Prosthodontics (removable) Flashcards
(150 cards)
1
Q
what is definition of complete dentures?
A
A removable dental prosthesis that replaces the entire dentition and associated structures of the maxilla or mandible
2
Q
list some effects of endentulism?
A
o Loss of masticatory function
o Appearance
o Self esteem
o General health effects
o Quality of life
o Speech
o Ridge resorption
o Soft tissue changes to lip & chin
o Reduction in face height
o Not only do you lose teeth you lose bone and soft tissue
3
Q
describe resorption after extraction of teeth?
A
Occurs rapidly after extraction particularly in 1st six months
Individually variable
May be dependent on pre-extraction status of teeth
Occurs throughout life
4
Q
what are the 2 types of variations in ridge resorption?
A
cawood and howell 3 and 5
5
Q
list some feature a patient will experience from complete dentures?
A
o Inefficient at mastication
o Require good neuro-muscular control
o Stability of a lower complete often compromised by tongue movements
o Appearance/speech can be sub-optimal
6
Q
list some of the main reasons to make a patient endentulous?
A
- caries
- periodontal disease
- severe and debilitating tooth wear
- failing dentitions
- occlusal collapse
- appearance
- head and neck chancer - chemo
- pre chemo
- pre transplant
- pre cardiac surgery
- at patients request
7
Q
what are diff methods of complete denture construction?
A
conventional and replica or both
8
Q
questions to ask pt about their denture history?
A
- No previous denture wearing experience
- Previous denture wearing experience
- What does your patient think?
- Age of dentures?
- Matched set?
- Most recent set worn?
- When 1st denture?
- How many sets dentures?
- Material/soft lining?
- Success or failure?
9
Q
what should you especially look for in intra oral exam?
A
- Support in edentulous areas
- Mouth opening – trismus
- Peri-oral opening
- Support – Resistance of vertical movement of a denture towards the ridge
10
Q
what are some things patient could be suffering from after old denture?
A
- denture stomatitis
- angular chelitis
- dental hyperplasia
11
Q
what do you check during denture examination in mouth?
A
- Occlusal planes: anterior & posterior
- Vertical Height – RVD – OVD = Freeway Space
- Occlusion recorded correctly in retruded contact position (RCP)
- Lip support
- Overextension or Under extension
- Retention; Stability; Adaptation
12
Q
describe intercuspal position?
A
The complete intercuspation of the opposing teeth independent of condylar position, sometimes referred to as the best fit of the teeth regardless of the condylar position
13
Q
describe retruded contact psoition?
A
Guided occlusal relationship occurring at the most retruded position of the condyles in the joint cavities.
RCP is the most reproducible position
In complete dentures we do not use ICP as there is no opposing teeth
14
Q
describe retention of denture?
A
The resistance to displacement of a denture away from the ridge
15
Q
describe stability of denture?
A
Ability of a denture to resist displacement by functional stresses
16
Q
describe adaption of denture?
A
the degree of fit between a prosthesis and supporting structures
17
Q
what do you check fro denture examination out of mouth?
A
- base extension
- tooth position
- excessive wear of denture
- alterations since insertion e.g repairs, additions
- denture hygiene
18
Q
describe what primary impressions should do?
A
o Should “accurately record clinical relevant landmarks without excessive tissue distortion”
19
Q
how can stock trays be modified?
A
- putty
- soft red wax
- red composition
- ## green stick
20
Q
how do you reduce extension of stock trays?
A
- acrylic bur and straight handpiece
21
Q
what are limitations of stock trays?
A
o Trays are not made to measure
o Peripheral extensions - often over or under extended
o Limited sizes available
o Require master impressions to record denture bearing area with accuracy
22
Q
how do you record a primary impression?
A
Explain procedure to patient
Select trays - use tray with most appropriate extension
Assess this visually in the mouth by manipulating cheeks, lips and tongue
Change tray size if too big or small
Reflect – Are you happy with the tray – Use it no modification; Are you unhappy – add material or remove part of tray or both, select appropriate material
Ideally there should be ~4mm between tray flange and denture bearing area
Apply thin layer of adhesive over tray AND putty / wax/ composition and allow to dry
Mix alginate (dental nurse) Load tray (you) with alginate [see videos]
Seat loaded tray in mouth
Border mould muscles eg: cheeks and lips whilst constantly supporting tray
Once alginate set remove it with sharp sudden movement
23
Q
how do you do border moulding the lower anterior lingual sulcus?
