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![Survey lines
• This concept was 1st
advanced by
Prothero in 1916 -
Cone theory → basis
for clasp retention.
• Devan [1955]
referred to the
surface occlusal to
the height of contour
as suprabulge, & the
surface inclining
cervically as
infrabulge.](https://image.slidesharecdn.com/surveyor-200315165145/75/Surveyor-35-2048.jpg)
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Surveyor
The document provides information about surveyors, which are dental instruments used to analyze the contours of teeth and surrounding structures when fabricating dental prostheses. It defines key terms like surveyor, surveying, and survey lines. It discusses the history and recent advances of surveyors, including modifications to traditional surveyors and the integration of new technologies like lasers and 3D modeling. The document outlines the main parts and purposes of a surveyor, and describes the steps involved in surveying a diagnostic cast, including tripoding, determining the path of insertion, identifying retentive undercuts and interferences. Factors that influence the path of insertion and techniques like tilting the cast are also examined.
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Surveyor
- 1.
- 2. CONTENTS • INTRODUCTION • DEFINITION •KEY TERMS • HISTORY • RECENT ADVANCES • PARTS OF A SURVEYOR • PURPOSE OF A SURVEYOR • STEPS IN SURVEYING • TRIPODING • PATH OF INSERTION • FACTORS AFFECTING PATH OF INSERTION • SURVEY LINES • BLOCK OUT • RELIEF • MAINTENANCE • REVIEW OF LITERATURE • CONCLUSION • REFERENCES
- 3. Introduction Systematic designing Mechanical principles Biological principles asymmetrical clusters of teeththat usually lack parallelism crowns of these are irregularly convex in shape separated by areas of residual ridge of varied length and breadth. Surveying procedure - an integral part of planning an RPD
- 4. SURVEYOR A paralleling instrumentused in construction of a dental prosthesis to locate and delineate the contours and relative positions of abutment teeth and associated structures - GPT 9 • An instrument used to determine the relative parallelism of two or more surfaces of the teeth or other parts of the cast of a dental arch - McCracken
- 5. SURVEYING An analysis andcomparison of the prominence of intra oral contours associated with the fabrication of a dental prosthesis - GPT 9
- 6. SURVEY LINE A lineproduced on a cast by a surveyor marking the greatest prominence of contour in relation to the planned path of placement of a restoration - GPT 9
- 7. Before the inventionof the dental surveyor, dentists evaluated axial contours and undercuts of teeth by visual survey of dental casts. DR W M RANDALL – 1980 Arbitrary techniques HISTORY
- 8. Parallelometer An apparatus usedfor making one object parallel with another object, as in paralleling attachments and abutments for fixed dental prostheses or precision attachments for removable dental prostheses. • Developed by Dr. Chayes (1906)
- 9. The First DentalSurveyor • Bridge parallelometer-Dr. A. J. Fortunati was the first to demonstrate the advantages of using a mechanical device to map the contours of the abutment teeth.(1918) at dental clinic Boston • Stanton-Hanau Dental surveying apparatus, patented in 1917 (Discontinued)
- 10. Robinson surveyor The PhiladelphiaDental Clinic Club (1918) 1st commercially available dental surveyor Weinstein and Roth 1923
- 11. The current modelof the Ney surveyor was introduced in 1937. Original Wills surveyor (1929) Developed by Noble G. Wills
- 12. • Modification- Willssurveyor (1937) Electronic surveyor Developed at the United States Air Force School of Aviation Medicine at Randolph Air Force Base (1958)
- 13. Neys fixed Retained by friction withina fixed bearing Jelenko When the nut at the top of vertical arm is loosened, horizontal arm may be made to swivel Spring mounted – return to top position when released Horizontal arm Vertical arm
