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.
Would you construct a lower partial denture for a patient with complete upper denture and lower anterior teeth + a bounded saddle?
Yes, can improve the occlusal contacts/ prevent tipping.
What will happen if the overbite is too great in an upper full lower only anterior teeth present situation? How can this be managed?
Instability and tipping of the upper denture.
- Position of denture teeth (may compromise aesthetics).
- Reduction of the incisal edges of the natural teeth.
Effects of an uneven occlusal plane when providing a denture?
- Uneven occlusal plane –> inability to provide balanced occlusion
- Lack of stability, denture movement and thus discomfort, difficulties eating + loose denture.
What helps ensure that maxillary complete dentures have balanced articulation with lower dentures?
With complete dentures, COMPENSATING CURVES help achieve even contact on both sides.
2 stages when you can ensure complete U and L dentures provide balanced articulation?
- MAINLY During the articulating stage.
- Spot grinding at the finish stage of dentures
What happens during lateral excursions when an upper complete denture and lower natural teeth?
Occlusion no longer balanced, uneven contacts on both sides.
Can lead to TIPPING of the denture.
6 ways to manage an irregular occlusal plane on natural teeth?
- No adjustment
- Minimal localised occlusal grinding.
- Radical occlusal adjustment (ex. crown placement)
- Extraction of teeth
- Overlay appliance
- Implants
When are overlay dentures indicated?
- Usually used when the teeth are WORN and there is sufficient room (tooth wear —> increase of FWS & decrease of OVD)
What is a requirement for overdenture placement?
- Require very good oral hygiene as they form plaque traps.
What are 3 advantages of overdentures?
- Improve aesthetics.
- Help retain alveolar bone.
- Help restore occlusion and thus allow balanced occlusion and articulation with opposing denture.
What happens in the situation where there is upper natural teeth and lower complete denture?
- Same issues as opposite yet MUCH MORE SEVERE.
4 reasons why upper natural teeth and lower complete denture is very severe?
Potential severe trauma to lower ridge due to:
- Excessive occlusal forces.
- Occlusal imbalance.
- Minimal denture base foundation area.
- May lead to accelerated resorption of lower ridge.
3 methods in which an upper natural teeth and lower complete denture situation be managed?
- Soft lining
- Retain roots and provide overdenture
- Implants
2 disadvantages of soft linings?
- Do not last as long as hard acrylic surface.
- More difficult to keep clean.
