System of design Flashcards
What are alternative treatments to partial dentures
No active treatment
Fixed prostheses
* conventional
* resin-bonded
Implants retained prostheses
Why do clinicians design the denture instead of lab techs
They have seen the patient
They know first hand the condition of the teeth and surrounding periodontium
They can assess occlusion
They can give clear cost information (GDC standard 2.4)
What are the key principles of partial denture design
Replace lost teeth & tissues, restoring function, speech, & aesthetics
Minimize damage to adjacent teeth, restorations & tissues
Designed with periodontal health in mind
What is the sysematic stepwise approach to designing partial dentures
- Case Assessment
- Classification of support for each saddle (Mucosa/Tooth/Combination)
2a. Choose denture base material (Acrylic or Cobalt/Chromium)
2b. Connect saddles together (Connectors) - Choose the path of insertion & delineate undercuts (Surveying)
- Resistance of movement away from the teeth (Retention)
- Indirect retention
- Resistance of movement towards the teeth & tissues (Support)
- Resistance to horizontal movement (Bracing/Reciprocation)
- Simplification
What is a saddle
An area of oral mucosa where teeth are being replaced
What is class 1 of craddock
Tooth borne
What does class 4 indicate in craddock
Implant borne
What classification would a saddle supported by implant and mucosa fall under
Class 5 (V)
What is class 3 (III) craddock
tooth and mucosa borne saddle
How is kennedy used to classify a Single bounded saddle not crossing the midline
Class 3
What saddle does a patient with no anterior teeth need
Class IV Single bounded saddle
crossing the midline
When more than one edentulous saddle is present which is used to define the main kennedy class
The most posterior saddle
Why do we survery casts
Helps us choose retentive elements
(clasps)
Path of insertion (& removal) of
denture
What are methods of retention
Soft tissue undercuts
Adhesion (maxillary plates)
Friction
Path of insertion
Precision attachments / implants
What is indirect retention
The effect achieved by one or more indirect retainers (rests)that reduces the tendency for a denture base to move in an occlusal direction or rotate about the fulcrum line
What are the types of rests
Occlusal rests
Cingulum rests
(Onlays)
What does a denture with inadequate support risk
denture sinks into the tissues
and traumatizes them
What does the reciprocal arm of a clasp do
Prevents tooth moving
What is the job of a clasps retentive arm
Engages undercut
Why is simplification of partial denture design important
Complex designs have complex failure/problems
Patient preference
To meet the demands of economic viability of working within health services
What is the system of design
Saddle(s)
Support
Retention
Indirect retention
Bracing
Connectors
Review & simplify
What support does a free end saddle have
Tooth and mucosa (class 3)
What are some methods of retention
Clasps
Soft tissue undercuts
Adhesion (maxillary plates)
Friction
Path of insertion
Precision attachments / implants
What is a reciprication arm
Stops the tooth moving under the bracing arm which is applying force to the tooth
What are some major connectors
Upper arch
-horse shoe
-ring
-strap
-Plate PMMA/CoCr
Lower arch
-CoCr bars
-Plates pmma cocr (space for tongue)
What are the choices of saddles
Flanged
Gum-fitted/open face
