pontics retainers & connectors in FPD.pptx

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1. Pontics, Retainers and Connectors in Fixed Prosthodontics

2. Contents

3. Parts of a fixed partial denture Retainers Pontics Connectors

4. Retainers Definition Types of retainers Selection criteria Design criteria Errors

5. Definitions Retainer – “Any type of device used for stabilization or retention of a prosthesis”- GPT Retainer in FPD – “the part of a fixed partial denture which unites the abutment [s] to the remainder of the restoration- GPT “ Retainers are extra coronal restorations that are cemented to the prepared abutment teeth”- shilling berg The restorations that are cemented to the abutments and retain the FPD in place are called retainers- Tyllman

6. IDEAL RETAINER  One that requires the least amount of destruction to the abutment. One that least destroys the outline form of the tooth Least amount of marginal line Finished about its periphery with great accuracy

7. Types Based on coverage Based on material being used Based on no of retainers

8. Based on coverage A Major Retainers Minor Retainers B Full Veneer Crowns Partial Veneer Crown Conservative [Minimal Preparation] retainers

9. Based on the material being used All metal retainers Metal ceramic All ceramic All acrylic Resin bonded retainers[ FRC,ADORA, …]

10. Based on number of retainers Single Multiple

11. Major retainers Retainers which covers the entire occluding surface of tooth eg full veneer, partial veneer crowns. Minor retainers are small metallic extensions that are cemented to the tooth eg inlay , onlay

12. Full veneer crown Most retentive of all the retainer Extremely short or extensively decayed teeth Gingival decay is prevalent. Marginal gingival health

13. Full Coverage Abutment Retainers. They Afford Greater retention & adequate resistance Higher strength Option to modify occlusal & axial surfaces Indications More than one pontic /long edentulous span Tooth mal positioned /mal aligned Abnormal tooth morphology Tooth to be splinted Improper tooth position To modify the occlusion /occlusal plane Endo treated teeth Need for maximum retention and strength Recontouring axial surfaces To provide contours to receive RPD Existing restorations Extensive destruction from caries /trauma

14. Partial veneer crown are ideal Guides for coronal contours Embrasure forms are pre-established. Adequate amounts of attached gingival Adequate vestibular depth

15. Partial veneer crown may be a Inlay, onlays veneers ¾ crown Reverse ¾ crown Pin-ledge crown Half-crown or mesial version of veneer crown 7/8 crown Adhesive bridges

16. Pin –ledge crown Dowels are cast instead of using metal wire. Dowel hole must be slightly larger for good impression. Cautious in its preparation Retention - tripodism

17. Pin –ledge crown Co-factors of this type retainer Length of span Masticatory forces Amount of torque torsion bending Failure : because of margins the “open up”. Resistance can be increased to this by grooving adjustment to the margin for increased bulk, by keeping the margin away for the area of stress in occlusion

18. ¾ crown  Caries index – low Maximum retention with a minimum sacrifice of tooth structure Its retention depends upon the staple formed by the mesial and distal coverage grooves. Pin in the region of the cingulum Linguo -incisal portion – sufficient thickness

19. Half crown or mesial version of the veneer crown  Teeth that are tilted mesially. Always keep margins away from all stressful situation ; avoid placing margins Abutment preparation should always protected Maintain the proper mesio-distal relation Prevent sensitive cavities Maintain proper relation of occluding teeth Prevent chipping of delicate margin

20. Based on materials

21. All ceramic retainers

22. Metal ceramic retainers

23. All metal retainers

24. All acrylic retainers

25. Resin bonded retainers Specific indications Retainers for FPD with sufficient enamel to etch for retention Splinting of periodontally compromised teeth Stabilizing dentition after orthodontics Medically compromised, indigent, adolescent patients Prolonged placement of interim prosthesis

26. RBP-contraindications Patient wit an acknowledged sensitivity to resinous materials, base metal alloys Facial esthetics of abutment require improvement Insufficient occlusal clearance eg abraded teeth Inadequate enamel surfaces to bond eg caries, existing restorations Incisors‘ with extremely thin faciolingual dimension Exceptionally demanding esthetics

27. Advantages of using RBR NON invasive to dentin Conservative preparation Tissue tolerant –supra gingival margins Reduced cost Less chair time Unaltered casts without removable dies

28. Disadvantages of using RBR Demanding techniques & tooth preparation Education needed about concepts of micro retention Heavy dependence on the laboratory for competent treatment of cast metals and selective waxing to avert overconturing Plaque accumulation is prohibitive , bulky contours Usually restricted to one tooth replacement “Graying out” of teeth that are thin labiolingually at the incisal surfaces

