1. What Is an Overdenture A complete denture that is supported and often
retained by the underlying
teeth or implants and tissue

2. Abutment teeth or implants may or may not be connected to the denture
via attachments

3. Overdenture Attachments
Bars
Copings
Studs
Magnets
Implants
Load bearing
Overdenture Attachments
Posts
Teeth
Non-Load-bearing
Extraradicular
Intraradicular
Combinations
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4. Overdenture Attachments
Radicular:
Extraradicular
Studs, magnets, ERA
Intraradicular
Zaag, Zest, Sterns root anchor
Bars:
Bar joints
Bar units
Round
Ovoid
Square
Rectangular

5. 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

6. Anterior mandible Carlson and Persson, Odontologist Revy, Sweeden 1967
“average bone loss first year after extractions was 4mm”
Tallgren, JPD,1972
“Bone loss continues for at least 25 years”

7. Dentures vs Overdentures Chewing Efficiency
Natural dentition
Complete dentures
Overdentures
90%
59%
79%
Rissin and House, JPD, 1978

8. Indications for Overdentures
Periodontal disease
Few remaining teeth
Insufficient crown/root ratios
Vertical space
Favorable path of insertion
Retention

9. 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

10. Disadvantages of Overdentures
Esthetic Considerations – Bulkiness
Root canal therapy
Increase space requirements:
-interarch
-interocclusal
Increase costs

11. Crown / Root Ratios

12. Attachment Retained Overdentures
All the advantages of Overdentures
PLUS
Superior aesthetics
Increases proprioception
Stability and comfort
Rigidity or resiliency
Mechanical retention
Support
Increased psychological security and patient acceptance

13. 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

14. 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

15. 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

16. Direct Placement Placed by Dentist
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

17. Indirect Placement Placed by Laboratory
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

18. Proceedures To Follow 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