Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.

Failures in fpd anish

9,257 views

Published on

FAILURES IN FIXED PARTIAL DENTURES

Published in: Healthcare

Failures in fpd anish

  1. 1. Anish amin
  2. 2. Contents o Introduction o Classification o Biological failures o Mechanical failures o Esthetic failures o Maintenance o Removing of crown and bridges o Conclusion o References
  3. 3. Introduction
  4. 4. Classification
  5. 5. BENNARD G. N. SMITH o Loss of retention o Changes in the abutment tooth o Periodontal disease o Problems with the pulp o Caries o Fracture of the prepared natural crown or root o Movement of the tooth o Mechanical failure of crowns or bridge components o Porcelain fracture o Failure of solder joints o Distortion o Occlusal wear and perforation
  6. 6. o Design failures o Under-prescribed FPDs o Over-prescribed FPDs o Inadequate clinical or laboratory technique o Positive ledge o Negative ledge o Defect o Poor shape and color o Occlusal problems
  7. 7. JOHN F. JOHNSTON o Discomfort o Looseness of FPD o Recurrence of caries o Recession of supporting structure o Degeneration of Pulp o Fractures of bridge components o Loss of veneers o Loss of function o Loss of tissue tone or form o Failure to seat
  8. 8. John Joy Manappallil CLASS I Cause of failure is correctable without replacing restoration. J Prosthet Dent 2008;99:293-298
  9. 9. CLASS II Cause of failure is correctable without replacing restoration; however, supporting tooth structure requires repair or reconstruction
  10. 10. CLASS III Failure requiring restoration replacement only. Supporting tooth structure and/or foundation acceptable.
  11. 11. CLASS IV Failure requiring restoration replacement in addition to repair or reconstruction of supporting tooth structure
  12. 12. CLASS V Severe failure with loss of supporting tooth or inability to reconstruct using original tooth support. Fixed prosthodontic replacement remains possible through use of other or additional support for redesigned restoration.
  13. 13. CLASS VI Severe failure with loss of supporting tooth or inability to reconstruct using original tooth support. Conventional fixed prosthodontic replacement is not possible
  14. 14. Classification of chipping fracture treatments for zirconia-based restorations. o Grade 1: Fracture surfaces were polished. o Grade 2: Fracture surfaces were repaired with resin-based composite. o Grade 3: Severe chipping fractures required replacement of affected prostheses. Int J Prosthodont 2010;23:493–502. Dental materials 2012 :28: 102–111
  15. 15. BIOLOGICAL FAILURES:
  16. 16. Caries Causes o Defective margins and adaptation. o Loose retainers o Residual caries o Poor design
  17. 17. Detection o Visual examination o Comprehensive probing of margins. o Radiographs
  18. 18. MANAGEMENT o Fluoride mouth washes o Dental floss o Diet counseling o Professionally applied topical fluoride o Antibacterial cements and anti- microbial agents should be used to decrease the caries incidence. o Conventional operative dentistry procedures to restore small lesions o Endodontic treatment in case pulp is involved
  19. 19. Pulp degeneration Causes o Excess heat generated during preparation o Excess tooth reduction o Pin point exposure which may go unnoticed. o Occlusal trauma o Poor design o Secondary caries Clinical features o Pulpal sensitivity o Intense pain o Radiolucencies in the periapical region
  20. 20. MANAGEMENT o Use of varnishes and dentin bonding agents which forms an effective barrier and prevents underlying pulp from toxic effects of cement and core materials. o Endodontic treatment of the involved tooth by making an access opening through the crown, once obturated the perforation can be restored.
  21. 21. Periodontal breakdown Causes o Poor marginal adaptation and proximal contact o Over contoured axial surfaces o Excessively large connectors o Large Pontic contacts on edentulous ridge. o Prosthesis with rough surfaces o Heavy occlusal forces o Few abutment teeth o Oversized food table
  22. 22. Clinical features o Gingival recession o Furcations and pocket formation o Mobility (secondary feature).