- 14. OPTICAL SURVEYOR • Devisedby Yilmaz in 1975 • Cast is illuminated by a parallel beam of light. This beam of light is set parallel to the marker rod of the surveyor • Shadows are indicated as undercuts • Borders of bright and dark areas indicate the survey line
- 15. MODIFICATIONS OF SURVEYORS •Multiple surveying arms • Micro surveyor
- 16. The Retentoscope -Saddle-Lock Company Blockout Surveyor
- 17. BROKEN ARM SURVEYORS •Addition of a “broken,” or hinged, horizontal arm. • Facilitated surveying and allowed use of a milling machine through the adaptation of a straight hand piece to the surveying arm
- 18. Milling machines • Dentalsurveyors function as milling machines or drill presses. • Developed for precision attachment applications. • Ensures parallelism of guiding planes milled into castings Chayes milling machine Austenal precision milling machine
- 19. RECENT ADVANCES LASERS • Surveyordramatically exposes undercut areas by projecting a beam of laser light • A prototype surveyor- Intra-Tek, Dallas, TX
- 20. 3D COMPUTER AIDEDDESIGN • Electronically survey the cast. • Depth of undercut is determined from the definitive cast. • Programs were written for this technique using mathematic software (MatLab; The Math Works, Inc, Natick, Mass)
- 21. Parts of surveyor Platform •A level platform on which the cast holder is moved • Parallel to bench top Cast holder A cast holder or surveying table Supports the cast to be analyzed
- 22.
- 23. Vertical arm • supports suprastructure ofthe surveyor Horizontal arm parallel to the horizontal platform, and perpendicular to the vertical and surveying arms, which it connects. Surveying arm Drops vertically from the horizontal arm and that is capable of vertical movement. Its lower end has a mandrel capable of holding surveying tools.
- 25. SURVEYING TOOLS • Analyzingrod/paralleling tool/guideline marker • Carbon marker with metal reinforcement sheath • Undercut gauges • Block out tools Tapered (2 /6 degree taper ) when parallelism is desired Ney wax trimmer for paralleling block out Surveying blade
- 26. ANALYSING ROD CARBONMARKER • This tool contacts the convex surface to be studied in a tangential manner • Relative parallelism of one surface to another determined used to scribe the survey line and to delineate an undercut area of the soft tissue or ridge
- 27. UNDERCUT GUAGES used toidentify the specific amount and location of desired retentive undercut on the surface of the abutment tooth
- 28. • Amount ofundercut is measured in hundredths of an inch • 0.01 → cast retainers – most desirable location • 0.02 → wrought wire retention • 0.03 → rarely used
- 29. BLOCK OUT TOOLS/ WAX KNIFE • This instrument is used in late stages of removable partial denture construction to eliminate or block out areas of undesirable undercuts with wax on the cast before the framework is made NEY SURVEYOR BLADE
- 30. • Tapered (2/6 degree taper ) when parallelism required- parallel block out • Block out extends from survey line to gingiva
- 31.
- 32. PURPOSE OF ASURVEYOR • SURVEYING THE DIAGNOSTIC CAST • RECONTOURING ABUTMENT TEETH ON DIAGNOSTIC CAST • CONTOURING WAX PATTERNS • MEASURING A SPECIFIC DEPTH OF UNDERCUT • SURVEYING CERAMIC VENEER CROWNS • PLACING INTRACORONAL RETAINERS • PLACING INTERNAL RESTS • MACHINING CAST RESTORATIONS • SURVEYING AND BLOCKING OUT THE MASTER CAST
- 33. SURVEYING THE DIAGNOSTICCAST • To determine the most desirable path of placement that will eliminate or minimize interference to placement and removal. • To identify proximal tooth surfaces that need to be made parallel as that they act as guiding planes during placement and removal. • To locate and measure areas of teeth that may be used for retention. • To determine whether tooth and bony areas of interference will need to be eliminated surgically or by selecting a different path of placement.