29. Design criteria for retainers

30. Selection criteria for retainers

31. A. Dimension  Deflection of bar  It must not be too long for the number of retainers . The retainers must have adequate retention. Lateral occlusal forces should not be excessive in order to ovoid displacement of the restoration from its abutment

32. Retainers Tooth form and function  Contact area Facial surface Embasures Occlusal elements Occlusal surfaces : cusp fossae , grooves, ridge

33. Occlusal elements  Definite cusp, ridges, grooves Occlusal table 50-60% on diameter Each cusp has a primary ridge with a smaller supplementary ridge on each side. Each primary ridge is at least twice as wide as each supplementary ridge. Occlusal elements  Primary and supplementary ridges are biconvex. The lingual surfaces of anterior teeth have a definite concave surface. Incisal edge of anterior teeth are rounded

34. Selection of retainers Esthetics Strength of tooth Strength of retainer Caries index Occlusion Pulp size Path of insertion Cost

35. Errors Loose retainers Tight fitting retainer Hole /thin areas

36. Pontics Definition Types of pontics Selection criteria Design criteria

37. Pontics Pontics are the artificial teeth of a fixed dental prosthesis that replace missing natural teeth, restoring function & appearance

38. Pretreatment assessment Pontic space Residual ridge contour Residual ridge Gingival architecture preservation

39. Classification of pontics Based on shape of the surface spheroidal

40. Classification of pontics Mucosal contact Ridge lap Modified ridge lap Ovate Conical Non mucosal contact Sanitary / hygienic Modified sanitary

41. Pontic design Optimal pontic design

42. Biologic considerations Ridge contact Oral hygiene considerations Pontic material Occlusal forces

43. Ridge contact

44. Oral hygiene considerations

45. Pontic material

46. Occlusal forces

47. Mechanical considerations Available pontic materials Metal ceramic pontics Resin veneered pontics Fibre reinforced composite resin pontics

48. Esthetic considerations The gingival interface Incisogingival length Mesiodistal width

49. Pontic fabrication Available materials Metal ceramic pontics All metal pontics Available pontic systems

50. Connectors Definition Types of connectors Selection criteria Design criteria Errors

51. Connectors space Vs Contact point Vs Connector Connectors space . The places in which the anterior teeth appear to touch has been referred to as the connector space. The contact points between the anterior teeth are generally smaller areas (about 2 × 2 millimeters) that can be marked by passing articulating ribbon between the teeth. The connector is a larger, broader area that can be defined as the zone in which two adjacent teeth appear to touch.

52. Connectors An esthetic relationship exists between the anterior teeth that is referred to as the 50-40-30 rule . This rule defines the ideal connector zone between the maxillary central incisors as 50 percent of the length of the central incisors. The ideal connector zone between a maxillary lateral incisor and a central incisor would be 40 percent of the length of the central incisor. The optimum connector zone between a maxillary canine and a lateral incisor when seen in lateral view would approximate 30 percent of the length of the central incisor

53. Classification Based on rigidity Based on materials

54. Based on rigidity Rigid connectors Non rigid connectors

55. Classification Tenon-mortise connectors Loop connectors Split pontic connectors Cross pin & wing connectors Rigid connectors Non rigid connectors Soldered connectors Casting connectors

56. Rigid connectors

57. Non rigid connectors

58. Tenon-mortise connectors

59. Loop connectors

60. Split pontic connectors

61. Cross pin & wing connectors

62. Based on materials Metal Metal ceramic All ceramic Resin

63. Size definitions for junctures of VITA In-Ceram® ZIRCONIA bridges The following 3 criteria must be observed when designing the junctures between the abutment copings and the pontic: 1.Depending on the span, the junctures must be designed in accordance with the information given below . 2. Height h should be as large as possible. 3. Height h should be equal to or larger than width b.

64. Errors made with connectors Fall into 3 categories Placement Size & Shape Finishing errors

65. FABRICATION METHODS For RETAINERS PONTICS & CONNECTORS

66. Various methods of fabrication include Conventional wax up –casting Captek crown fabrication CAD- CAM Processing Copy milling

67. Captek crowns CAD-CAM METHOD OF FABRICATION

68. Repair of Pontics C :\Documents and Settings\BBDENTAL\Desktop\1097.pdf

69. Conclusion

70. References

71. Thank you