Denture choice and design Flashcards
(40 cards)
What is an overdenture/onlay or overlay denture?
Denture used where the natural crown for AB teeth is not complete
What are transitional dentures?
When you want to make a denture but you know some teeth need extracting within the expected lifetime of the denture
What are immediate dentures and immediate addition dentures?
This is a new denture placed in mouth immediately after a tooth is extracted
Immediate addition - where a patients existing denture has an extra tooth added and is fitted imm after extraction
What are temporary dentures
A denture used for a short time before permanent denture is made
What is a diagnostic denture
tests if patient can tolerate something new (commonly a change in kaw relationship or change in tooth position) or to see if pt can tolerate a denture at all
What are obturators
a denture that has an extra piece of acrylic that blocks a hole in the palate (specialist skills needed)
2 materials that dentures are made of
Acrylic and CoCr
What factors do you need to consider when choosing which type of denture?
Time available - acrylics quicker (can make them fit if impression incorrect)
Yours and technicians skills - CoCr more difficult
Costs - to you and pt (time and money)
Pts choice and expectations - pts preferences guided by dentist
Pts prev denture experience - which denture has worked for them before, how is current denture regarding support, retention, stability
Outline of steps for CoCr RPD design
- Survey cast - choose/limit POI - consider natural or artificial GPs
- S (saddle areas)
- S (support - tooth and mucosa)
- R (retention - direct and indirect)
- R (reciprocation)
- C (connectors - major and minor)
CHECK ALL CLASPS RECIPROCATED AND EVERYTHING CONNECTS
How can guide planes and POI be utilised when designing dentures?
Choose POI = diff to path of common displacement (right angles to occlusal surface)
Survey cast
Identify favourable and un-favourable undercuts
Identify natural and artificial guide planes
Art GP - flatten contours of AB teeth using burs = parallel sides = limit POI = more retentive, aesthetics of ant teeth (black tri.), function
S - saddle
What is Kennedy Class I
Bilateral free end saddles
S - saddle
What is Kennedy Class II
Unilateral free end saddles
S - saddle
What is Kennedy Class III
Bounded saddles
S - saddle
What is Kennedy Class IV
Anterior bounded saddle that crosses midline
What is a modification in kennedy classification
Main classification is allocated using most posterior saddle and then however many other saddles there are determines the number of modifications
S - support
What are the key features of rests used for support?
Rest on each end of a saddle
Distribute them evenly around the arch - table with 4 legs
Rest on teeth that healthy
Ensure no occlusal interference - enough space and clearance - PREPARATIONS
R - retention (direct)
What is used for direct retention
List the parts of the assembly of this
Clasps
System:
-Rests (occlusal)
-Clasp arm (tapered and thinner at the end)
-Reciprocal arm (same length throughout and thicker)
-Minor connector
What does a reciprocal arm do?
Prevents unwanted tooth mvmt
How do clasps and reciprocal arms work
Sit passive in undercut and terminal third only engages undercut on AB teeth when denture removed as resists movement
Reciprocal arm engages with tooth throughout and does not move
What are the different types of clasps
Occlusally approaching - circumferential
Gingivally approaching - anterior teeth
Ring - (recip wraps buccal to lingual)
Lateral
How do you choose no of clasps and where to place them
One disadvantage
Depends on teeth missing and pattern of tooth loss
Adjacent to the saddles and spread evenly around arch
2 clasps needed - diagonally opposites sides of arch to spread out
Increases risk of caries
R - retention (indirect)
What is indirect retention and what is used
Rests added
Usually for free-end saddles
-Aim to prevent the FW rotating around an axis which is formed across the AB teeth that are clasped
-Denture rests on teeth or mucosa can resists rotation
What are the different types of rests?
Occlusal
Cingulum
R - reciprocation
What can be used to provide reciprocation for clasp assemblies for posterior teeth and what can be used for anterior teeth?
Plate/arm for posterior teeth
Plate with rest/rest only for anterior teeth