- 34. • To determinethe most suitable path of placement that will permit locating retainers and artificial teeth to the best aesthetic advantage. • To permit an accurate charting of the mouth preparations to be made. • To delineate the height of contour on abutment teeth and to locate areas of undesirable undercuts that are to be avoided, eliminated or blocked out. • To record the cast position in relation to the selected path of placement for future references
- 35. Survey lines • Thisconcept was 1st advanced by Prothero in 1916 - Cone theory → basis for clasp retention. • Devan [1955] referred to the surface occlusal to the height of contour as suprabulge, & the surface inclining cervically as infrabulge.
- 36. • BLATTERFEIN’S CLASSIFICATION Medium survey line Diagonal survey line High survey line Low survey line
- 37. Colour coding • Browncrayon pencil - out line the metallic portion. • Blue crayon pencil - out line the acrylic portion of the denture base. • Red crayon pencil - to indicate areas on the teeth that will be prepared,recontoured or relieved./required action . • Placement of tripod marks • Surfaces that must be recountoured are outlined red and filled with evenly spaced diagonal lines • Soft tissue areas that require relief are outlined in red accompanied by word relief • Solid red - rests and rest seats. • Black pencil and carbon marker - used to denote the survey lines and enter information on the base of the cast-tooth replacement,type of clasp,depth of undercut
- 38. Survey process Locating andmarking measured undercuts Placing survey lines Tripoding the cast Path of insertion Identifying most favourable tilt Retentive undercuts Esthetics Guiding planes Interferences
- 39. Orientation of thecast Cast tilting Visual analysis using analyzing rod Decide on the tilt and mark the survey lines /soft tissue undercuts using carbon markers Undercut gauges used to measure amount of retention Path of placement and removal Factors influencing path of insertion Guiding planes Tripoding of casts Surveying- step by step procedures
- 40. Orientation of thecast • Casts oriented such that the anterior part is always toward the vertical member of surveyor and away from the operator All casts are considered as lower casts in standard position
- 41. Method for manipulationof surveyor • braced on horizontal arm of surveyor to raise and lower vertical shaft in spindle. • Also to tighten and loosen the tilt top once in position Right hand • adjusting the tilt topLeft hand
- 42. Preliminary visual assessmentof the study cast Cast tilting changing the position of the cast, which thus changes the long axis of each tooth relative to the horizontal plane
- 43. Why tilting isdone? • Obtain the most advantageous path of insertion • Establish a more desirable undercut on other teeth involved in the design. • Distribute available undercuts to produce more uniform retention throughout the available teeth • Tilting may be used to increase desirable undercuts and to decrease undesirable undercuts. • Through tilting, it is possible to increase the undercuts on one side of the tooth while decreasing them on the other side of the tooth
- 44. BASIC TILTS • Thebasic position or tilt of the cast on the surveyor should be the horizontal tilt or zero degree tilt. • Occlusal surfaces of the teeth are at or nearly parallel to the horizontal plane. • Standard reference position from which further tilts originate Horizontal tilt or zero degree tilt.
- 45.
