Overdenture

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Overdenture

  1. 1. OVERDENTURE Dr. Talib Amin GDC Srinagar
  2. 2.  Introduction • Extraction of teeth is followed by continuous ridge resorption and poor denture foundation • Loss of periodontal receptors responsible for proper masticatory function and accurate jaw movements. • Retention of few remaining teeth will preserve alveolar bone and preserve periodontal receptors.
  3. 3. A removable partial denture or complete denture that covers & rests on one or more remaining natural teeth, the roots of natural teeth, &/or dental implants. GPT 8 •Tooth supported denture •Overlay denture/ Onlay denture/ Inlay denture • Telescopic denture • Superimposed prosthesis • Hybrid denture •Biological denture •Coping prosthesis  Definition
  4. 4. RATIONALE FOR OVER DENTURE (LOGICAL BASIS)
  5. 5. o The roots of the tooth offers the best available support for occlusal forces. o Accelerated rate of bone resorption is prevented. o It increases pt’s manipulative skills in handling the denture. (periodontal membrane is preserved ,thus proprioceptive impulses, part of myo-facial complex are retained.)
  6. 6. Occlusal forces are transmitted on oblique fibres and dissipated as tension resulting in osteoblastic respose Heartwell 4th Ed page 503
  7. 7. • LEDGER (1856)prescribed a prosthesis resembling an over denture. His restorations were referred to as plates covering fangs (teeth) • EVANS(1888) described a method for using roots to retain restorations after intentional devitalisation of the roots. • ESSIG(1896) described a telescopic‐like coping
  8. 8. • 1906–WILLIAM HUNTER put forward his focal sepsis theory and this dealt a great blow to the overdenture mode of treatment. The main point of contention was that the exposed roots act as foci of infection. • 1916‐PEESO was employing removable telescopic crowns. Later on, the bar type of construction was developed.
  9. 9. • MILLER (1958 ) published his classic article where the retention of previously unusable teeth and their advantageous use in overdenture treatment was explained as a basic tenet in management. • Prieskal(1968)described various commercially available overdenture attachments Preiskel HW. Prefabricated attachments for compete overlay dentures. Br Dent J 1967;123:161.
  10. 10. ADVANTAGES
  11. 11. • Ridge preservation • Proprioception • Superior patients acceptance • Open palate possible • Definitive vertical stop for denture base • Support, stability and retention are improved • Less trauma to supporting tissues • Fever post insertion problems than conventional complete denture • Conversion to complete denture • Increased biting force (Pacer FJ, Bowman DC. Occlusal force discrimination bydenture patients. J Prosthet Dent 1975;33:602–9) • Physiological Advantage
  12. 12. DISADVANTAGES
  13. 13.  Caries susceptibility.  Periodontal disease around abutments  Bony undercuts. (due to limited path of insertion)  Encroachment of inter occlusal distance.  Meticulous oral hygiene is required.  Time consuming.  Technique sensitive.
  14. 14. INDICATIONS
  15. 15.  Patient with badly worn teeth.  Pt. with few natural remaining teeth.  Poor prognosis for routine complete denture.  Congenital or acquired intra oral defects.  Mandibular arch where loss of bone is more rapid  Edentulous maxilla opposing intact mandibular dentition.  Post traumatic or post surgical cases.  Severe attrition and loss of vertical dimension.  Young patient.  Cleft palate causing large free way space.  Hypodontia  Tooth wear cases
  16. 16. CONTRAINDICATIONS
  17. 17.  High caries index.  Poor oral hygiene.  Poor prognosis of abutment.  Reduced inter-arch space.  Undercuts.  Sufficient attached gingiva not present.  Where endo and perio treatment can not be performed satisfactorily.  Grade III mobility
  18. 18. Classification
  19. 19.  ACCORDING TO METHOD OF ABUTMENT PREPARATION (Heartwell)
  20. 20. OVERDENTURE Tooth supported Implant supported Non Coping Coping Attachments Short Long Stud Bar Magnets
  21. 21.  BASED ON TYPE OF OVER DENTURE (Brewer and Morrow) IMMEDIATE TRANSITIONAL / INTERUPT DENTURE REMOTE / PERMANENT DENTURE
  22. 22.  Immediate over denture • Constructed prior to preparation & ready for insertion after preparation & reduction • It enhances patients ability and adaptability to wear dentures
  23. 23.  Interim over denture • Used for patients in transition or preparation phase until permanent overdenture constructed • Patient old partial denture can be modified & used by extending the denture and add new artificial teeth using self cure acrylic resin
  24. 24.  Remote or Definitive over denture • Conventional complete over denture constructed over one or more abutment teeth • Could be made entirely of acrylic resin or in conjunction with metal bases
  25. 25. NON COPING ABUTMENTS Selected tooth abutments are reduced to a coronal height of 2 to 3 mm. and then contoured to a convex or dome shaped surface. Most teeth required endodontic therapy and in final step are prepared conservatively to receive an amalgam or composite type restoration.
