Overdenture lecture I hope it's helpful

1. Powerpoint Templates
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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.

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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.

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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 .

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