- 49. PATH OF INSERTION Thespecific direction in which a prosthesis is placed on the abutment teeth or dental implant(s) - GPT 9 • STRAIGHT DOWNMANDIBLE • STRAIGHT UP MAXILLA Parallel to the vertical arm of the surveyor Determined by the tilt of the cast on the surveying table Indicated by vertical spindle of surveyor in relation to occlusal plane of cast or tilt
- 50. • BOUNDED BYTEETH AT ONLY ONE SIDE • MULTIPLE PATH OF INSERTION CLASS I ARCHES AND CLASS II WITHOUT MODIFICATION • MODIFICATION SPACE WILL DETERMINE PATH OF INSERTION • IF GUIDING PLANE PREPARED – SINGLE PATH OF INSERTIONCLASS II MODIFICATION • ENTIRELY TOOTH BOUNDED • GUIDING PLANES ON PROXIMAL SURFACES- SINGLE PATH OF INSERTIONCLASS III • PARALLEL TO GUIDING PLANES ON ABUTMENT TEETH ADJACENT TO THE EDENTULOUS SPACE • SINGLE PATH OF INSERTION CLASS IV
- 51. SINGLE PATH OFINSERTION 1. equalizes retention on all abutments 2. provides bracing and cross-arch stabilization of teeth 3. minimizes torquing forces of the partial denture 4. allows the partial denture to be removed without encountering interferences 5. directs forces along the long axes of the teeth 6. provides frictional retention from contact of parallel surfaces on the teeth ADVANTAGES
- 52. • In orderto provide a single path of insertion for a partial denture, some axial surfaces of abutments must be prepared so that they parallel the path of insertion. These parallel surfaces are called guiding planes
- 53. Factors affecting pathof insertion Design of the prosthesis Esthetics Guiding planes Interferences Retentive undercuts
- 54. RETENTIVE UNDERCUTS • Surveyingprocedure is always started with the cast to be analyzed positioned in the cast holder so that the occlusal surfaces are in a horizontal plane and examined for presence of retentive undercuts • Ideal undercut for an abutment is 0.01 inch • In all cases undercuts should be located in the apical third of clinical crown Distobuccal line angle Mesiobuccal line angle Gingival third of clinical crown Midfacial surface Depanding upon practioners clasping philosophy
- 55. Dislodging forces Pull producedby sticky food Force of gravity acting on maxillary denture Directed perpendicular to occlusal plane Retentive undercuts must be present on abutment teeth when cast displays a horizontal tilt If retentive undercuts are not present-must be created in mouth
- 56. Retentive undercuts Change pathof placement to increase or decrease angle of convergence of opposing retentive surfaces of abutment teeth Carefully recontour enamel surfaces Place fixed restorations (gold crowns or metal ceramic crowns, class v inlays, ceramic veneers) Alter flexibility of clasp arms by changing the design Tilt is changed so that retentive clasp will be positioned no farther occlusally or incisally than the junction of the gingival and middle thirds of the teeth More estheticDecrease torqueing forces to abutment teeth
- 57. Interferences • Certain structuresin the oralcavity • May interfere with insertion of RPD TEETH BONY PROMNENCES SOFT TISSUE UNDERCUTS EXOSTOSES SURGICAL INTERVENTION CHANGING THE TILT OF THE CAST MINIMISE SURGICAL PROCEDURES NEVER COMPROMISE RESTORATIVE OUTCOMES
- 58. MAXILLA PALATAL TORUS ALTER MAJOR CONNECTOR DESIGN SURGICAL REMOVAL BUCCALEXOSTOSES AND UNDERCUTS INCREASED ACCUMULATION OF FOOD DECREASED DENTURE STABILITY FACIAL TIPPING OF POSTERIOR TEETH HEIGHT OF CONTOUR MOVES TOWARDS OCCLUSAL SURFACE GINGIVAL TISSUES IN UNDERCUT
- 59. MANDIBLE MANDIBULAR TORI LINGUAL TIPPING OFPOSTERIOR TEETH NO UNDERCUT ON FACIAL SURFACE AREAS ADJACENT TO PEAR SHAPED PADS BONY PROMINENCES FACIAL SURFACES OF MANDIBULAR CANINES AND PREMOLARS MAY PRODUCE SOFT TISSUE UNDERCUTS Alter major connector design Reccountouring of teeth Orthodontic correction Tilting the cast
- 60. AESTHETICS • Metal, usuallyin the form of clasp arms, must be concealed as much as possible without compromising the necessary support and stability of the prosthesis • Anterior artificial teeth should be placed in the most natural position • Avoid unnecessary display of metal • The ideal position of retentive clasps is in gingival third of the clinical crown • Prosthetic teeth must be selected appropriately contoured and positioned
- 61. Guiding planes • Twoor more parallel axial surfaces on abutment teeth which can be used to limit the path of insertion and improve the stability of a removable prosthesis. • Surveyor locates the existing or potential surfaces of teeth which can be converted to guiding planes by selective grinding formed on the proximal or axial surfaces of teeth. Contacted by minor connector or rigid elements of the partial denture
- 62. Guiding planes Always parallelto planned path of insertion Rarely greater than 2mm to 4mm in height Stabilize prosthesis against lateral forces Protect weakend teeth from destructive lateral forces Prepared most on enamel surfaces also on cast restorations while doing wax patterns Ensures predictable clasp assembly function.
