Clinical Stages of RPD (1 and 2) Flashcards
(109 cards)
1
Q
clinical stages for RPD
A
VISIT 1: Assessment & Primary Impressions
VISIT 2: Master Impressions
VISIT 3: Framework Trial (+/- record occlusion)
VISIT 4: Tooth Trial
VISIT 5: Delivery (Fit)
VISIT 6: Review
2
Q
visit 1
A
Assessment & Primary Impressions
3
Q
visit 2
A
Master Impressions
4
Q
visit 3
A
VISIT 3: Framework Trial (+/- record occlusion)
VISIT 4: Tooth Trial
VISIT 5: Delivery (Fit)
VISIT 6: Review
5
Q
visit 4
A
Tooth Trial
6
Q
visit 5
A
Delivery (Fit)
7
Q
visit 6
A
Review
8
Q
visit 1 consists of
A
Examination of Patient and Denture
9
Q
Examination of Patient and Denture in visit 1
A
Remember History and Examination from Lecture 1
Look in the mouth!
- Ridge form
(Displaceable tissue – feel the ridge)
- Free end saddles – no teeth posterior to the saddle
- Bounded saddles- teeth abutments on both sides of saddle
- Undercuts - tooth and soft tissue undercuts
assessment of denture form available on clinics
10
Q
what do you need to wear on all visits
A
PPE
saliva
blood (potentially)
11
Q
what to look for when trying in selected tray
A
Fit all teeth
Fit comfortably in oral cavity
Position of tray handle, important because don’t want to distort any of the soft tissues when place
- Wrong way up will lift sulcus up and distort
12
Q
stock trays
A
perforated with removable handles
edentate or dentate
13
Q
edentate stock trays
A
shallower
14
Q
dentate stock trays
A
greater depth
15
Q
impression material for no free end saddle
A
alginate
16
Q
impression material for free end saddle
A
compound and alginate
17
Q
what material is generally used for primary impressions
A
alginate
depends on clinical situation
18
Q
non elastic impression material
A
impression compound
can be used to modify stock tray to fit better
19
Q
elastic impression material
A
alginate
elastomer
- silicone
- polyether
20
Q
if there is many undercuts what impression material should be avoided
A
non elastic compound
not able to flex which you need to remove impression
21
Q
example of when you would need to use compound
A
free end saddle
- Full extent of impression not captured
- retromolar pads missing
modify stock tray before requesting special tray
22
Q
compound main use
A
Stabilise tray with compound
- prevent rocking when only anterior teeth present
No teeth in compound
- could pull them out if poor perio health
- Use heat and wax knife to remove
place alginate wash over the top
23
Q
should compound impression include teeth
A
no
alginate wash on
24
Q
4 stages of primary impression
A
select stock tray and modify peripheries/fit surface with wax or compound and burrs
apply adhesive and use alginate/compound for impression
border mould needs to be strong
disinfect and place in sealed bag with wet cotton wool/paper
label bad and write instructions to technician
25
why do you need to place impression in a sealed bag with wet cotton wool/paper?
alginate can take water on
| - expand and be inaccurate if no wet wool (crack)
26
what is used for decontamination and disinfection
perform
27
hand articulation
Put casts together and obvious how they meet
- Sufficient to be transferred to technician
You don’t need to record the occlusion, don’t need a primary record block
- Can go onto master impressions
28
why do we need to record the occlusion
measuring how the teeth meet, the comfortable bite
Look for space to place rest seats when casts on articulator
- Plan for preparation of rests seats if no space available
29
wax wafer
inter-occlusal record
Warm wax the patient bites on
- Used when no free end saddles but occlusion isn’t obvious by hand
Want no space between upper and lower – excess wax will open the bite
30
too much wax used for inter-occlusal record
pin doesn’t lie on table of articulator
Something has happened to the OVD (too much wax or articulating paste)
31
what type of casts cannot be hand articulated
free end saddles
need a primary record block from the lab
32
reasons for primary record blocks
You can’t obviously see how the teeth meet
Use to mount the casts accurately
Look for space to place rest seats and baseplate
Plan for preparation of rests seats if no space available
- Facilitating the design
(How to obtain information needed for denture design and how to plan for it (rests))
33
how to bond sides of a free end saddle together
wax or silicone registration paste
| squashed in between arches
34
what can be an additional visit
if a primary record block is required as there is not enough teeth to hand articulate (free ed saddle)
35
instructions to the technician if hand articulated
Pour primary cast
Special tray with spacer
- 1-2 sheets of wax depends on master impression material with handles/ finger rests etc.