A
sticking the tongue out to get correct sulcus depth
24
Q
how do you assess an impression?
A
- Are all the edentulous areas included?
- Are the sulci areas to be included in the denture recorded fully?
- Are deficiencies present due to air inclusion??
- Is the impression fit for purpose or not?
25
describe master impressions?
o Record denture bearing area, functional depth and width of sulci
o Use custom made special (individual) trays prescribed after primary impressions
26
how do you take master impressions?
o Clinical procedure:
Check extension - ought to be ~2mm short of sulcus depth to allow border moulding
Mould Stops: (Greenstick)
* position
* maintain spacing for material
* allow consistent placing of tray
INSERT TRAY in mouth TO MOULD STOPS - use greenstick WITH CARE!!
* Check extension and modify if necessary – add or remove material – add use greenstick; remove similar to stock tray with acrylic bur & straight handpiece
* Apply thin layer of adhesive - dry
* Less alginate required than primary impressions
* Excess material may obstruct airway or prevent seating of tray - retching
* Pre-pack where necessary – high arched palate/tuberosities
* Support tray throughout procedure
* Border moulding
* Assess the impression like primary impressions but more accuracy required
* Rinse with water and keep moist with damp paper towel
27
what do you aim for with master impressions?
o Well rounded borders
o Minimal air blows & none in important areas
o Impression centrally placed in tray
o Ensure all clinically relevant areas included
28
what are some special tray materials?
VLC resin PMMA (acrylic)
* pre-rolled sheets
* easy to mould
* very rigid - sometimes problems removing from model
Self-cure PMMA (acrylic) –
* problems rolling an even layer
29
what are advantages of special trays?
Accurate peripheral extension
Uniform thickness of material
Reduced amount of material -Less discomfort as tray fits individual mouth
Records denture bearing area more accurately
30
how to disinfect impressions?
Rinse in running water to remove saliva, blood or debris
Disinfect - for 10 minutes in disinfectant solution
Rinse thoroughly (having put on clean gloves)
Cover alginate impressions with damp paper towel
Label and place in a plastic laboratory bag
On laboratory prescription indicate that impressions have been disinfected which MUST be signed by supervising clinician
Take to laboratory asap for casting
Standard Operating Procedures (SOPs) often change, keep alert for changes
31
describe first clinical stage of replica dentures?
- clean dentures modify with greenstick if needed
- replicate using lab putty and stock trays out of mouth
- remove dentures from mould, clean and return them to patient
- disinfect moulds
- take to lab with prescription
32
describe first lab stage of replica blocks?
lay shellac base onto fitting surface of mould
pour molten wax into moulds
once wax set remove completed wax replica blocks on shellac bases
33
describe 2nd clinical stage of replica dentures?
master impressions and jaw bite reg
- disinfect replica blocs
- upper master imp on replica block
- lower master imp on replica block
- jaw reg with both record blocks
- choose shade (and moulds)
- disinfect registered blocks/imps
- take to lab with prescription
34
what is 2nd lab stage of constructing replica dentures?
cast impressions, mount casts and set up
- cast impressions
- mount casts on articulator
- set upper and lower teeth in wax
- tidy up wax work
35
what is 3rd clinical stage of constructing replica dentures?
try in (trial)
- disinfect try in
- try in the teeth set in wax
- try in checks
- re-register/make other changes as required
- disinfect try in
- take to lab with prescription for (retry) or finish
36
what are try in checks?
o Vertical dimension of occlusion
o Even contact in retruded contact position
o Lip support
o Occlusal planes – anterior/posterior
o Lower teeth over ridge Speech
o Retention & stability
o Base extensions
o Appearance
37
what is 3rd lab stage for constructing replica dentures?
process (finish) dentures
- wax up
- flasking
- deflasking
- trim and polish denture
38
what is 4th clinical stage of constructing replica dentures?
insertion (finish)
- disinfect dentures
- insert and insert checks
- denture wear and cleaning instructions
- arrange review visit (1-2 weeks)
39
what are insertion checks?
o Vertical dimension of occlusion
o Even contact in retruded contact position
o Speech
o Retention & stability
o Base extensions
o Appearance
o Comfort
40
what is 5th clinical stage for constructing replica dentures?
review
- review and review checks
- adjust (ease) if required
- arrange further review if required
41
what are review check?