- 63. Tripoding • After finaltilt of cast has been selected , it must be recorded so that the cast may be later repositioned precisely. This procedure is referred to as tripoding. Why is tripoding done ? • Returning to surveyor for future references especially during mouth preparation • Returning working casts for shaping wax patterns, trimming block out on the master casts ,locating clasp arms in relation to undercut areas
- 64. METHOD 1 • 3cross marks (each line 3mm wide) / dots on the tissue portion of the cast, lingual to the remaining teeth ,at widely separated points with vertical arm of the surveyor are maintained at fixed position • analyzing rod should be fixed • Dots /cross marks are encircled with a colored pencil for easy identification • Resultant lines should be about 4mm long an relatively narrow
- 65.
- 66. SURVEYING THE MASTERCAST • Surveyed as a new cast • Prepared proximal guiding plane surfaces will indicate the correct anterioposterior tilt • Any remaining interferences after mouth preparation must be eliminated with block out • Tripoding done • Survey lines marked
- 67. BLOCK OUT Any undercutareas crossed by rigid part of denture during seating and removal Eliminated by block out Block out for convenience Ledges on which clasp patterns are to be placed Relief beneath conncetors to avoid tissue impingement Relief to provide attachment of the denture base to framework
- 68. MATERIALS USED FORBLOCK OUT AND RELIEF Hard baseplate wax Oil based clay Adhesive wax
- 69. Thickness Only undercut remaining below contactof surveyor blade with tooth surface/surface of cast PARALLEL BLOCK OUT Proximal tooth surfaces to be used as guiding planes beneath all minor connectors tissue undercuts to be crossed by rigid connectors tissue undercuts to be crossed by origin of bar clasps Beneath barclasp arms to gingival crevice deep interproximal spaces to be covered by minor connectors or linguoplates
- 70. Ledges for locationof On buccal and lingual surfaces to locate wax patterns for clasp arms With hard baseplate wax Reciprocal clasp arms To follow height or convexity Retentive clasp arms As cervical as tooth contour permits Point of origin of clasp to be incisal or occlusal to height of convexitty To include undercut area in keeping with flexibility of clasp used SHAPED BLOCK OUT
- 71. ARBITRARY BLOCK OUT •Enough just to eliminate gingival creviceAll gingival crevices • Leveled arbitrarily with wax spatula Gross tissue undercuts situated below areas involved in the design of denture framework • Smoothed arbitrarily with a wax spatulaTissue undercuts distal to cast framework • Filled and tapered with spatula to within upper third of crown Labial and buccal tooth and tissue undercuts not involved in denture design
- 72. RELIEF • 32 gaugewax – if slope of lingual alveolar ridge is parallel to path of placement • 32 gauge wax – after parallel block of undercut if slope of lingiual alveolar ridge is undercut to the path of placement Beneath lingual bar connectors/bar portion of lingual plates • Thin layer flowed on with hot wax spatula • If maxillary torus s covered; thickness depands on difference in degree of displacement of tissues Areas in which major connectors will contact thin tissue, such as hard areas so frequently found on lingual or mandibular ridges and elevated palatal raphes • 20 gauge waxBeneath framework extensions on to ridge areas for attachment of resin bases
- 73. CONTOURING WAX PATTERNS •Surveyor blade – used as wax carver • It maintains the proposed path of placement maintained through out preparation of cast restorations for abutment teeth • Surfaces of restorations that provide reciprocation for clasp arms should be contoured to permit their location well below occlusal surfaces and on non retentive areas • Those areas that provide retention for clasp arms should be contoured such the clasps are placed in the cervical third of the crown
- 74. SURVEYING CERAMIC VENEERCROWNS • Used to contour all areas of wax pattern for veneer crown (used to restore abutment teeth on which extra coronal direct retainers are placed) except the buccal or labial surface • Correct contour to be ensured before glazing
- 75. PLACEMENT OF INTERNALREST SEATS • The surveyor maybe used as a drill press, with a dental headpiece attached to the vertical arm by a headpiece holder. • Carved in wax patterns and refined further with handpiece after casting.