  26. 26.  Advantages • Least expensive option • More amenable to treatment, retreatment and modification in contingency situations • Greater degree of flexibility in formulating treatment plan
  27. 27. ABUTMENTS WITH COPINGS • Coping is a cover for the exposed tooth surface • Cast metal coping with a dome shaped surface and a chamber finish line at the gingival margin are fabricated and cemented.  Short coping  Long coping
  28. 28. SHORT CAST COPINGS • Short copings are 2-3 mm and normally require endodontic therapy because the required coronal root reduction would expose the pulp.
  29. 29. Long cast coping Long cast copings are normally 5-8 mm long, conservative reduction of coronal tooth structure is done. The end result is long ellipsoidal shaped coronal coping and a larger crown root ratio.  Consequently, long cast coping require a greater level of osseous support.
  30. 30. ABUTMENT WITH ATTACHMENTS
  31. 31. Attachments are small precision devices. Objective is to improve retention of denture base. Most attachments are secured to abutment by a cast coping. Consists of two parts o Male o Female
  32. 32. Requirements for the Attachments Patients should have a low caries index. Perform proper home care Sound periodontal health Proper bone support
  33. 33. Disadvantages of attachments Added time Expensive Difficult to construct Repair is difficult Requires careful manipulation by the patient, not recommended for mentally and physically handicapped
  34. 34. Rigid attachment • Doesn’t allow movement of denture base • Provide adequate retention • May induce more torque on abutment Resilient attachment • Allows some control of movements • Induces less torque on abutments
  35. 35. 1. Stud attachment  simplest of all attachments Consists of two parts • The stud(male component) usually attached to metal coping cemented over prepared abutment • Housing (female component) embedded in the fitting surface of over denture
  36. 36. Extra radicular stud attachment Male element projects from the root surface The stud is attached to the metal coping cemented over the prepared abutment, while the housing is embedded in the fitting surface of denture. • Gerber • Ceka • Rotherman
  37. 37.  Gerber anchor • Readily replace able male or female attachments by unscrewing the worn unit.
  38. 38.  Rothermann attachment • Male part consists of groove • Female part (housing) consists of C shaped ring which fits in deeper part of retaining groove
  39. 39.  Ceka attachment • Male part round with cementable titanium post • Female part in titanium alloy with replaceable plastic part that is flexible and compressible (split vertically into four sections )
  40. 40.  Other attachments of importance Ancrofix attachment Introfix attachment Schubiger attachment Quinlivan attachmentr
  41. 41. Intra radicular stud attachment  The stud is attached to the fitting surface of the denture and the housing is incorporated in the abutment. • Zest Anchor
  42. 42.  Zest anchor system • Female sleeve is cemented in post space made within the root • Male portion consists of nylon
  43. 43. Advantage Disadvantage
  44. 44. • The attachments should be aligned to each other • Should be in line with the path of insertion of the denture. • A divergence of 10 degree can be tolerated • Significant divergence of roots or implants should be considered a contra indication for this approach.