  23. 23. MANAGEMENT o Proper oral hygiene o Scaling and proper plaque control. o Flap surgery, bone grafts etc. o In case of long span F.P.D., the F.P.D. must be removed and remade with multiple terminal abutments. o Narrowing occlusal table
  24. 24. Occlusal problems Causes o Centric and eccentric interferences o Heavy occlusal forces o Habits like bruxism, clenching Clinical features o Large wear facets o Mobility o Tenderness on percussion o Open contacts o Perforation and cusp fracture o PDL space widening
  25. 25. MANAGEMENT o All interferences should be removed o Occlusal splint o Slightly flatter occlusal table
  26. 26. Tooth perforation Pin holes or pins used for pin retained restorations can be improperly placed and may perforate the tooth laterally.
  27. 27. MANAGEMENT o Extend the tooth preparation to cover the defect o Surgically expose the defect and restore the defect o If not accessible – extraction is done. o Endodontic treatment.
  28. 28. MECHANICAL FAILURES
  29. 29. Loss of retention Causes o Sharp surfaces o Unequal occlusal loads on different part of bridge o Contaminating cementing procedures o Increased cement space o Caries Clinical features o Looseness o Sensitivity to temperatures and sweet o Patient usually complains of recurring bad taste which should be differentiated from similar symtoms caused by poor oral hygiene and periodontal problems
  30. 30. DETECTION: Periodic clinical examination should include, to unseat existing prosthesis by lifting the retainers up and down while they are held between fingers and a curved explorer placed under connector. If casting is loose, the occlusal motion causes fluid to be drawn under casting and when casting is reseated with a cervical force the fluid is expressed, The examination should be done without drying the tooth.
  31. 31. MANAGEMENT o Re-cementation of old prosthesis o Providing abutment with grooves, boxes etc. o Post and core treatment
  32. 32. Connector/solder joint failure Causes of connector failure o Heavy occlusal forces o Internal porosity o Small connector size Causes of solder joint failure o Porosity o Failure to bond to surface of metal o Improper flow due to decreased width between joining parts
  33. 33. Detection Wedges are placed beneath the connector to separate the fixed partial component to conform diagnosis
  34. 34. MANAGEMENT o Fabrication of new prosthesis. o Occasionally an inlay like dovetailed preparation can be made on metal and this casting can be cemented to stabilize the prosthesis.
  35. 35. Occlusal wear and perforation Causes o Heavy occlusal forces o Clenching, bruxsim lead to accelerated occlusal wear o Inadequate clearance Clinical features o Attrition of opposing teeth o Polished facets of the retainers or pontics o Gingival recession o Peroforation of the prosthesis
  36. 36. MANAGEMENT o If perforation is detected early a restoration can be placed to seal the area. o If metal surrounding perforation is extremely thin a new prosthesis should be fabricated. o If occlusal surfaces are covered with porcelain, opposing natural teeth shows dramatic wear of enamel, so go for metal crowns to minimize the wear.
  37. 37. Tooth fracture
  38. 38. Coronal tooth fracture Causes o Caries o Excessive tooth reduction o Interferences o Forcibly seating or removing the fixed partial prosthesis o Preparation mainly containing restorative material
  39. 39. MANAGEMENT o If defect is small it is restored with amalgam, resin o If defect is big/ large a new prosthesis is fabricated so that it wil cover the fracture area o If fracture causes pulp exposure endodontic treatment followed by post and core is necessary prior to fabrication of new prosthesis.
  40. 40. Root fractures Cause of Root Fracture: o Most often due to trauma o Forceful seating of posts
  41. 41. Porcelain fracture Majority of metal ceramic fracture can be attributed to improper design of metal framework or problems related to occlusion.