- 76. PLACEMENT OF INTRACORONALRETAINERS • To select a path of placement in relation to the long axes of abutment teeth that will avoid areas of interference elsewhere in the arch • To cut recesses on the diagnostic casts for estimating proximity of recess to the pulp(used in conjunction radiographic information to estimate pulp size and location) • To carve recesses in wax patterns or in castings – keyway portion (using handpiece holder) • Ensures placement of each keyway parallel to other keyways else where in the arch.
- 77. MACHINING CAST RESTORATIONS •With a hand piece holder attached ,the refining of axial surfaces can be done with a suitable cylindrical carborundum point. • Proximal surfaces of crowns and inlays to serve as guiding planes.
- 78. Maintenance • Wipe thebase of surveying table and surveying platform with alcohol or acetone soaked gauze pad. • Acrylic resin powder can be sprayed for smooth gliding. • Machine oil should be applied to vertical arm before and after use, each time.
- 79.
- 80. Electronic surveying ofdigital partially dentate casts Zhonghua Kou Qiang Yi Xue Za Zhi. 2009 Dec;44(12):763-6 OBJECTIVE: To develop a method of surveying the digitalized partially dentate cast in order to accomplish computer aided design (CAD) of removable partial denture (RPD) frameworks. Survey lines of digitalized partially dentate casts were generated in computer. The undercut area and its depth were identified and the undercut could be blocked out. The shape of survey lines on the digitalized casts was similar to that on the physical casts drawn using traditional method.
- 81. Guiding planes inclasp reciprocation William Stent JPD 1969;34:408-414 According to this article- • 2 factors that improve the retention and reciprocation in clasp design are: • Length of guide plane ,coronogingivally – this will adequately reciprocate the action of retentive arm • Relation of undercut to the guide plane
- 82. • With thedegree of undercut the contour of the tooth influence the length of guiding plane. • Optimum guide plane length to have retention and to protect free gingival margin is abt 5mm
- 83. The importance ofguiding planes for stability O. L. Bezzon,G. C. Mattos J Prosthet Dent 2002;83:412-18 • The flat axial surfaces in an occlusal-gingival direction on abutments are referred to as guiding planes. • They should be prepared to be parallel to one another and to the path of insertion. • During insertion, the rigid parts of the prosthesis contact with these surfaces, which direct the movement of the RPD until it is seated securely in the predetermined terminal position in the mouth.
- 84. Accuracy of adigital removable partial denture fabricated by casting a rapid prototyped pattern: A clinical study Lee et.al J Prosthet Dent 2017 • The purpose of this clinical study was to analyze the accuracy of digital RPDs by using the replica technique. • The fit accuracy of digital RPDs fabricated using electronic surveying was analyzed by fabricating replicas with silicone registration material and measuring with a stereomicroscope. A total of 348 measurements in 10 participants were analyzed. • The internal discrepancy of the metal framework was evaluated among participants using different Kennedy classifications.
- 86. Conclusions • Surveying isan important and indispensable step in designing a cast partial denture. • Continued ergonomic refinement of the surveyor should ensure its continued use during the treatment planning process. • Intelligent use of the procedure will allow us to render superior service to the patient.