  45. 45. • One stud attachment on either side of the arch will suffice; the remaining roots can be covered by simple copings. • Increasing the number of attachments does not necessarily increase retention; it may contribute to improved stability, but leads to a weaker structure. • Two stud attachments on adjacent roots are unnecessary as it would complicate hygiene measures and also weaken the denture base
  46. 46. Bar attachments o A bar contoured to connect abutment teeth together, run parallel & overlie residual ridge o Preformed metal or plastic. The purpose of using bars are: • Splinting of abutment teeth • Retention and support of prosthetic appliance
  47. 47. o Spreads loading o Soldered to copings  Increased torque  Plaque control difficult  Relining complicated
  48. 48. • The bulk of bar and related structures raises several problems. • Vertical and buccolingual space requirements limit their applications. • Bar attachments also demand more oral hygiene maintenance from the patients.
  49. 49. Bar units o Rigid type o No movement between bar and sleeve o Transmits occlusal stresses totally to abutments o Thus Tooth born
  50. 50. Bar joints o Resilient o Allow some movement of rotational type between bar and sleeve. o Utilize support both from residual ridge and abutment o Thus tooth tissue born
  51. 51. Bar attachments of importance • Haden bar • Dolber bar • Baker clip • Ackerman clip and CM clip • King connector
  52. 52.  Magnetic attachment o Detachable keeper element • Made of stainless steel that is fixed to abutment teeth by Cementing Screwing o Denture retention element • Has paired, cylindrical Co- Sm magnets axially magnetized and arranged with their opposite poles adjacent
  53. 53. • Small, strong mini magnets • One of poles cemented in the prepared cavity in endodontically treated abutment and the other attached to denture base.
  54. 54. DIAGNOSIS, TREATMENT PLANNING AND CASE SELECTION
  55. 55. No Diagnosis No Treatment If you don’t know where you go, you never get lost
  56. 56. History Examination  Articulated diagnostic casts Full mouth radiographs Overall patient concerns
  57. 57. Possibility of fixed or removable partial dentures: • If the remaining teeth are capable of supporting a fixed or removable prosthesis, then that should be the primary mode of treatment.
  58. 58. Patient age • Extractions are to be avoided in a young patient as far as possible, so overdenture do play a major role in treating young patients with mutilated dentition.
  59. 59. Factors influencing selection of abutment teeth • Periodontal status • Mobility • Location • Endodontic considerations • Cost
  60. 60. Periodontal & Mobility status • Ideally tooth should present minimal mobility, have acceptable bone support and be responsive to periodontal therapy. • Circumferential band of attached gingiva is an absolute necessity. • Compromised teeth with good treatment prognosis are suitable candidates even when horizontal bone loss is present
  61. 61. • Slight tooth mobility with horizontal bone loss is not contraindicated as decrease in C- R ratio required for abutment preparation improves mobility. Reduces the length of the lever arm • Vertical bone loss particularly accompanied by Class II or III mobility excludes tooth selection.
  62. 62. Abutment location • Ideal: Two teeth per quadrant (stress is distributed over a rectangular area) • Tripod is next most favorable form for support and stability. • Clinical experience recommends at least one tooth per quadrant.
  63. 63. • Isolated teeth are preferred to several adjacent teeth as inter dental areas are difficult to clean and susceptible to gingivitis. Robert M. Morrow, Colonel , Ret. USAFDC, Virginia, 1970
  64. 64. • Anterior mandibular ridge is most vulnerable to time dependent RRR • Canines and premolars are regarded as best overdenture abutments
  65. 65. • In maxilla central incisors are ideal as overdenture abutments( Protects pre maxilla) • Canines are next (Longest Root) • Lateral incisors(widely spaced, facilitating plaque control)
  66. 66. Endodontic Status • Preserve teeth that are already endodontically treated. • Usually anterior teeth are preferred as they are easier to prepare and economical too. • Whenever pulpal recession to the extent of calcification has occurred , endodontic treatment usually can be avoided.
  67. 67. • Ettinger in 1990 showed that the most common cause of abutment failure was vital teeth developing periapical lesions as a result of pulpal necrosis ( 53.8%).
