coronal retainers or internal attachments, in the wax crownretainers or internal attachments, in the wax crown pattern on abutment teeth as the patterns are beingpattern on abutment teeth as the patterns are being formed.Absolute parallelism among all theformed.Absolute parallelism among all the attachment is essential.attachment is essential. • Internal rests,exaggerated occlusal rest with verticalInternal rests,exaggerated occlusal rest with vertical walls and flat floors,can be created by usingwalls and flat floors,can be created by using surveyor as a form of drill press.surveyor as a form of drill press. • A hand piece is attached to the vertical arm of theA hand piece is attached to the vertical arm of the surveyor by means of hand piece holder.surveyor by means of hand piece holder. www.indiandentalacademy.comwww.indiandentalacademy.com
  130. 130. • The internal rests can beThe internal rests can be machined in the waxmachined in the wax patterns for crowns on thepatterns for crowns on the abutment teeth.abutment teeth. • After the crowns are castAfter the crowns are cast same hand piece and burssame hand piece and burs are used to refine the rests.are used to refine the rests. www.indiandentalacademy.comwww.indiandentalacademy.com
  131. 131. RECENT ADVANCESRECENT ADVANCES www.indiandentalacademy.comwww.indiandentalacademy.com
  132. 132. Electronic surveyingElectronic surveying www.indiandentalacademy.comwww.indiandentalacademy.com
  133. 133. • A 3-dimensional computer model of a conventionalA 3-dimensional computer model of a conventional cast from a patient is obtained using an opticalcast from a patient is obtained using an optical surface capture device (a scanner).surface capture device (a scanner). • The shape of number of components of aThe shape of number of components of a removable partial denture framework was modeledremovable partial denture framework was modeled on the 3-dimensional scan electronically, usingon the 3-dimensional scan electronically, using computer-aided design software.computer-aided design software. • A physical plastic shape of the components wasA physical plastic shape of the components was produced using a Rapid Prototyping machine andproduced using a Rapid Prototyping machine and used as a pattern.used as a pattern. www.indiandentalacademy.comwww.indiandentalacademy.com
  134. 134. • As work progressed, a “barrel” shape was usedAs work progressed, a “barrel” shape was used for development. The program defined thefor development. The program defined the surface area of teeth apical to the survey line bysurface area of teeth apical to the survey line by identifying the downward facing triangles. Theidentifying the downward facing triangles. The upper boundary of this area defined the surveyupper boundary of this area defined the survey line.line. • As in physical dental cast surveying, theAs in physical dental cast surveying, the electronic survey line is affected by theelectronic survey line is affected by the inclination of the cast. A series of rotationalinclination of the cast. A series of rotational transformations allowed survey lines at varioustransformations allowed survey lines at various tilts of the cast to be identified. shows the barreltilts of the cast to be identified. shows the barrel with a tilt of 20 degrees.with a tilt of 20 degrees. www.indiandentalacademy.comwww.indiandentalacademy.com
  135. 135. • The effects when these programs areThe effects when these programs are transferred to larger files of surface models of atransferred to larger files of surface models of a scanned tooth and a cast Techniques to allowscanned tooth and a cast Techniques to allow digital cast surveying before the production ofdigital cast surveying before the production of patterns were also developed.patterns were also developed. • RP [rapid prototyping] processes creates aRP [rapid prototyping] processes creates a pattern of a removable partial denture frameworkpattern of a removable partial denture framework in the typical dental laboratoryin the typical dental laboratory • The results show that digital dental surveyingThe results show that digital dental surveying and machine-produced sacrificial patterns canand machine-produced sacrificial patterns can be accomplished.be accomplished. www.indiandentalacademy.comwww.indiandentalacademy.com
  136. 136. www.indiandentalacademy.comwww.indiandentalacademy.com