- pain/redness/ulceration
- function
- aesthetics
- speech
- recheck occlusion/vertical dimension
42
what is 1st clinical stage for constructing conventional complete dentures?
primary impressions
- take primary imps using stock trays
- disinfect
- take to lab with prescription
43
what is first lab stage in constructing conventional dentures?
primary casts and special trays
- pour casts
- remove impression from casts
- make special trays from primary cast
44
typically what normally sized spacer do you use?
3mm
45
what is 2nd clinical stage for conventional complete?
master imps
- disinfect special trays
- master imp on special tray
- mark post dam for upper
- disinfect imp
- take to lab with prescription
same for lowers but no post dam
46
what is 2nd lab stage for conventional completes?
master casts and record blocks
- pour master casts
- make record blocks
47
what is 3rd clinical stage for conventional dentures?
jaw (bite) reg
- disinfect record blocks
- register the occlusion; choose shade, setting and mould
- disinfect registered blocks
- take to lab with prescription
48
what is 3rd lab stage in construction of convetionals?
mount casts and set up
- put registered blocks on holding casts
- mount on articulator
- set up teeth
- setting up upper anterior teeth
- setting up lower anterior teeth
- setting up posterior teeth
49
what is 4th clinical stage in conventional completes?
try in (trial)
- disinfect try in
- try in teeth set in wax
- try in checks
- re-register/make other changes as required
- disinfect try in
- take to lab with prescription for retry or finish
50
what are try in checks for conventional dentures?
o Vertical dimension of occlusion
o Even contact in retruded contact position
o Lip support
o Occlusal planes – anterior/posterior
o Lower teeth over ridge
o Speech
o Retention & stability
o Base extensions
o Appearance
51
what is 4th lab stage for conventional completes?
process (finish) dentures
- wax up
- flasking
- deflasking
- trim and polish denture
52
what is 5th clinical stage for conventional completes?
insertion (finish)
- disinfect dentures
- insert and insert checks
- denture wear and cleaning instructions
- arrange review visit (ideally 1-2 weeks)
53
what are insertion checks for conventional completes?
o Vertical dimension of occlusion
o Even contact in retruded contact position
o Speech
o Retention & stability
o Base extensions
o Appearance
o Comfort
54
what is 6th clinical stage for conventional completes?
review
- review and review checks
- adjust (ease) if required
- arrange further review if required
55
what are the review checks for conventional completes?
- pain/redness/ulceration
- function
- aesthetics
- speech
- recheck occlusion/vertical dimension
56
what is an impression?
o A reverse or negative form of the tissues which is converted into a positive model/cast using plaster or stone or a mixture of both plaster and stone.
57
how to assess fit of stock trays?
o 1. Look inside mouth and guestimate the correct size
o 2. Try in tray & look inside mouth
Too small – flanges hit the ridge
Too large – stretches the mouth or feels uncomfortable or cannot get it in the mouth
58
what are limitations of stock trays?
o Rarely fit the mouth accurately
o Often require modification
o May be difficult to obtain necessary border seal
o Remember – Do not overload trays; Occasional pre-packing
Always prescribe for special trays
59
where do you position yourself for impression taking?
o Upper: Stand behind
o Lower: Stand in front
o Both: Get the chair height correct for your height (change height between U & L)
o Patient: Sitting up not flat
60
what is the technique to taking impressions?
1. Rehearse tray insertion before loading then rotate the loaded tray into patient’s mouth
2. Use firm pressure to seat the tray home
3. Border moulding whilst supporting the impression with other hand
4. Lower – tongue movement; Upper – partial mouth closure
5. Do not remove until set
6. Remove the impression
7. Inspect the impression
Note: Talk to your patient throughout; if retches deep breaths through nose, tilt head forward & calm patient – Effective communication
61
what do you look for when you evaluate impression?
o General adaptation & surface detail. For example: No significant air blows
o Appropriate sulcus depth and shape “functional sulcus”
o Tray placed correctly to ensure ridge is in centre of tray
o All appropriate landmarks are included – entire denture bearing area included including palatal extension to post dam
o Anterior lingual sulcus – tongue has been protruded
o Impression is fixed to the tray
62
what are the key points for a lab prescription?
