Complete Dentures Opposed by Natural Teeth Flashcards
What can high levels of force from lower teeth developed against edentulous maxillary ridge result in?
Trauma and instability of denture
What can trauma to maxillary denture bearing area result in?
Soft tissue damage
-> ulceration
-> damage to mucous membranes
Alveolar bone resorption and replacement with fibrous tissue
-> flabby ridge (you will be able to feel lack of bone and that ridge can be displaced)
What does a flabby ridge result in?
Poor support (tipping)
Poor retention
Poor stability in lateral and oblique directions
What are the features of Combination syndrome?
Bone loss from the anterior part of the maxillary ridge
Hypertrophy of the tuberosities
Papillary hyperplasia in the hard palate
Extrusion of the mandibular anterior teeth
-> Bone loss under the opposing denture base
What is controversial about combination syndrome?
May not exist- not many people have all the features required to be combination syndrome (also doesn’t qualify as a syndrome)
How is trauma to maxillary denture bearing area reduced?
Maximise coverage of the denture bearing
area by the prosthesis (spreads load)
Ensure prosthesis covers the primary load
bearing sites (alveolar ridge)
Why can it be useful to keep some retained roots when removing teeth for complete upper denture?
They can serve as ‘implants’ for an overdenture
-> roots have PDL remaining so they resist load and reduce ridge resorption
What can be done to improve stability of complete maxillary denture opposing natural teeth?
Optimise border seal- get periphery of denture to depth of sulcus
-> achieved through good primaries and good border moulding at master stage
Post dam- extending to vibrating line (just anterior to palatine fovea)
Balance in centric occlusion
What can be done if patient feels post dam is too far back?
Have second post dam further forward as a back up
What can happen if patient has complete upper denture and SDA in the lower? What can be done to fix this?
Tipping of denture due to force anterior causing denture to drop at the back resulting in breaking of border seal
-> occurs when eating (patient may need to use a lot of fixative)
Lower bilateral free end saddle denture can prevent this (but not all patients can tolerate- warn about compromised stability )
Why may lower bounded saddles need to be replaced with partials when occluding against complete upper denture?
Gives more even occlusal plane
-> increased stability of maxillary denture
How can a deep overbite occluding against an upper complete denture be managed?
To prevent tipping effect:
Cut away length of lowers (careful with sensitivity)
Re-site upper denture further up (issue with patients not showing anything in uppers)
-> Combination may be best compromise- important to spend time perfecting this in wax trial stage
What is the issue with periodontal disease in lower teeth opposing complete upper denture?
Can cause stepped (irregular) occlusion
-> not conducive to stable upper (cannot cope with eccentric excursions of mandible as points of contact cause destabilisation)
Why are complete upper and lower dentures more stable than complete opposing natural teeth?
Balanced contacts present on both sides on excursive movements
When denture occludes against natural teeth during lateral excursions the contacts are not balanced and this causes tilting (especially if uneven natural occlusion)
What can be done to fix irregular occlusal plane on natural teeth opposing denture?
No adjustments- requires accurate registration and collaboration with technician
Minimal localised occlusal grinding
Radical occlusal adjustment
Extraction of teeth- if no chance of achieving balanced occlusion due to tooth tilt
Overlay appliances OR composite build ups using stents