  137. 137. www.indiandentalacademy.comwww.indiandentalacademy.com
  138. 138. www.indiandentalacademy.comwww.indiandentalacademy.com
  139. 139. 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-chromiumfitted cobalt-chromium RPD frameworkRPD framework produced by cad-camproduced by cad-cam and rapid prototypeand rapid prototype technology.technology. www.indiandentalacademy.comwww.indiandentalacademy.com
  140. 140. www.indiandentalacademy.comwww.indiandentalacademy.com
  141. 141. www.indiandentalacademy.comwww.indiandentalacademy.com
  142. 142. The   Highriser surveyor  is a pendulum arm Blockout/Survey Instrument for fabricating removable partial dentures. •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 to individual preference •Heating element attachment is designed for easy use and various size tips are available •A convenient attachment holder on the column for www.indiandentalacademy.comwww.indiandentalacademy.com
  143. 143. The  SKYSCRAPER surveyor is a dual pendulum Electronic Blockout/Survey Instrument for fabricating removable partial dentures. ADVANTAGES •The heating element does not have to be removed when surveying; By simply rotating the column the new tool is ready for use www.indiandentalacademy.comwww.indiandentalacademy.com
  144. 144. ConclusionConclusion • When performing oral rehabilitation with removable partialWhen performing oral rehabilitation with removable partial dentures, the objective of the dentist should be to make adentures, the objective of the dentist should be to make a prosthesis that the patient can easily seat and remove fromprosthesis that the patient can easily seat and remove from the mouth and yet, when seated, the prosthesis should resistthe mouth and yet, when seated, the prosthesis should resist the dislodgment potential caused by masticatory function,the dislodgment potential caused by masticatory function, especially mastication of sticky foods.especially mastication of sticky foods. • The problem involves an interaction of engineering andThe problem involves an interaction of engineering and biologic elements, so a biomechanical approach should bebiologic elements, so a biomechanical approach should be used for its solution. On this basis, it is imperative thatused for its solution. On this basis, it is imperative that diagnostic casts for all removable partial dentures should bediagnostic casts for all removable partial dentures should be analyzed with a dental parallelometer (surveyor), theanalyzed with a dental parallelometer (surveyor), the instrument that permits accurate planning of each structuralinstrument that permits accurate planning of each structural detail of the prosthesis.detail of the prosthesis. www.indiandentalacademy.comwww.indiandentalacademy.com
  145. 145. BIBLIOGRAPHYBIBLIOGRAPHY • Text Book of Partial Dentures – Applegate.Text Book of Partial Dentures – Applegate. • Text Book of Partial Dentures –Text Book of Partial Dentures – McCracken.McCracken. • Text Book of Partial Dentures – Osborne &Text Book of Partial Dentures – Osborne & Lamee.Lamee. • Text Book of Partial Dentures – Millers.Text Book of Partial Dentures – Millers. • Text Book of Partial Dentures – A.A.Grant.Text Book of Partial Dentures – A.A.Grant. • Clinical removable partial prosthodontics –Clinical removable partial prosthodontics – Kenneth L. StewartKenneth L. Stewart • Dental laboratory procedures – Rudd &Dental laboratory procedures – Rudd & MorrowMorrow www.indiandentalacademy.comwww.indiandentalacademy.com
  146. 146. 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-Part 1:Robert L. Engelmeir, J.P.D.2002;11;11- 18.18. Part 2: “Part 2: “ J.P.D.2002;11:122-130.J.P.D.2002;11:122-130. Part 3: “Part 3: “ J.P.D.2004;13:195-202.J.P.D.2004;13:195-202.    A technique for fabricating patterns for removableA technique for fabricating patterns for removable partial denture frameworks using digitized castspartial denture frameworks using digitized casts and electronic surveyingand electronic surveying 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 importanceSurveying removable partial dentures: the importance of guiding planes and path of insertion for stabilityof guiding planes and path of insertion for stability The Journal of Prosthetic DentistryThe Journal of Prosthetic Dentistrywww.indiandentalacademy.comwww.indiandentalacademy.com
  147. 147. www.indiandentalacademy.comwww.indiandentalacademy.com

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