1. Today AM – Need Ney Surveyor PM - Clinic
Get Casts, Typodonts & Marking Sheets at front
Presentations and Videos
Survey Class I & II Casts (‘TYPO’)(w/o preps)
Tripod Casts
Get Mannikin Heads & Mounts ready for PM
PM - Clinic
Prepare guiding planes on Class I & II Typodonts (last sheet Course Sched)
Formative
Marking sheets

2. Surveying, Path of Insertion, Guiding Planes

3. Definitions
Height of contour
Suprabulge
Undercut = Infrabulge

4. Definitions
Height of contour
Undercut = Infrabulge
Suprabulge

5. Rule: Retentive tip should usually be designed to be placed in the gingival 1/3

6. Path of Insertion Path that the prosthesis is Placed/removed
Usually a single path

7. Advantages of a Single Path of Insertion
Equalizes retention

8. Advantages of a Single Path of Insertion
Bracing and Cross-arch Stabilization

9. Advantages of a Single Path of Insertion
Minimizes torque on abutments

10. Advantages of a Single Path of Insertion
Allows removal without encountering interferences

11. Advantages of a Single Path of Insertion
Directs forces along long axes of teeth

12. Advantages of a Single Path of Insertion
Provides frictional retention

13. Selecting a Single Path of Insertion
Use a dental surveyor to
Select path
Prepare guiding planes

14. Parts of a Surveyor Surveying
Movies:
Parts of a Surveyor Surveying

15. Guiding Plane Preparation
Where rigid components contact abutments
Proximal Plates
Bracing Arms
Rigid portions of Retentive Arms

16. Other Uses of a Surveyor
Blocking out undesirable undercuts
Ensures the framework is not cast in an undercut

17. Selecting a Path of Insertion
Orient cast relatively horizontal
Final tilt rarely more than 10° from horizontal

18. Selecting a Path of Insertion
Place analyzing rod against abutments
Contact point is Height of Contour
Below is infrabulge
Above is suprabulge

19. Selecting a Path of Insertion
Tilt cast to obtain maximum parallelism
Heights of contour are at relatively same position occluso-gingivally
Equal amounts of undercut

20. Altering Path of Insertion
Proximal surfaces similar undercuts
Retentive areas similar undercuts

21. Selecting a Path of Insertion
Modify tilt if necessary
Soft tissue interferences

22. Selecting a Path of Insertion
Modify tilt if necessary
Esthetics

23. Once Path Selected Instructor: Approves path Demo:
Mark heights of contour with carbon marker
Tripod

24. Selecting a Path of Insertion
Lock cast position & tripod

25. Tripoding

26. Optimal Path of Insertion
Retentive undercuts equalized
Retentive arm has a different path of escapement than guiding plane, so it must flex during removal

27. Optimal Path of Insertion
Retentive undercuts equalized
Ideally, retentive arms should oppose each other on opposite sides of the arch

28. Optimal Path of Insertion
Minimize severe tooth & soft tissue interferences

29. Optimal Path of Insertion
Esthetics
Minimize display of clasps, metal components

30. Optimal Path of Insertion
Prepare Guiding Planes
Flat surfaces parallel to path of insertion
Control & limit movement of RPD
Initial contacts for RPD

31. Guiding Planes
Stabilization

32. Effectiveness of Guideplanes
Most effective when:
Parallel to each other
More than one common axial surface

33. Effectiveness of Guideplanes
Most effective when:
Directly opposing each other

34. Effectiveness of Guideplanes
Most effective when:
Prepared on several teeth
Cover a large surface area

35. Preparing Guiding Planes Assessing Guide Planes
Movies:
Preparing Guiding Planes
Assessing Guide Planes

36. Assessing Guiding Planes
Proximal View
Carbon Markings
Facial View

37. Preparing Guiding Planes
Select path of insertion
Design Partial Denture *
Select number & position of guiding planes
Prepare guiding planes

38. Use Surveyor to Align Bur Intraorally
When Preparing Guide Planes Cast should be on Surveyor Close to Operator to Compare Orientation of Analyzing Rod and Bur to the Tooth

39. FINGER REST!

40. Burs
8837K-014
Long Cylindrical Carbide or Diamond (8837K 014)

41. Guiding Plane Dimensions

42. Axial Surface Already Parallel to Path of Insertion
NO Preparation !

43. Polish Prepared Surfaces
Rubber wheels or points

44. Prepare Guiding Planes First

45. Effects of Guiding Planes On Retention & Stability
Maintains Retention

46. Effects of Guiding Planes On Retention & Stability
Minimizes Need for Retention

47. Effects of Guiding Planes On Retention & Stability
Stabilizing Teeth

48. Marking Sheets

49. Other Alterations of Axial Contours
Lowering Heights of Contour
Rigid elements contacting abutments
Improve esthetics
Prepare guiding planes - most efficient method to lower

50. Other Alterations of Axial Contours
Raising Heights of Contour
Insufficient retention in gingival 1/3 (at least 1mm from gingiva)
Prepare undercut
Add resin above to create undercut

51. Preparing Retention
Axial surface must be close to parallel the path of insertion

52. Retentive Preparation Shape
Follows the path of designed retentive tip

53. Creating Undercuts with Bonded Resins
Axial surface must be close to parallel the path of insertion

54. Summary of Abutment Modifications
After RPD Designed
Guideplanes
Lower heights of contour to eliminate interferences & improve esthetics
Create undercuts if absolutely necessary (raising heights of contour)
Rest seat preparation