This document discusses overdentures, which are complete or partial dentures constructed over existing teeth, roots, or implants to provide additional support, stability, and retention. It describes different types of overdentures including tooth-supported and implant-supported overdentures. Various techniques for constructing tooth-supported overdentures are presented, including different ways of preparing and covering abutment teeth. Indications and contraindications for overdentures are also outlined.

1. Prof. Dr. Ahlam El-Sharkawy
Pharos University in Alexandria

2. Introduction
 Extraction of teeth followed by continuous ridge
resorption & poor denture foundation
 Loss of periodontal receptors responsible for proper
masticatory function & accurate jaw movements
 Retention of few remaining teeth to support denture
will preserve alveolar bone & preserve periodontal
receptors

3. Definition of overdentures
 Complete or partial denture constructed over existing
teeth, roots or implants for providing additional
support, stability & retention
 Called also:
Overlay denture
Overlay prosthesis
Superimposed prosthesis

4. Types 0f over-Dentures.
 -Tooth supported over-dentures.
- Implant supported over- denture.

5. Prof. Dr. Ahlam
El-Sharkawy

6. Indications
1. Cases having few hopeless teeth unsuitable as
abutments for fixed or removable bridges
2. Patient having few remaining teeth with periodontal
disease.
3. Patient with abnormal jaw size or position
4. Patient with congenital or acquired defects as cleft
palate ,dentinogenesis imperfecta
5. Patient with single denture
6. Patient exhibit flat ridges

7. Contra-indications
1. Mentally or physically handicapped
2. Patient can’t be motivated to develop good oral
hygiene
3. Inadequate intermaxillary space
4. Teeth with grade III mobility or insufficient zone of
attached gingiva

9. 1- submerged roots
 Abutments roots are endodontically treated .
 Reduced in height to a level below gingival margin

10. 2- dome shaped abutment with
amalgam plug mmmmmm
 Abutments reduced to be 1-2 mm above gingival
margin to reduce lateral force & torque
 Endodontic treatment is necessary
 The root canal is filled with gutta percha
 The opening is sealed with amalgam plug.
 The abutment is contoured to attain dome- shape.
 Used in patient with low caries index &good oral
hygien.

11. 3- dome shaped abutments with
cast copings
 Abutment are endodontically treated & reduced to 1-2
mm above gingival margin
 Metal dome shaped cast coping constructed to cover
abutment
 The metal coping has a short post cemented into root
canal to retain the coping

12. 4- abutments with telescopic
crowns
 Abutment teeth are either vital or endodontically
treated & contoured to tapered configuration
 Tapered metal copings constructed &cemented over
abutments
 Denture constructed with metal crowns having
veneered facings

13. 5- abutments with slight tooth
reduction & cast copings
 Abutments are minimally reduced
 With or without endo treatment
 Covered with cast metal coping “long coping
abutment”. This type is rarely followed because it
 requires adequate ridge space

14.  Endodontically treated, reduced & covered with metal
coping
 Coping has a long post to help retention
 Attachment added either by soldering or during wax
pattern
6- abutments with an added form
of attachment

15. Types of tooth supported Over-dentures
1. Immediate over-denture
2. Interim over-denture
3. Definitive over-denture
4. Attachment retained over-denture

16. Immediate overdenture
 Constructed prior to preparation of abutment teeth &
ready for insertion after preparation& reduction
 It enhances patient’s ability & adaptability to wear
dentures

17. Interim overdenture
 Used for patients in transition or preparation phase
until permanent overdenture constructed
 Patient old partial denture can be modified & used by
extending the denture & add new artificial teeth using
self cure acrylic resin

18. Definitive over-denture
 Conventional complete over-denture constructed over
1 or more abutment teeth
 Could be made entirely of acrylic resin or in
conjunction with metal bases

19. Attachment retained over-denture
 Constructed with an incorporated attachment to
improve retention
 More expensive & more time for construction
 Indicated for patient with good oral hygiene & low
caries index
 The abutment teeth should have good periodontal
condition & adequate bone support

20. Types of Attachments
a) Rigid attachment
Doesn’t allow movement of denture base
Provide adequate retention
May induce more torque on abutment
b) Resilient attachment
Allows some control of movements.
Induces less torque on abutments.

21. Over-Denture Attachment
could be in the form of:
 1- Stud Attachments.
 2- Bar attachments.
 3 Magnetic Attachments.

22. 1- Stud attachment
 Consists of 2 parts
The stud usually attached to metal coping cemented
over prepared abutment
Housing embedded in the fitting surface of overdenture

23. 1- Stud attachment
 Extra-Radicular : The stud is attached to the metal
coping cemented over the prepared abutment, while
the housing is embedded in the fitting surface of the
denture. e.g : Ceka , Rotherman, Gerber

24. 1- Stud attachment
B- Intra-Radicular: The stud is attached to the fitting
surface of the denture and the housing is incorporated
in the abutment. e.g : Zest Anchor
 eg

25. 2-Bar attachment
 A bar contoured to connect abutment teeth together ,
run parallel & overlie residual ridge
 Provide support & retention for overdenture & splint
abutment teeth
 Bars may be in form of preformed metal or plastic

26. A- Bar units
 Rigidly fixed to copings, don’t allow any movement
between bar & sleeve
 Transmits occlusal stresses totally to abutments “tooth
born”

27. B- Bar joints
 Resilient attachments allowing movement between
bar & sleeve
 Support provided by both residual ridge & abutment
teeth “tooth tissue born”

28. 3- magnetic attachments
 Small, strong mini magnets
 One of poles cemented in a prepared cavity in
endodontically treated abutment & the other attached
to denture base