  42. 42. a) CAUSES OF METAL CERAMIC FAILURE: 1) FRAMEWORK DESIGN: o Sharp angles/ extremely irregular areas will serve as points of stress concentration. o Overbuilt porcelain unsupported by metal o Overly thin metal casting o When the angle between the veneering surface and non veneering aspect of casting is less than 90degree
  43. 43. 2) OCCLUSION o Centric/eccentric occlusal interferences o Heavy occlusal forces o Habits like clenching, bruxism
  44. 44. 3) METAL HANDLING PROCEDURES:- o Improper handling o Bubbles at the interface of metal and ceramic o Excessive oxide formation on alloy
  45. 45. 4) PREPARATION, IMPRESSION AND INSERTION
  46. 46. 5) METAL AND PORCELAIN INCOMPATIBILITY o In rare instances an alloy and porcelain are found to be truly incompatible, and successful bonding without loss of veneer/ cracking is impossible. o Ni-Cr alloy is choice of material for long bridges.
  47. 47. MANAGEMENT o Fabrication of new prosthesis o Resin materials are used to rebuild the porcelain form in area where fracture has occurred. o If fracture is due to heavy occlusal forces, the contact should be avoided at the metal ceramic junction and it should be at least 1.5mm away from the junction.
  48. 48. o A more permanent repair is possible when adequate metal thickness is available. o o If there is any risk of pontic area flexing, porcelain should be carried on to the lingual side of the pontic to stiffen them further.
  49. 49. SLEEVE CROWN o When a considerable portion of porcelain is lost from labial/ incisal surface of a retainer or pontic it is often possible to repair than replace the entire unit. o The porcelain facing is removed with some of the underlying metal from the labial surface and incisal third of the palatal surface. o An impression is taken of this and 2 adjacent units. The technician is then asked to make metal ceramic crown that will have two surfaces instead of usual four. This sleeve crown is then cemented in usual way. If too little porcelain is removed from original unit, the new sleeve crown will feel slightly bulky.
  50. 50. B)PORCELAIN JACKET CROWN FAILURES: Causes o Heavy occlusal forces o Inadequate clearance o Clenching /bruxism
  51. 51. MANAGEMENT o Tooth preparation should be adequate but not excessive. o Minor defects can be restored with resin. o Severely chipped all porcelain crowns must therefore be replaced by new crown.
  52. 52. TYPES OF CERAMIC FRACTURE: a) Vertical fracture:- If tapered finish line is used, restoration contacts the tooth on a sloping surface resulting in forces that attempt to expand the restoration which are not well resisted by porcelain, leading to vertical fracture.
  53. 53. b) Facial cervical fracture Fracture often assumes a semi lunar form. Generally occurs with short preparation form. Inciso-cervical length should be 2/3 to ¾ that of final restoration. When preparation is short, forces at the incisal edge attempt to tip the restoration facially and cause cervical porcelain fracture. c) Lingual Fracture Result of inadequate tooth reduction (1mm) lingually. Occlusal forces is directed cervically to cingulum of the preparation, fracture also occurs when forces are more of shear in nature.
  54. 54. Pjetursson et al. performed a systematic review of the 5-year survival rates of all-ceramic single crowns and to compare them with the survival rates of metal–ceramic crowns and to describe the incidence of biological and technical complications. A total of 34 studies met the inclusion criteria. Based on meta- analysis, the five-year survival rate for ceramic crowns was estimated 93.3% compared with 95.6% for metal–ceramic crowns. Clin Oral Implants Res 2007;18(Suppl. 3):73–85.
  55. 55. 6) CEMENTATION FAILURES Causes of cement failure o Cement selection o Old cement o Prolonged mixing time o Thin mix o Cement setting prior to seating o Inadequate isolation o Incomplete removal of temporary cement o Thick cement space o Inclusion of cotton fibers o Insufficient pressure
  56. 56. 7) WEAR AND TEAR Crown and bridge may fail over a period of time because of wear and tear and this is usually no body's fault.
  57. 57. 8) DESIGN FAILURES: a)Abutment preparation design o Taper of preparation :- o Ideal taper for good retention is 70 with minimum cement in between. However, it is not possible to achieve this taper clinically without producing some undercuts/ damaging the adjacent teeth.
