What Is an Overdenture
A complete denture
that is supported and often
retained by the underlying
teeth or implants and tissue
Abutment teeth or implants
may or may not
be connected to the denture
via attachments
Bars
Studs
Load bearing
Magnets
Copings
Implants
Overdenture Attachments
Teeth
Extraradicular
Combinations
Posts
Non-Load-bearing
Intraradicular
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Overdenture Attachments
Radicular:
Bars:
• Extraradicular
• Bar joints
• Bar units
Studs, magnets,
ERA
• Intraradicular
Zaag, Zest,
Sterns
root
anchor
Round
Ovoid
Square
Rectangular
Objectives of the Program
• Understand how overdentures preserve
hard and soft tissue
• Maintain proprioception
• Understand the function of overdenture
attachments and simplify attachment
selection
• Increasing crown/root ratios to preserve
abutments
• Hygiene maintenance
Carlson and Persson, Odontologist Revy, Sweeden 1967
Anterior mandible
“average bone loss first year after extractions was 4mm”
Tallgren, JPD,1972
“Bone loss continues for at least 25 years”
Dentures vs Overdentures
• Natural
dentition
Chewing
90%
Efficiency
• Complete dentures
59%
• Overdentures
79%
Rissin and House, JPD, 1978
Indications for Overdentures
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Periodontal disease
Few remaining teeth
Insufficient crown/root ratios
Vertical space
Favorable path of insertion
Retention
Advantages of
Overdentures
• Maintenance of bone height around teeth by
preserving roots
• Attenuates resorption patterns of alveolar
ridges
• Gentler to the tissues
• Increases crown/root ratios
• Psychological security
• Enhanced speaking ability
• Maintains Proprioception
Disadvantages of Overdentures
• Esthetic Considerations –
Bulkiness
• Root canal therapy
• Increase space requirements:
-interarch
-interocclusal
• Increase costs
Crown / Root Ratios
Attachment Retained
Overdentures
All the advantages of Overdentures
PLUS
•Superior aesthetics
•Increases proprioception
•Stability and comfort
•Mechanical retention
•Rigidity or resiliency
•Support
•Increased psychological security
and patient acceptance
Overdentures
Attachment Considerations
Load Bearing
Solid / Rigid
• Transfers stress towards the retained
roots or implants and away from the ridge
• No vertical resiliency, some hinge or
rotational resiliency
• Shares the load of occlusion with the
mucosal surface
Magnets, Flexi ball, Dalbo Rotex, Bars
Overdentures
Attachment Considerations
Non- Load Bearing
Resilient
• Transfers stress away from the
retained roots or implants and towards
the tissue
• Vertical resiliency
• Selected frequently
Dalla Bona, Rotherman, Ceka, Uni Anchor, OSO,
ORS, ERA, Bars
Overdenture Evaluation
Partial Denture
Present
• Tooth position
• Occlusion
• Mount casts to vertical
dimension
No Partial Denture
• Mount cast to vertical
dimension
• Diagnostic denture wax
up – reestablish
occlusion
• Silicone matrix for
space evaluation
Direct Placement
• Male or female premanufactured attachment
is cemented into root
• Denture is made and inserted
• Corresponding male or female attachment is
inserted in root
• Attachment is picked up directly in the
overdenture with cold cure acrylic
Placed by Dentist
Indirect Placement
• Male or female attachment is cemented
into root or may need to be cast onto
coping
• Corresponding male or female transfer
analog is inserted into root attachment
• Transfer impression is taken and models
are poured with transfer in place
• Laboratory processes denture with
corresponding attachment in place
Placed by Laboratory
Proceedures To Follow
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5 mm or more root remaining in bone
Stable perio
Mount study models – evaluate space required
Select OD attachment – obtain reference manuals
Begin denture proceedings
Root canal therapy
Decoronate roots, extractions, insert temporary
denture – reline – allow time for healing
• Prep tooth for attachment and cement attachment
• Insert denture, make adjustments, post placement
reline
• Pick up male attachment in denture