Stage
* What you want done; not what you have done
When
* Date/time you want the work for
Label
* Patient label (all 3 copies)
Appliance
* Full (replica or conventional); material
Who
* Student name & email address; Supervisor name & stage signed
What
* Is to be done with the work you send & what do you want back
Safety
* Disinfected
Specifics
* Upper/Lower/Both; Shades/moulds/materials; tray handles; postdam(s); special instructions
63
what are tissue stops used for and where you place them?
Used with spaced trays - primary and secondary impressions
To ensure uniform thickness of impression material
To help localise tray during impression taking
Lower tray - place in canine region and over retromolar pads
Upper tray - place in canine region and along post dam area
Greenstick or incorporated into tray in acrylic
64
what is mucoimpression?
pressure is applied to the mucosa so that the shape of the tissues under load is recorded (MOST impressions this)
65
what is mucostasis?
minimum pressure is applied to the tissues to record their shape at rest
66
what are the diff types of record blocks? and their features?
- wax block only - less retentive, cheap, lots space for setting teeth
- shellac base - more stable, more expensive, limited space for setting teeth
- heat cured base- very stable, expensive least space for setting teeth
67
what is step 1 for jaw reg?
adjust upper record block for retention
Try in block often bulky
Want it to retain – but wax poor adaptation
Overextension of the peripheries = loss of retention
Too much lip support and it will drop
Use the wax knife and hot plate/heated pallet knife to make adjustments
May need to adjust the rim labially/buccally
68
what is step 2 for jaw reg?
Adjust upper record block for tooth position
- First… Examine current denture.
* Patient’s opinion on tooth show
* Modify or keep
* Age appropriate?
LIMBO
69
what are the parts of LIMBO?
- lip support
- incisal plane
- midline
- buccal corridor
- occlusal plane
70
what does the incisal plane of limbo involve?
- visual judgement
- photographs of natural teeth
- lip level
- lip during speech
- age
- 1-2mm of show
71
what is buccal corridor in limbo?
important in small percentage of people - space in corners when you smile
72
what is step 3 for jaw reg?
adjust upper record block for occlusal planes
- anterior - interpupillary
- posterior - ala-tragus
73
what is step 4 for jaw reg?
Lower tooth position & horizontal jaw relationship
- neutral zone
- In practical terms:
* Anterior teeth - Over ridge
* Posterior teeth - Over ridge
* Polished surfaces – No buccal overextension – cheek dislodgement; lower lingual – wider at base than apex so tongue does not dislodge
* Adjust lower block with neutral zone in mind
Class I skeletal relationship:
Class II Div 1 skeletal relationship:
Class II Div 2 skeletal relationship:
Class III skeletal relationship:
Retruded contact position (RCP)
Muscular position
74
what is definition of neutral zone?
the potential space between the lips and cheeks on one side and the tongue on the other; that area or position where the forces between the tongue and cheeks or lips are equal
75
what is class 1 skeletal relationship?
* Shallow overjet and overbite
76
what is Class II Div 1 skeletal relationship?
Increased overjet and shallow overbite
77
what is Class II Div 2 skeletal relationship?
Increased overjet and deeper overbite
78
what is class III skeletal relationship?
* Edge to edge incisors and posterior crossbite
* Try avoid reverse overjet anteriorly (retrocline incisors)
79
what is retruded contact position?
* Guided occlusal relationship occurring at the most retruded position of the condyles in the joint cavities.
* Limited by the lateral ligaments of the TMJ
* Remains the same throughout life, assuming nothing adverse happens to the condyles
* A reference point for mounting casts on an articulator
80
what is muscular position in jaw reg?
* The position of closure produced by balanced muscle activity raising the mandible from rest to initial contact
* Beware postural class III occlusions – old worn dentures
81
what is step 5 for jaw reg?