  58. 58. Length of preparation:- Minimum cervico-incisal height is that which allows the tooth structure to interfere with arc of rotation as tipping forces attempts to cause rotation around a fulcrum located at the finish line on the opposite side of the tooth.
  59. 59. Circumferential irregularity o Circumference of teeth is usually irregular in form and when tooth is uniformly reduced an irregular shape is formed which enhances ability of restoration to resist both tipping and twisting forces. o When tooth encountered is round/ short/ over-tapered intentionally formed irregularities such as boxes, grooves may be used to produce areas that interfere with dislodgement of restoration.
  60. 60. Occlusal irregularities o Irregular reduction according to the occlusal plane produces an corrugated form. o Aids in resistance to dislodging forces, flat reduction provides little interference and unnecessary reduces the length of preparation.
  61. 61. Finish line requirements Supragingival margins are more acceptable than subgingival as they aid in proper oral hygiene maintenance. They also reduces pulpal sensitivity as they are usually in enamel.
  62. 62. Structural Durability Functional cusp bevel: Bevel should be given on maxillary lingual cusp and mandibular buccal cusp at an angle of 450 to provide space for adequate bulk of metal in an area of heavy occlusal contact.
  63. 63. Inadequate Bridge Design Underprescribed FPD Include design that are unstable or have few abutment teeth e.g. Cantilever bridge carrying pontics that cover too long a span or a fixed movable bridge where again span is too long or abutment teeth with too little support have been selected.
  64. 64. Overprescribed FPD Dentist may include more abutment than are necessary and fate usually dictates that it is the unnecessary retainer that fails 1st and 2nd premolar and 2nd molar included to replace 1st molar or use of 345 on either side to replace incisors in the upper arch.
  65. 65. Marginal Deficiencies: Positive ledge (overhang):- It is an excess of crown material protruding beyond the margin of preparation. These are more common with porcelain . However, it is often possible to correct them without otherwise disturbing the restoration by grinding and polishing in situ. Negative ledges:- In a deficiency of crown material that leaves the margin of preparation exposed with no major gaps between the crown and the tooth. It is fairly common fault particularly with metal margins. But one that is difficult or impossible to correct at try in stage.
  66. 66. Pontic Design Tissue contact of pontic:- Extensive area of tissue contact is cited as major cause of failure. Area of contact should be small and convex. Mesial, distal, lingual gingival embrasures should be wide open to allow easy cleaning. Contact between the pontic tissue should allow floss to be passed from one retainer to the other.
  67. 67. Dowel Design: o If a dowel is used its extension into the root must at least equal the length of the crown. o A minimum of 4 mm gutta percha and more if possible should remain to prevent dislodgement and subsequent leakage. o To prevent fracture, encirclement of 1-2 mm of vertical axial tooth should be done.
  68. 68. ESTHETIC FAILURES
  69. 69. COLOUR MISMATCH This could be the result of o Inability to match the patient natural teeth with available porcelain colors. o Shade selection may have been inadequate. o Metamerism also leads to poor color match. o Insufficient tooth reduction / failure to properly apply and fire the porcelain may have created a restoration that does not match the shade guide or surrounding teeth.
  70. 70. Preoperative view of fractured porcelain on pontic of 3-unit bridge. Preparation of the exposed metal creating undercuts in the metal Application of metal bonding agent. Application of resin opaquer. REPAIRING PORCELAIN-METAL RESTORATIONS WITH COMPOSITE RESIN
  71. 71. Placement of composite resin. Completed composite resin repair of the lateral incisor matrix is placed on gingival area of pontic to shape the composite resin repair
  72. 72. The most common complications associated with conventional fixed partial dentures were o caries (18% of abutments ), o need for endodontic treatment (11% of abutments ), o loss of retention (7% of prostheses), o esthetics (6% of prostheses), o periodontal disease (4% of prostheses) o tooth fracture (3% of prostheses), o prosthesis/porcelain fracture (2% of prostheses). J Prosthet Dent 2003;90:31-41.