  68. 68. According to Zarb 13th edition • After 5-6years, about 10% of abutment teeth supporting overdentures were lost Periodontal disease 70% Caries 25% Endo complications 5%
  69. 69. • Patient is motivated to maintain adequate oral hygiene to prevent abutment loss. • Patients must clean all exposed dentin and use 0.4% stannous fluoride daily. Thayer, H. H. Overdenture and the periodontium. DCNA 24:369-377, 1980.
  70. 70. PREPARATORY TREATMENT FOLLOWING SEQUENCE OFT TREATMENT CAN BE USED AS A GENERAL GUIDE BUT MAY NOT BE SPECIFICALLY APPLICABLE TO ALL PATIENTS: 1. Construct an immediate treatment clasp less denture. It replaces missing and hopelessly involved teeth for esthetic reason and retain jaw relations. 2. Remove hopeless teeth and insert the removable prosthesis. 3. During the healing period, institute the periodontic and endodontic treatment.
  71. 71. TOOTH PREPARATION • Remove sufficient tooth structure to provide favorable root crown ratio. • Reduce the crown length up to 2 mm above the gingival crest or extend a chamber type margin slightly beneath free gingival margin. • Taper the preparation in occlusogingival direction.
  72. 72. • Consequently optimal abutment preparation is achieved that has following features: • Simple • Short • Convex • Dome shaped • Chamfer finish line
  73. 73. The finished tooth with cast coping is male member of denture. The female member is part of denture base.
  74. 74. • As a cost containment method, use of cast coping has been largely eclipsed by composite and alloy restoration with or without adjunctive inter radicular attachments
  75. 75. COPING FABRICATION • Make an accurate impression of the abutment and pour a die. • Carve the wax pattern. • Cast the coping • Cement the polished coping to the tooth. • Instruct the pt. in home care of abutment tooth.
  76. 76. IMPRESSION FOR THE DENTURE • Follows the same technique that is used in constructing a conventional complete denture. • PRELIMINARY IMPRESSION • BORDER MOLDING • FINAL IMPRESSION
  77. 77. RECORD BASES AND OCCLUSAL RIMS RECORDING MAXILLO MANDIBULAR RELATIONS • A face bow transfer is used to relate the maxillary cast to the articulator. • Jaw relations and arrangement of teeth for phonetics are verified at the time of try in.
  78. 78. TOOTH SELECTION • Artificial teeth placed over the abutment teeth should be acrylic resin. • When teeth in opposing arch have i) Gold occlusal surfaces ---- occlusal surfaces of artificial teeth should be either gold or acrylic resin, preferably gold. ii) Restored with porcelain --Porcelain artificial teeth are preferred. iii) Natural teeth ---- Gold occlusals are preferred, otherwise acrylic
  79. 79. TRYING THE DENTURE • Verify jaw relation records • Make eccentric jaw relation records and adjust the articulator. • Assure esthetic acceptability by the patient. • Verify phonetic acceptability. LABORATORY PROCEDURES • CONTOUR THE WAX • FLASK THE DENTURE • ELIMINATE THE WAX • PRAPARE RESIN • PACKING • RELIEF FOR MARGINAL GINGIVA
  80. 80. DENTURE INSERTION • Review instruction in denture use and care. • Use pressure disclosing paste to locate contacts between female and male members. • Evaluate the tissue side of denture base and borders for pressure areas and over extensions. • Perfect the occlusion by remounting and selective grinding. • Place pt. on recall system After insertion Final try in
  81. 81. SUBMERGED VITAL ROOTS Selected vital roots are selected and reduced to 2 mm. below the crestal bone and then covered by mucoperiosteal flap Still in experimental stage. The method is innovative attempt to obviate the basic problems like caries, gingivitis, periodontitis Major post operative problems are: development of dehiscences over retained roots and pulpal pathologies.