36
instructions to the technician if non hand articulated
Pour primary cast
Special tray with spacer
- 1-2 sheets of wax depends on master impression material with handles/ finger rests etc.
Construct primary record block for a preliminary jaw registration
- Base can be wax, shellac or light cure acrylic
37
what needs done before visit 2
Design the denture – cannot take master impression before completing this
38
how to design the denture
Survey to decide the path of insertion
Survey to decide undercuts etc – know where clasps to be placed
Do you need to modify teeth to produce rest seats, guide planes and undercuts (Dr Cross lecture)
Draw the design on the laboratory work card and get signed off by clinician
39
4 key points to remember in denture design
The denture design must conform to the patients occlusion unless you are planning to change
If there is no inter-occlusal clearance for a rest either make space by cutting a rest seat or do not place a rest.
If you don’t make space the occlusion will not be correct.
- Will bother patient – pressure on rest will lead to it breaking off
If there is no space the rest will simply open the bite.
40
first things to do on visit 2
try in special tray
41
special tray
Bespoke custom tray made to primary impression - Needs to be accurate
42
3 things to check with the special tray
overextended
under extended
Handles shouldn’t disrupt soft tissue - up from lip
43
overextended special tray modification
Trim peripheries if overextended with slow speed
44
under-extended special tray modification
Modify peripheries with greenstick and fit surface for free end edentulous saddles (under extended)
45
4 impression material options
Poly vinyl Siloxane (medium bodied silicone)
Polyether
Alginate
Impression Compound (modify the tray)
Use the specific tray adhesive for the material you are going to use,
specify to nurse the one you wish to use
46
medium bodied silicone (PVS) properties
Brand name: Extrude
3 bits - mixed together coming out of nozzle
Do not use a lot - enough to cover surfaces wanted to record
```
Shallow spacing (1-1.5mm)
- Don’t want excess - cannot swallow as doesn’t biodegrade, gets stuck in GIT
```
47
polyether properties
Brand name: Impregum
Addition polyether
Mixes in nozzle
Wipe of excess in tray
Be careful in undercuts
- Periodontal disease could get tray stuck
Very accurate
48
alginate properties
Well mixed (smooth)
Poured up as soon as possible
Good if undercuts present
Careful for air blows – will compromise accuracy of impression and therefore casts
49
why do you need to cover alginate with damp cotton wool and cast ASAP
Cover with damp cotton wool seal in bag to prevent alginate drying out
Needs to be cast as soon as possible to avoid inaccuracies developing as a result of the dimensional instability of alginate
50
why are the master impressions important stage
everything that follows will not be accurate
51
master impression stages
try in special tray and trim peripheries if overextended
modify peripheries with greenstick and fit surface for free end saddles
apply adhesive and use alginate/polyether/PVS for impression.
- Border mould needs to be strong
disinfect place in sealed bad and write instructions to technician
52
do you need water in sealed bag for polyether or silicone material
no
| dimensionally stable
53
cobalt chrome instructions to technician after master impressions
Pour model in improved stone
Construct chrome framework per design
- Clear design signed by clinician
Remember to prepare occlusal rests/guide planes before taking impression
54
acrylic instructions to technician after master impression
Pour model in stone
Construct record block with shellac base
55
before visit 3 you have already
Check spaces for rests
Designed agreed
Measured depths into sulcus, undercuts for clasps
RPI planned for free end saddle
56
6 points to check in the framework trial in visit 3
Does it fit the cast?