  73. 73. Rinke et al in 2013 conducted a study on prospective evaluation of zirconia posterior fixed partial dentures for 7 years. After a mean observational period of 7 years, the survival and success rates of zirconia-based posterior FPDs were inferior to those published for metal ceramic FPDs. Int J Prosthodont 2013;26:164–171.
  74. 74. MAINTENANCE: o Following cementation patient should be instructed in particular oral hygiene procedures necessary. o Crown needs brushing and flossing just as a sound tooth, but the position of margin and particular need for care in cleaning should be demonstrated to the patient.
  75. 75. o In case of high decay rate/ decreased salivary flow, dietary advise should be given and use of fluoride rinses (0.05%) encouraged. o In bruxers suitable bite appliances should be given.
  76. 76. Removing of crown and bridges Bridge tapping device
  77. 77. o By cutting through the casting vertically on the buccal and lingual walls and then across the occlusal surface. o Ultrasonic scalers to break the cement seal. o Chisel and mallet
  78. 78. Richwill crown removal
  79. 79. REVIEW APPOINTMENTS: Restoration is examined with a sharp probe to detect any deficiency, mobility of the tooth. If mobility is seen without de-cementation the presence of periodontal pocket should be determined and occlusion checked, where excessive loads are the cause. Bleeding on probing, loss of attachment indicate active disease and patient should be encouraged for better cleaning. Periodic radiographs is essential in patients with high risk of dental caries.
  80. 80. Conclusion Failures in FPD construction for the most part is due to attempted short cuts or positive indifference and inexcusable ignorance on the part of those concerned with building the prosthesis. Also an FPD can just wear out and this cannot be called as failure as no lifetime guarantee can be given. The fundamentals of fixed prosthodontic therapy modality have to be followed strictly, failure of which will lead to the failure of the prosthesis itself.
  81. 81. References o Rossenstiel –textbook fixed partial dentures o Dykema R.W., Goodacre C.J. and Phillips R.W. “Johnston’s Modern Practice in Fixed Prosthodontics”. Fourth Edn, W.B. Saunders Co. Philadelphia, London. o Brown M.H. “Causes and prevention of fixed prosthodontic failures”. J. Prosthet. Dent. 1973; 30: 617-622. o Barreto M.T. “Failures in ceramometal fixed restoration”. J. Prosthet. Dent. 1984; 51: 186-189. o Charles et al, clinical complications in fixed prosthodontics, J Prosthet Dent 2003;90:31-41.
  82. 82. o Pruden K.C. “Abutments and attachments in fixed partial dentures”. J. Prosthet Dent. 1957; 7: 502-510. o Burke E.J.T. and Grey N.J.A. “Repair of fractured porcelain units: alternative approaches”. Br. Dent. J. 1994; 176: 251-256. o Chung K.H. and Hwang Y.C. “Bonding strengths of porcelain repair systems with various surface treatments”. J. Prosthet. Dent. 1997; 78: 267-273. o Walten J.N., Gardner F.M. and Agar J.R. “A survey of crown and fixed partial denture failures: Length of service and reasons for replacement”. J. Prosthet. Dent. 1986; 56: 416-421. o Heintze SD, Rousson V. Survival of zirconia- and metal-supported fixed dental prostheses: a systematic review. Int J Prosthodont 2010;23:493–502
  83. 83. o Kenneth j. anusavice. standardizing failure, success, and survival decisions in clinical studies of ceramic and metal–ceramic fixed dental prostheses replacement. Dental material 2012 ;28: 102–111 o John joy manappallil. classification system for conventional o crown and fixed partial denture failures. j prosthet dent 2008;99:293- 298 o Pjetursson be, sailer i, zwahlen m, hammerle ch. a systematic review of the survival and complication rates of all-ceramic and metal– ceramic reconstructions after an observation period of at least 3 years. part i: single crowns. o clin oral implants res 2007;18(suppl. 3):73–85. o Raigrodski, contemporary materials and technologies for all-ceramic fixed partial o dentures: a review of the literature, j prosthet dent 2004;92:557-62

×