  82. 82. Implant supported Over denture
  83. 83. The minimum acceptable standard of care for the treatment of the edentulous mandible should be the provision of interforaminal osseo- integrated dental implants to support and retain the complete lower denture. Quintessence International, volume 34, Number 1, 2003
  84. 84. Why implant OD and not Full arch Fixed Implant Prosthesis • Lesser Implants • Less cost • Previous Denture wearer • Denture is less complicated than Implant Fixed Prosthesis • Overall esthetic objectives can be addressed and achieved with greater ease
  85. 85. Inclusion Criteria for Implant Placement • PT. DESIRE FOR IMPLANT TREATMENT • SYSTEMIC HEALTH STATUS, WHICH PERMITS A MINOR SURGICAL PROCEDURE • SUFFICIENT BONE QUANTITY TO ACCOMMODATE PRESCRIBED IMPLANT DIMENTIONS • PT. WILLINGNESS AND ABILITY TO MAINTAIN ORAL STATUS Prosthodontic Treatment for edentulous Patients Zarb 13th edition Pg 331
  86. 86. Exclusion Criteria for Implant Placement o RESIDUAL RIDGE DIMENTIONS DO NOT ACCOMMODATE PREFFERED IMPLANT DIMENTIONS o COMMUNICATION WITH PT. IS NOT POSSIBLE o PT. HAS HISTORY OF SUBSTANCE ABUSE o GENERAL HEALTH CONDITIONS PRECLUDEA MINOR SURGICAL INTERVENTION o LOCAL ANAESTHESIA WITH VASOCONSTRICTER IS CONTRAINDICATED o IMMUNOSUPPRESIVE THERAPY, PROLONGED INTAKE OF ANTIBIOTICS OR CORTICOSTEROIDS, OR BRITTLE MEABOLIC DISEASE HISTORY Prosthodontic Treatment for edentulous Patients Zarb 13th edition Pg 331
  87. 87. TREATMENT FOR A PATIENT WITH IMLANT OVERDENTURE
  88. 88. Treatment Planning concerns for patient with Implant supported Overdenture • Number of Implants and their location • Preferred denture retention devices- The Attachment Systems
  89. 89. Maxilla • 4- 6 Implants and infrequently connected using a bar. • Implant length preferably 10mm or longer.
  90. 90. Mandible • 2 un-splinted implants with a selected attachment method (current & most frequent) between canine and lateral incisor. • 12 mm inter implant distance required • When shorter implants are used more number of implants can be placed
  91. 91. A healing period of 3-4 months for mandibular implants and 6 months for maxillary implants ( conventionally loading) has been traditionally observed.
  92. 92. • Selection of a specific attachment for an implant overdenture depends on the following; • - Type of overdenture fabricated. • - Location of implants on the ridge. • - The condition of the residual alveolar ridge. • - Dexterity of the patient. • - Psychosocial needs of the patient. • - Relative need for stability and retention. • - Length of implant used. As a general rule, more complicated and sophisticated the attachment, more difficult it is to repair and maintain.
  93. 93. ATTACHMENTS • FEMALE PORTION -PROSTHESIS • MALE PORTION –IMPLANTS • Ball Attachments O-ring System Locator System • Bar & Clip Attachments CM Bar & Rider/Ackermann Clips Dolder Bar System Häder Bar System/EDS System
  94. 94. • Over denture is an excellent viable treatment alternatives. • Emphasis must be placed on proper patient selection, pt. motivation, basic prosthodontic principle & detail program of home care instruction & frequent recall. • The overdenture is an out standing mode of treatment. Breakdown in tooth structure or a breakdown in their periodontal support immediately negates an overdenture concept.  IF WE ARE TO SUCEED, WE MUST CONTROL THE FACTORS THAT JEOPARADIZE SUCCESS.
  95. 95. REFERENCES
  96. 96. • Essentials of complete denture prosthodontics – Sheldon Winkler 2ndedition • Prosthodontic treatment for edentulous patients –Zarb-Bolender 12thedition • Complete denture prosthodontics –John J. Sharry • Syllabus of complete dentures –Charles M. Heartwell & Arthur O. Rahn 4thedition • Dental Implant Prosthetics –Carl E . Misch • Articles from different journals mentioned earlier

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