(Overdenture) (1).pdf
- 1. Powerpoint Templates Page 1 Powerpoint Templates Overdenture BY:- Dr.Namarig Siddig
- 2. Content Introduction . Definition. Indications & contraindications . Advantages & disadvantages . Classification . Types of attachments . Abutmens for tooth-supported overdentures. Steps for construction of overdentures . Oral hygein maintenance .
- 3. Introduction • Sequences of extrction : • alveolar ridge resorption & poor foundation. • loss of proprioceptors ( mastication & jaw movements). • So, retention of few remaining teeth would be helpful Overdenture .
- 4. Definition The over denture is a complete or partial denture prosthesis constructed over existing teeth, root structure and/or dental implants.
- 5. a complete or partial removable denture supported by retained roots that is intended to provide & improved support, stability, and tactile proprioceptive sensation and to reduce ridge resorption. (Mosby. Mosby's Dental Dictionary. Elsevier, 2004.).
- 6. Various terms have been used to describe this treatment modality: • Overlay denture, • Telescoped dentures, • Tooth supported dentures, • Hybrid prosthesis, • Crown and sleeve prosthesis, • & Superimposing dentures
- 7. Indications 1. Few remaining teeth are present, not suitable for fixed or RPD. 2. Teeth with periodontal Disease (Reduction of these teeth & decrease the C/R ratio, in turn decrease the hyper mobility of teeth). 3. Pts exhibiting flat ridges have very little support, retention & decrease pt`s ability to manipulate dentures.
- 8. 4. Pts with abnormal jaw size c2, c3 . 5. Acquired or Congenital defects ( cleft palate , microdontia , partial anodontia , D. & A.Imperfecta). 6. Alternative treatment to single dentures.
- 9. Contraindications for Overdentures 1. If any other prosthetic plan can give superior results 2. In cases with poor oral hygiene. 3. Inadequate inter arch distance to accept the denture and abutments. 4. Abutments exhibiting mobility, which exceeds grade III.
- 10. Advantages • 1- Preservation of residual ridge . • Improved occlusal stress distribution .
- 11. • 2- Prevent the loss of teeth. • 3- Preservation of proprioceptive response. • Enhance neuromuscular control , occlusal awareness and biting Force . • Chewing Effeciency
- 12. • 4- Stability, Support. • 5- Retention. (Through Attachments). • 6- Pt acceptance and Psychological benefits. • • 7- Convertibility : ( If the teeth are lost later, the transition and adaptation to complete dentures has been made more gradually) .
- 13. Disadvantages of Overdentures 1. Caries susceptibility 2. Bony undercuts: Limitation of the path of insertion.
- 14. 3. Periodontal breakdown of the abutment teeth : – Gingivitis – Periodontitis – Hyperplasia
- 15. 4. Inadequate reduction of the abutment teeth may increased vertical dimension. 5. Esthetics. (Bulkier) 6. Expense and Time consuming. 7. Removable Prosthesis.
- 16. Powerpoint Templates Page 16 Classification • Classification of Over dentures • Tooth supported Implant supported
- 17. • Complete over dentures . • Partial over dentures. • Fully tooth/implant supported. • Tissue – tooth/implant supported. • Immediate over dentures. • Transitional over dentures. • Definitive over dentures.
- 18. Classification of tooth supported over dentures I. According to time of placement: 1. Immediate overdentures . 2. Interim(transitional). 3. Remote(definitive). 4. Attachment retained.
- 19. Immediate OD • constructed prior to the preparation of the abutment teeth and is ready for insertion after abutment preparation and reduction.
- 21. Interim Overdenture (transitional) • Used in pts in transition phase when mouth preparation is performed and until permenant OD is constructed. • The pt`s old RPD can be modified and used as interim over denture by extending the denture and add artificial teeth using self cure acrylic resin.
- 23. Remote Overdenture (definitive) • These are permanent complete OD constructed over one or more abutment teeth. • Could be acrylic or in conjunction with metal bases to ↑its rigidity & ↓minimize fracture ability.
- 25. • II. According to design and technique of abutment preparation: • 1- Simple tooth reduction of vital abutment.
- 26. • 2- Tooth reduction and cast coping of vital abut. Thimble or dome- shaped
- 28. • 3- Endodontic therapy and amalgam plug • 4- Endodontic therapy with post and coping • 5- Submerged roots : RCT reduced to height below gingival margin.
- 29. • 6- Endodontic therapy with cast coping and attachments
- 30. • 7- Telescopic Over denture
- 31. • Gold or metallic cast Copings and telescopic crowns are a method of improving over denture retention. • These may be conical crowns (semi-parallel wall) with friction adaptation at the marginal area of the abutment and parallel surfaces. • Friction retention is more commonly used in exclusively tooth supported over dentures that are not supported by soft tissue.
