5 - 3/6: The Single Denture Flashcards
What is the most common situation that a single denture is needed?
- maxillary arch is edentulous
- mandibular arch has natural/restored teeth
What do natural teeth generate against opposing dentures?
Greater chewing force
Natural teeth do/do not move in function as denture does
Do not
What puts natural teeth far from optimal positions?
Drifting/tilting
What is centripetal resorption?
!!!!!!
Routine resorption pattern following extraction of teeth results in a smaller maxilla when compared to denture arch
- maxilla resorbs UP and INWARD
When is a horizontal arch discrepancy created?
When the maxillary arch narrows and becomes shorter in A-P direction
What can a crossbite be required for?
Direct occlusal forces to the bearing area
What is the combination syndrome?
Maxillary CD opposed by mandibular anterior natural teeth
What things make up the combination syndrome?
- maxillary ant tissue mobile/hyperplasia
- inflammatory palatal hyperplasia (IPH)
- maxillary tuberosities enlarged
- mandibular posterior bone resorption
- mandibular anterior teeth supraerupted
What is the curve of monson?
Combination of curve of Spee and curve of Wilson
What planes does the curve of monson include?
Coronal and sagittal planes
Is the curve of monson concave or convex for the mandibular arch?
Concave
Is the curve of monson concave or convex for the maxillary arch?
Convex
What does the curve of monson form in centric occlusion?
Segment of a sphere of 4 inches radius with the center of the sphere at the glabella
What 3 R’s should be considered when referring to the occlusal plane?
Reduce, restore, or remove
What is occlusion?
Reciprocal arrangement of elevations and depressions
Biting force of natural dentition is approx ______ times that of the denture wearers
5 times
What components make up the natural/edentulous mandible?
- discuss the likely poor outcome
- resilient liner in mandibular denture
- osseointegrated implants in mandible
In regards to alveolar resorption, the mandibular anterior resorbs approx _____ times as fast as maxillary anterior
4 times
What does rapid bone loss emphasize?
“preventative prosthodontics”
The need for any procedure which will slow the bone loss
What did Crum RJ and rooney GE study show?
Retaining mandibular canines for overdentures preserved alveolar bone
What are advantages of overdentures?
- denture support is increased and soft tissue trauma is decreased
- stability of denture is increased
- maintenance of periodontal proprioception improves chewing efficiency
- physiological benefit to patient
- resitual ridge integrity: improved stress distribution
- stability and retention
- patient’s perception of preserved natural teeth
- viable and simple alternate technique to CD
- application is virtually unlimited
When should you consdier overdentures?
- when a conventional denture would have poor prognosis
- when opposing an arch of natural teeth
- when “combination syndrome” is a factor
What are disadvantages of overdentures?
- cost: more $ than conventional denture- RCT, copings
- denture is bulkier in some areas
- denture more subject to fracture
- caries/perio sequelae
- likely time dependent transition to CD, depends on patient’s oral hygeine and nature of selected abutments
- age related inability to follow proper hygeine
- presence of refractory periodontal disease
- caries
- frequent recall appointments, expense
-available interarch space - weakness in acrylic denture base
- cast coping: increases lab procedures/expenses
What needs to be considered when selecting abutment teeth?
- Periodontal and mobility status (horizontal bone loss)
- Abutment location (canines/premolars) - at least one tooth per quadrant, no adjacent teeth
- Endodontic and prosthodontic status
What are the endodontic/prosthodontic statuses?
- anteriors easy for endo
- in cases of calcification- endo can be avoided
- crowns can be modified - sealant/fluoride t/t use of copings, composite/alloyrestorations retention attachment system
What is recommended for mot overdenture abutments?
Root canal treatment
What doesn’t eliminate a tooth for use as an abutment?
Tooth mobility
What is improved when crown is reduced on the tooth?
Crown/root ratio (mobility lessened)
What teeth are most frequently selected for abutments?
Canines
- have large roots
- amenable to RCT
- strategic location at corner of arches
What are problems with abutments?
Abutment failure- caries or periodontal
Denture fracture - metal base
What are causes for abutment loss?
Periodontal disease, caries, endodontic complications
What causes gingivitis around abutment?
- Movement of denture base
- Poor oral hygeine
- Excess space in prosthesis (dead space)
What are types of restorations used for abutments?
Amalgam
Cast gold copings
Describe the locator root attachment?
A supra-radicular design that gives you the choice of a straight post and two angles (10 and 20 degrees) to accomodate divergent roots and a special cast to version
What is required for an implant overdenture?
Surgical guide
What are implant bars designed for?
Hygeine
What does it mean if an implant is retained and supported?
No pressure on the ridge
