Principles of partial denture design Flashcards
What are 5 things to think about with RPD?
indications
complexity
design
preparations
maintenance
List indications for RDP?
Patient preference
Need for flange
Limited dentition and limited bone
Need for future additions/modifications
2 or more edentulpus saddles
Use of teeth as over denture abutments
Interim solution
What guide should you refer to for assessment of complexity of RDP?
Charlotte Stilwell et al
What are the principles of design for o-Cr dentures?
Must be hygienic
Provide good support
Make sure the connector is rigid
Keep it simple
How do you ensure the co-cr is hygienic?
Avoid gingival coverage - otherwise can be plaque retentive
Easy for patient to clean and maintain
What gap should be between the gingival margin and the denture?
3 mm
Why does the denture need to be rigid?
Distribute evenly the load of the denture
What are the 8 steps to design co-cr dentures?
- Saddles
- Support
- Retention
- Bracing/reciprocation
- Indirect retention
- Guide planes
- Connectors
- Review principles of design
What colour do you draw saddles in co-cr denture design?
Yellow
What colour are do you draw the support in co-cr design?
Red
What colour are do you draw the Retention in co-cr design?
Green
What colour are do you draw the Bracing/reciprocation in co-cr design?
Blue
What colour are do you draw the Components apart from saddles, support, retention and bracing/reciprocation?
Black
What is the flange?
When designing the saddle in a free-end-saddle denture, what needs to be decided?
Flange design to utilise undercuts? - retention
Avoid under cuts, if too deep or in wrong place
Saddle design must be hygienic - avoid creating stagnant areas around abundant teeth
Extension of denture base in saddle area
Usually required to cover maximum possible area to spread occlusal load as wide as possible
Minimum load/unit area - enhance possibility of patient comfort during use
Decide on shape of polished surface
Placement of teeth in the correct neutral space
Appropriate shape and design can assist stability and resist displacement
Why do you sometimes avoid undercuts when it comes to saddle design?
Can resist insertion of appliance or cause trauma to underlying tissues
What can be incorporated into saddle areas?
Appropriate support and retentive devices (clasps, rests)
What question do you alway ask when it come to saddles?
Do we need to fill this edentulous space
What areas supply support to denture - bounded saddles?
Nearest surface of each abutment tooth
What areas supply support for free-end saddles?
Mesial side of the abutment tooth
For a bounded saddle, what allows retention of the denture?
Retention on both abutment teeth
When can a saddle not have a slap on at least one abutment tooth?
Aesthetics in the way
For a free-end saddle, what allows retention?
On the abundant tooth on the saddle
Why do you not add clasps anteriorly?
Because of the rotation about the clasp axis, there is no point in adding further clasps more anteriorly to this.
They will rotate down and not engage when pilling (sticky food)
What happens if you have too much much or undercut in the wrong place?
We can re-shape the tooth by cutting a guide plane or adding composite
How do you add a bubosity in the lab?
Add wax to area
In clinic, etch and bond tooth for composite
What do you check for bracing/reciprocation?
Check resistance to lateral and anterior/posterior movement
Flanges extended properly to aid with bracing
What do you check reciprocation?
Check reciprocation of each retentive clasp arm
Consider using guide places for reciprocation in vulnerable teeth
What is indirect retention?
Resistantce to the rotational displacement in a tooth that supports denture
How can you combat rotation of denture?
Adding rest seats
Aka indirect retention
What are guide planes?
two or more vertically parallel surfaces on abutment teeth and/or fixed dental prostheses oriented to contribute to the direction of the path of placement of RPDs.
List the purposes of guide planes?
For single path of insertion
For reciprocation (on vulnerable teeth)
For indirect retention
To create a path of insertion radically different from path of displacement
To prevent distortion of co-cr clasp arms
List the 6 maxillary connectors?
Anterior palatal bar
Mid palatal bar
Posterior palatal bar
Horse shoe
Palatal plate
Ring
List the 5 mandibular connectors?
Lingual bar
Sublingual bar
Lingual plate
Dental bar
Buccal bar