- 33. • Partial over denture
- 34. Attachments • An attachment is defined as a mechanical device used for retention and stabilization of a prosthesis.
- 35. • It fall in two categories: • 1. PRECISION ATTACHMENTS • Ready made attachment their component are machined in a especial alloys under precise tolerance. Less wear, Standard parts, easier to repair. • 2- SEMI- PRECISION ATTACHMENTS • Fabricated by the direct casting of plastic, wax or refractory patterns, subject to variables of fabrication, economy.
- 36. Attachment _Retained OD • OD constructed with an incorporated attachment or retentive devices to improve mechanical quality (retention). • Expensive , time consuming. • Need pts with good oral hygiene , low caries index , abutment with good perio. condition and adequate bone support to tolerate extra stress of attachments.
- 37. Types Of Attachments • Rigid : doesn`t allow movement of denture base adequate retention , but more torque on abutment. • Resilient : allow some control of movement , less torque on abutment , but more complex in design and fabrication .
- 38. Forms Of Attachments A. Stud attachments . B. Bar attachments. C. Magnetic attachments.
- 39. • Stud : • Consists of two parts a stud & a housing. • The stud is attached to the metal coping over the prepared abutment , • The housing is embedded in the fitting surface of the acrylic OD.
- 41. Bar attachments • In the form of a bar contoured to run parallel & overly the residual ridge and connects the abutment teeth together. • Provide support , retention and splinting of abutment teeth.
- 45. Magnetic Attachments • Small strong mini magnets are successfully used to retain OD. • One of the magnet pole is cemented in a prepared cavity in the endodontically treated abutment & the other is attached to denture base.
- 48. Powerpoint Templates Page 48 Simple is often the best treatment !
- 49. Steps Of Construction OD • Following steps are generally used : 1.Examination & diagnosis . 2.Abutments selection : a. Perio. condition : at least 6mm of bone around abutment & least mobility less than grade2.
- 50. • Slight mobility is not a contraindication , as a favorable changes in the cr:root ratio.
- 51. b. Positional considerations : select teeth lying in areas where destructive effect on residual ridge hence transfering occ. Load to abutments . E.g : max. ridge opposed by natural teeth, the retention of one or more teeth to be used as OD abutments could prevent the hazards of single complete max. denture. It is preferable to retain ant. Teeth to be used as abutment , this was proved to decrease the rate of bone resorption .
- 53. • Canines are usually prefered because of their centric strategic position in dental arch and their perio. memberane contain nerve receptors which are important For performing masticatory function. • Separate rather than neighbouring teeth are usually preferable. c. Number of abutments :the more the number , the better support , stability & retention of denture.
- 55. • Ideally 2 teeth in each quadrant , • preferable both canines and 1st premolar , to achieve an ideal distribution of stress on residual ridge . • It is even probable to retain 2 teeth , one in each quadrant , these are either bilateral canine or premolar.
- 56. d. Endodontic Factors : RCT is essential or necessary before abutment preparation. The selection of single rooted teeth with obliterated or recessed pulp is usually preferable. while those with necrotic pulp or with periapical lesions may lead to poor prognosis if not properly treated. e. mounted models to determine whether there is adequate space for the over denture, attachments or copings.
- 57. 3. Abutment preparation : a. Endodontic abutment preparation . b. Perio. Preparation ( scaling, root planning, surgical if needed ). c. Abutment reduction & contouring.
- 61. 4. Preliminary impressions : alginate impression , 1ry cast , special tray . 5. Final impression : using rubber base impression material , master cast . Wax pattern for copings are made, then casted into metal.
- 63. • Copings are then cemented , & impression is made using rubber base to obtain cast for coping-covered abutments . 6. Jaw registration : ( face-bow , CR ) .
- 64. 7. Try in : VD should be carefully checked to avoid any probable increase,that may affect occlusion , esthetic & TMJ . Occlusion should also be checked .
- 65. 8. Denture insertion : like that of complete D. - Fitting surface overlying abutment should be properly relieved (0.3-0.5) to avoid pressure on gingival margin & allow proper seating of denture . - Over relieving should be avoided , as excessive space around abutments may cause proliferation of gingival tissues .
- 66. • Abutment contacts denture in function only.
- 67. Oral hygiene maintenance • Maintenance of excellent level of oral hygein (brushing ) . • Floride gel application . • Chlorohexidine mouth wash . • Regular follow up .