- 87. References • Mc Cracken’s– Removable Partial Prosthodontics • Strewart – Removable Partial Dentures • Johnson – Removable Partial Prosthodontics • Wagner A.G. A study of four methods of recording the path of insertion of removable partial dentures J. Prosthet Dent.1976; 35:267-272. • Yilmaz. G Optical surveying of casts for removable partial dentures J. Prosthet Dent.1975; 34:292-296 • K.D.Rudd,R.M.Morrow,J.E.Rhoads;Dental laboratory procedures-removable partial denture vol.3.2nd edition. • Ansari. I.H. A procedure for reorienting a cast on surveyor . J.P.D 1994 : 72: 104-107. • Stern W.J. Guiding planes in clasp reciprocation and retention. JPD 1975; 36:4:408-414. • Engelmeier R.L. The history and development of the Dental Surveyor JPD, 2002, 11: 1:11 – 18. • Beezon O.L. et al, Surveying removable partial dentures, the importance of guiding planners & path of incertion for stability JPD 1997 : 78: 4: 412 – 418.
- 88.
Editor's Notes
- #4 A typical dental arch, for which a partial denture is to be planned In order to deliver a successful prosthesis, logically design, select and position the parts of an RPD to control potential movement under functional load. This will enable the supporting of teeth and soft tissues to withstand the forces that will be created by the movement Planning of an RPD with the use of a dental surveyor helps in analysis and accomplish tooth modifications and placement of retentive components in correct positions that is critical for optimum stability and retention are necessary for success of the prosthesis.
- #8 sharp pencil is held perpendicular to the occlusal plane a pencil lead is passed over the axial surfaces of the teeth to develop a survey line Accuracy → Dependent on the operator’s ability to keep the pencils parallel and steady. INTRA ORAL FITTING PROCESS TIME CONSUMING POORLY FITTING PROSTHESIS
- #9 Consisted of 2 mandrels that remained parallel no matter how far apart they were placed Could also be used to identify non-parallel and undercut surfaces of prepared teeth
- #10 He replaced the steel analyzing rod of a “Parallelometer” with a graphite rod and traced survey lines Changed rpd service from guesswork to an objective, scientifically based procedure
- #11 1923 Jm ney corporation introduced Most widely used are ney and jelenko surveyors
- #12 Fixed horizontal arm and spring loaded vertical arm for neys fan shaped undercut gauge triangular carbon marker Rotating horizontal arm , and a spring loaded surveying arm for wills Cast was held by wax
- #13 Spring loaded surveying arm The surveyors marketed by Ney Dental International and J. F. Jelenko and Company (Armonk, NY) dominates the market. Powered by dry cell batteries and was capable of passing a weak current through the surveying tool to the cast surface. Casts were treated with phenolphthalein, and contact with the surveying tool produced a fine, red survey line.
