Complete Dentures Opposed by Natural Teeth Flashcards
3 problems of natural teeth occluding onto edentulous ridge?
- Trauma
- Increased resorption (especially in anterior/ premaxilla region).
- Lack of stability of dentures.
- Uneven occlusal plane and thus inability of achieving balanced occlusion.
- Inadequate or excessive FWS.
- Difficulty in recording jaw relationship.
- Challenges with tooth position of denture and thus compromised esthetics.
- Drifted teeth can alter OJ and OB.
- Tooth wear of denture teeth.
What will worn natural teeth result in?
Increased FWS.
What will over erupted natural teeth result in?
Decreased FWS.
What will occur if a balanced occlusion between edentulous ridge (complete denture) and natural opposing teeth is not achieved?
- Lack of balance will cause denture to TIP.
- Excess LATERAL forces on the ridge and thus INCREASED RIDGE RESORPTION.
What is combination syndrome (3 consequences)?
Lower natural anterior teeth occlude against edentulous upper ridge leading to resorption of the anterior part of the ridge + overgrowth of the tuberosities.
Also geratly compromises the stability of the denture.
2 consequences of trauma to the maxillary denture bearing area by lower natural teeth?
- Soft tissue damage (ulceration and discomfort)
- Alveolar resorption and fibrous tissue replacement of bone (flabby ridge, fibrous ridge, combination syndrome).
2 disadvantages of a flabby/ fibrous ridge?
- Tissue displacement (underneath denture and when impression is taken).
- Tipping of prosthesis.
How can we reduce the trauma to the maxillary denture bearing area (2 ways)?
- MAXIMIZE COVERAGE OF DENTURE BEARING AREA with prosthesis
- Ensure the prosthesis covers the primary load bearing sites.
How can an impression of a fibrous ridge that is NOT severe be taken?
Impression can be taken with special tray with perforations anteriorly.
Record a MUCOSTATIC impression of the tissues (shape of tissues at rest).
How can an impression of a fibrous ridge that is SEVERE be taken?
Two stage silicone impression:
- Use tray with a window anteriorly.
1. First stage impression with putty.
2. Cut away any excess putty that has gone around the fibrous ridge area.
3. Inject the light bodied material around the fibrous ridge (mucostatic situation).
How do we ensure the impression is fully extended/ correct shape?
BORDER MOLD.
What can be done to help with combination syndrome?
- Construct a lower partial denture (especially if Kennedy I) to prevent the upper denture tilting.
What border shape is desired for impressions? What is not desired?
- Rounded borders.
- NOT knife edge.
Would you construct a lower partial denture for a patient with complete upper denture and only lower anterior?
Yes, would greatly help prevent upper denture tipping.
3 advantages of overdenture abutments?
- Help support the denture.
- Maintain alveolar bone in those areas (much less likelihood for resorption).
- Optimize the loading of the denture bearing area.