- No then won’t fit the patient
Does it seat correctly in the mouth?
Is the cast damaged?
- Undercut too great (tooth came off in process)
- Difficulty inserting and removing – need to alter path of insertion
Is the framework interfering with occlusion?
- Interfering with bite, rocking, does it move
Adjust chairside
- Wear appropriate PPE (special mask for chrome adjustments)
- Use adams pliers for clasps
Adjust in the laboratory
57
4 key checks of framework before registering the occlusion
Does it fit the cast?
Does it seat correctly in the mouth?
Is the cast damaged?
Is the framework interfering with occlusion?
58
if you have record block on the framework already then
there is no separate recording of the occlusion
59
5 reasons why we need to record the occlusion
To help design the denture
To help the technician set-up the teeth
(To ensure the denture is stable and is not dislodged in function)
Patient comfort
Ensuring loading forces applied correctly to teeth
60
conformist approach to occlusion
Keeping the occlusion the same as it currently is
Need to know the position of the teeth in relation to each other. Keep in comfort
61
re-organised approach to occlusion
```
Altering the occlusion
- Tooth wear
- Not enough teeth to meet
Different OVD
Not yet, only BDS4 and BDS5
```
62
aim of recording the occlusion at visit
Establish
- Inter-occlusal relationship to articulate casts (decide where teeth are going to be)
- Occlusal vertical dimension (OVD)
- Tooth shade and mould
extended edentulous spaces
- buccal/labial contours of wax record block
- lip support
- Incisal plane
- Posterior plane
63
wax record block recording process
2 lumps of wax on teeth technician knows where to teeth are
- Know what you are aiming for
Similar to primary impression but wanted on mounted casts
64
4 points you are aiming for when recording the occlusion to tell the technician
- where you want the artificial teeth to be positioned
- their shade
- mould together
- information on how the teeth occlude
65
if there is no index teeth then what do you need to measure
the OVD and FWS
66
OVD
occlusal vertical dimension
67
at rest distance between teeth
2-3mm
68
free way space is
the difference between the at rest measurement and the measurement when teeth are biting
- use willis gauge
69
what do you use for initial setting point for OVD
old dentures
70
equipment you will need to register the occlusion
- Bunsen burner and wax knife
| - Hot plate
71
why do we need to trim the registration blocks
as they are average sizes so will be bulky and they need to stay in place
72
what will an overextension into the buccal sulcus mean
it will drop/displace
| - displace with cheek movements
73
how to make adjustments to wax registration blocks
Use the wax knife and hot plate/spatula to make adjustments
- Contour where you want teeth
adjust upper rim first
may need to adjust labially/buccally
if there is too much wax in tongue space - reduce
74
too much wax in tongue space of record block
reduce
Lingual pouch area - lift tongue does it dislodge
75
4 points you need for prescribing the position of anterior teeth
1. Make sure index teeth in occlusion – bite together
2. Mark centreline
3. Correct incisal plane
4. Correct antero-posterior position
Give technician as much information as possible
76
8 reference points for recording the occlusion on registration blocks
Teeth present
Dento-facial midline
Inter-pupillary line
Ala-tragus line
Curvature of lower lip
Smile line
Gingival margins of existing anterior teeth
Previous dentures
77
inter-pupillary line
imaginary horizontal line drawn between the centres of the pupils of the eyes
78
ala-tragus line
line from the lower border of the ala of the nose to the upper border of the tragus of the ear
79
anterior plane of the rim should be parallel to what?
