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.
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
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
8.
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
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.
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