3. INDIRECT RETAINERS

4. Definitions
Indications for I. R.
Types
Factors Affecting I.R.

5. Tipping (Rocking)
Is the Rotation of Partial Denture around a Fulcrum

6. F

8. DEFINITIONS

9. Tooth-tissue supported partial dentures are subjected to vertical displacing forces acting in an occlusal direction. These forces may totally displace the denture if the direct retainers are not functioning adequately. However if the direct retainers are adequate, rotation of the denture around a fulcrum axis rather than total displacement occurs. This rotation is counteracted by the unit of the partial denture called "Indirect retainer".

10. In tooth supported partial dentures; tissue away movement of the prosthesis is prevented by the action of direct retainers and rests placed on the abutment teeth (self indirect retainer).
In mucosa supported partial dentures;(full palatal coverage) tissue away movement of the prosthesis is prevented by mechanical means (clasps) and by the action of physical means of retention on a well fitting denture base and the connector (direct indirect retention).

11. Indirect Retainers are “components of removable partial denture that are used to reduces the tendency of the denture to rotate in an occlusal direction about the fulcrum axis”

12. Fulcrum Lines
Retentive fulcrum line is the line joining the retentive tips of the clasps holding the principal abutments (Diagonally placed).
Supportive Fulcrum Line Is the Line Joining the Occlusal Rests Supported by Principal Abutments.

15. F

16. F
This Movement Is Related To Quality Of The Tissue, Extent Of Denture Base And Its Fit And The Amount Of Force Applied

17. Indirect Retention
Components of RPD That Are Used to Reduces Its Tendency to Rotate in an Occlusal Direction About the Fulcrum Axis
Supportive Elements (Rests) Used to Retain Far Ends of Partial Dentures

18. DIRECT RETAINERS
Retaining Elements (Clasps) Used to Retain Near Ends of Partial Dentures

19. F
This Movement Is Related To Quality Of The Tissue, Extent Of Denture Base And Its Fit And The Amount Of Force Applied Support

20. Indications for Indirect Retainers

21. Tooth-tissue Supported Partial Dentures Are Subjected to Vertical Displacing Forces Acting in an Occlusal Direction. If the Direct Ret. Are Adequate, Rotation of the Denture Around a Fulcrum Axis Rather Than Total Displacement Occurs

22. F

23. Class I

24. Class II

25. Class IV

26. Long Span Class III

27. Factors Influencing the Effectiveness of Ind.Ret.
1-Effectiveness of the Direct R.

28. 2- Proper Location of I.R
Well-supported I. R. Should Be Placed As Far From the Fulcrum Line As Possible. The Greater the Distance, the More Effective Is the Indirect Retention
A Perpendicular Line Projecting Anteriorly From the Fulcrum Axis Is the Most Effective Location of I. R. And Affords the Best Resistance Against Vertical Dislodging Forces

33. 3- Effectiveness of the Supporting Structures
Definite, Properly Prepared Rest Seat
Should Never Be Placed on Weak Teeth or on Inclined Surfaces

35. I.R. In the Form of Rest Should Be Placed in a Definite, Properly Prepared Rest Seat That Allows Transmission of the Forces Along the Long Axis of the Tooth Without Slippage of the Rest or Movement of the Tooth

37. 4- Rigidity of the Denture Frame
The Minor Connector Joining the I. R. to the Framework Should Be Rigid. Flexing of the Connector Multiplies Rather Than Dissipates the Applied Forces

39. Factors Influencing the Effectiveness of Ind.Ret.
1- Effectiveness of the D. R.
2- Proper Location of I.R
3- Effectiveness of the Supporting Structures
4- Rigidity of the Denture Frame

40. Talk slowly but think quickly

41. Forms of I.R.
1-Rests
2-Connectors

42. A- R. Used In Mandibular P. D.
Forms of Ind.Retainers
A- R. Used In Mandibular P. D.
1-Auxiliary Occlusal or Canine Rests

44. 2- Principal Occlusal Rest of Modification Area

45. 2- Principal Occlusal Rest of Modification Area1

46. 3- Embrasure Hooks

47. 4- Auxiliary Rests at the Terminal Ends of Ling. Plate or Kennedy Bar

48. A- R. Used In Mandibular P. D.
Forms of Ind.Retainers
A- R. Used In Mandibular P. D.
1-Auxiliary Occlusal or Canine Rests
2- Principal Occlusal Rest of Modification Area
3- Embrasure Hooks
4- Auxiliary Rests at the Terminal Ends of Ling Plate or Kennedy Bar

49. B- Indirect Retainers Used in Maxillary Partial Dentures
1) Cummer Arm
2) Palatal Arm
3) Anterior Palatal Bar
4) Posterior Palatal Bar

50. 5) Palatal Strap and Rugae Support
6) Direct-indirect Retainer (Full Palatal Coverage)
7) Auxiliary Occlusal or Canine Rests
8) Principal Occlusal Rest of Modification Area

51. 1) Cummer Arm

52. 2) Palatal Arm

53. 3) Anterior Palatal Bar

54. 4) Posterior Palatal Bar

55. 5) Palatal Strap and Rugae Support

56. 6) Direct-indirect Retainer (Full Palatal Coverage)

58. Auxiliary Occlusal or Canine Rests

59. Smile when picking up phone. The caller will hear it in youthe r voice

60. THANK YOU