inter-pupillary line
80
what should the centre line coincide with
the midline
81
what should the posterior plane coincide with
the alar-tragal line
82
2 factors in tooth selection
shade
mould
83
shade determination for teeth
- existing teeth
- previous denture
- patient preference
84
mould determination for teeth
- existing teeth
- previous denture
- measure
85
how to decide how to arrange the teeth
Talk to patient how they wish the teeth arranged
| - May want replicated crooked teeth
86
what to do after recording the occlusion on the wax and making reference points
decontaminate and disinfect
87
articulator instructions for the technician
what do you want the cast to be mounted on
Plane line / hinge
- Simple hinge is very straight forward, use when only a couple of teeth missing
Average value
- Most commonly used
Semi - adjustable
88
record block on framework instructions for the technician
Construct wax record blocks on chrome framework
| Additional visit required
89
visit before tooth trial (to prepare)
Received framework back with record block on
- Check fit, damaged, check in patient
Articulate casts to registration
Select teeth for wax trial (shade and mould provided)
90
3 main reference points for jaw registration (always check)
Exiting teeth
Midline of face
Interpupillary line
91
what does the pin of the articulator not being on the table indicate
Check occlusion in mouth
| - Rest seat in bite?
92
4 points to check in framework tooth trial
Framework Fit
Occlusion - check bite OK. Registration not right go back to wax bite??
Aesthetics
Extension
93
what is the framework tooth trial purpose
Dress rehearsal for the finished denture- patient must be happy before taking to finish in acrylic
Everything needs to be correct or re-trial
94
what can you do if there is issues in the framework tooth trial
Can adjust teeth by heating up wax and lowering bite
- Can do a retrial with different shade and mould
describe the changes needed to the technician
Need to get patient agreement before moving on
95
after the tooth trial
decontaminate and disinfect
96
finish instructions to the technician
Please take to finish in acrylic (no more wax)
97
if the denture doesn't come on the cast what does this indicate?
may not fit
Small dimensional changes in acrylic
- Could effect fit
98
6 things to check on the articulator before placing the denture in the patient
Pin on table – seats properly
Nothing interfering with bite
As prescribed
Examine dentures for roughness/ blebs
- Very sharp in mouth
Undercuts- are any teeth on the cast broken?
Does the occlusion look correct
99
4 things to check when patient tries denture
Stability
- Does it rock?
Support
- Are rests/flanges seating accurately
Retention
- Adjust clasps with Adams pliers
Aesthetics
- Carry out above checks first, last thing you do is show the patient
100
what to do if the denture doesn't fit in the patient
don't force it in if doesn't seat properly
Undercuts- what goes in does not always come out, material may not be elastic enough to flex in and out
101
how to check the occlusion
Check with articulating paper for heavy/early deflective contacts (premature early contacts)
teeth meet in the prescribed occlusal scheme per the wax up
102
small change to occlusion requried
adjust with acrylic bur at chair-side
103
large change to occlusion required
may require removal of teeth and re-set in wax (lab on level 6)
Polish acrylic after adjusting with a bur
104
instructions to give to patient on denture delivery
Insertion / removal elderly patients may struggle
Coping with new dentures like breaking in shoes, perseverance to adjust, metal and plastic nothing like natural tissues,
- Brain needs to recognise change in mouth
0 Couple of months for neuromuscular contrail for free end saddles
Pain
Denture cleansing
Speech
Eating
Take out at night
- Denture stomatitis. Can progress to pneumonia
Refer to clinic patient information leaflet
105
what do dentures cause greater production of in the oral cavity
more saliva
affect speech, eating, denture cleansing
106
what occurs in the review visit
history
examination
adjustments
can be difficult
- Any sore bits - wear for a few days before so they can be seen and assessed (don't avoid wearing)
107
process of recording the occlusion
wax record blocks are easy to adjust
increase veritcal dimension
- creates gap between the arches
heat up wax to adjust
- carve it with a wax knife
reduce height of block to conform with patient bite
- not propping it open
notches cut on wax where teeth are to go
silicone registration paste here to register the teeth
- 2 notches cut in wax
- impressions on wax and bite recorded
avoid excess material which will change bite
start with upper record block
- more aesthetically vital
then work on lower
108
basic process for 2 record blocks
1. Identify index teeth
2. Adjust one block to keep index teeth in occlusion
3. Adjust second block with first one still in to keep index teeth in occlusion
4. Record occlusion
Soften wax or use registration paste to get them to stick together
109
index teeth
teeth that you can reproducibly get bite together, they meet