- #14 Principal parts of jelenko surveyors are the same as that of neys To some its confusing to coordinate 2 horizontal movement nut tight use horizontal arm in fixed position Dr Noble Wills incoorpotated this feature to permit freedom of movement of the arm in horizontal plane rather than to depand entirely on horizontal movement of the cast Vertical arm of neys
- #16 Saves time when changing surveying tools. Hand held surveyor, Collapses for handy storage
- #17 A work light is attached to the vertical arm. Pendulum block out surveyor
- #18 Ney surveyor converted into a broken-arm surveyor. The Torit broken-arm dental surveyor
- #20 A beam of laser light projects vertically downward from the distal end of the horizontal arm to serve as the surveying arm. No visible “survey line” at the height of contour of the teeth The laser light is visible only above the height of the contour, whereas the undercut below the height of the contour is cast in a dark shadow
- #21 Computer aided surveying using cad cam technology In the ensuing years a number of dental surveyors were introduced, but all were intended to facilitate the design process and improve treatment outcomes
- #22 Currently there are a limited number of surveyors on the market.these vary in design,but most have following parts
- #23 It includes a clamp to hold the cast firmly in place and is mounted on a ball-and-socket joint between the table and base that permits the cast to be oriented in various horizontal planes during surveying
- #25 NEY SURVEYOR
- #27 5H drawing pencils used Metal reinforcement sheath
- #29 CAST GOLD ALLOYS add type of clasps used In all cases apical third of the clinical crown
- #30 Shaped block out – wax is trimmed flush with the survey line
- #32 Used for parallel block out
- #37 He introduced the term Near zone & Far zone to divide the buccal & lingual surfaces into 2 halves. Near zone- that ½ that lies near nearer to the saddle
- #40 Steps by step procedures in surveying a diagnostic cast
- #41 Position for description is from behind the cast or from the position of the tongue
- #45 Tilt of the cast is described from the view point of a person looking at its posterior surface
- #46 If posterior is lowered cast is said to have a posterior tilt If anterior of cast is lowered
- #49 Left side is lowered Amount of maximum and minimum tilting
- #50 A path of insertion (or removal) is the path along which a prosthesis is placed (or removed)intraorally. A removable partial denture is usually fabricated to have a single path of insertion or removal from the mouth
- #51 For tooth bound edentulous area with guiding plane created on all abutment teeth Cl 2 with mod 1(tooth abutment) because the path of distal extension side will be controlled by rigid major connector and must follow path of tooth bounded side
- #54 Additionally if implant is part of the design its long axis is considered in relation to the path or placement or removal
- #55 Retentive areas must exist for a given path of placement and must be contacted by retentive clasp arms that are forced to flex over a convex surface during placement and removal Satisfactory clasp retention is no more than resistance to clasp deformation Minimum acceptable retention
- #63 Guiding planes are necessary to give positive direction to movement of the restoration to and from its terminal position, forcing the retentive arm to flex making the clasp retentive
- #65 Not marked on the areas of the cast involved in framework design On returning the cast to the surveyor, it should be tilted until the tip of surveyor blade or stylus contacts the three dots in the same plane
- #66 Score 3 sides of the base of the cast with a sharp instrument/marking pencil held against the surveyor blade Tilting the cast until all 3 lines are parallel to surveyor blade, restores the original tilt
- #67 Follows mouth preparations,path of placement,location of retentive areas,interferences Gross interferences will be eliminated in mouth prep Pin cemented in the center of the cast • Use of protractor fixed on surveyor • Use of dental bur in place of pin • Use of position recorder device on a surveyor • Smooth or threaded pin with sleeve • Use of inclinometer • Key and keyway system • Tripoder attachment
- #68 Rigid except retentive terminal of clasp Areas crossed by rigid parts of denture during seating and removal Areas not involved blocked for convenience Ledges on which clasp patterns are to be placed Relief beneath connectors Relief to provide for attachment of denture base to the framework
- #71 So that – placed as cervical as possible without becoming retentive
- #74 Guide planes on all proximal surfaces of wax patterns adjacent to the edentulous areas should be made parallel to the previously determined path of insertion
- #75 Pricipal goal to develop esthetic replica Areas to be recontoured or reshaped has to be done and glazing is done only after recontouring
- #76 An internal rest seat differs from internal attachment in that some portion of the prosthesis framework is waxed and cast to fit into the rest seat rather than a matched key and keyway attachment
- #77 INTERNAL ATTACHMENTS In the placement of intracoronal retainers the surveyor is used as follows
- #78 Machined parallelism justifies the additional step to accomVertical surfaces above crown ledges will be improved by machining plish it
- #81 The new module in Tanglong software was developed specifically for surveying partially dentate casts. It had a user-friendly interface with the easy-to-understand menus.
- #86 Digital RPDs fabricated using electronic surveying varied in accuracy of fit and showed acceptable clinical accuracy.
- #87 Type of surveyor used in our dept