Measure vertical dimension & establish face height
- OVD
-RVD
- FWS
82
what is occlusal vertical dimention?
the distance between a set point on the maxilla and a set point on the mandible when the (denture or natural) teeth are in maximum intercuspation
83
what is resting vertical dimension?
- when the mandible is at rest with patient upright
- Rest = postural position = position mandible takes up without any conscious control
84
what affects RVD?
o Stess
o Pain, anxiety
o Tense up facial muscles
85
what is Freeway space?
* RVD – OVD = FWS
86
what is freeway space usually?
2-4mm
87
describe excessive FWS?
o Reduced masticatory efficiency
o “Overclosed” facial appearance and cheek biting
o TMJ symptoms
88
describe reduced (inadequate) FWS?
o Excessive load on denture bearing area
o Continuous muscular activity results in pain
o Aesthetic complaints – “Teeth too big”; “Show too much teeth”
o Noisy dentures
89
how do you measure OVD and RVD?
- Willis bite gauge
- Dividers
90
what is step 6 for jaw reg?
record registration
- * Are blocks trimmed so teeth will be in the neutral zone?
* Do you have even contact with upper block?
* Is OVD correct for patient, with adequate FWS?
* Is centre line correct?
* Are occlusal planes appropriate?
91
what is step 7 of jaw reg?
Select shade, mould & setting
92
what are the displacing forces of complete dentures?
o Gravity
o Muscle activity
o Sticky foods
o Function
93
describe adhesion in complete dentures?
o The physical attraction of unlike molecules for each other
Saliva and mucous membrane
Saliva and denture base
o Maxillary versus mandibular
o Extension over the denture bearing area
94
describe cohesion in complete dentures?
o The physical attraction between similar molecules
Salivary film
95
how to achieve optimum retention and stability with completes?
o Fitting (basal) surfaces
o Polished surfaces
o Occlusal surfaces
96
describe fitting (basal) surfaces for optimum retention and stability?
Base shape
Adaptation to mucosa
Greater base extension achieved in the maxilla
Require full coverage of the denture bearing area
Importance of adequate post dam seal for the maxillary denture
Importance of adequate extension into the retromylohyoid fossa (lingual pouch)
Need good adaptation to mucosa
Importance of impressions with good surface detail
o Polished surfaces
o Occlusal surfaces
Use of undercuts:
* Labial undercut
* Bilateral soft tissue undercuts
* Bilateral boney undercuts
End result should be well extended casts with good surface detail
97
describe occlusal surfaces importance for optimum retention and stability?
Arch form
Occlusal plane level
Tooth position
* Relation to the edentulous ridge
* Relation to the tongue and oral musculature
Oral musculature
* Tongue control
Errors in tooth positioning
* Lingual overhangs make dentures unstable
Creating a balanced occlusion when eating
98
factors that can make the retention and stability difficult?
o Atrophic ridges
o Patients with an incomplete palate
- cogentital cleft
o Patients with soft tissue that is mobile
- fibrous ridge
- free flap
o Patients who cannot tolerate base extension
- gagging
o Cobalt Chromium base plates adapt less well than acrylic resin
o Insufficient saliva
- salivary gland disease
99
aids to denture retention and stability?
o Denture adhesives
o Linings
o High success rates using titanium
> 90% in mandible
> 80% in maxilla
o Implants
100
what is important to think about for anterior tooth selection?
Function
Appearance
Speech
101
Factors which may influence the choice of artificial teeth (& gums)?
o Dentist factors
Previous dentures
Ageing
Size of facial skeleton & skeletal class
Physiological pigmentation
Dentist perceptions
o Patient factors
Influences of others
Lifestyle, relationships & goals
Psychological factors – tooth loss
Perceptions of ageing
Self-esteem
Smileorexia
102
what materials are used for artificial teeth?
- acrylic based
- porcelain based
- composite resin based
- combinations?
103
how to choose moulds for partial dentures?
* Sometimes follow size/shape of existing teeth & sometimes choose a mould depending on how many teeth you have for the technician to follow
104
what are some myths of shapes of artificial teeth?
Leon Williams classification
* Shape of face = shape of tooth
Frush and fisher dentogenics
* Men – square and angular teeth
* Women – curved and rounded
105
what do you use for checking tooth position?
alma gauge
106
what is golden rule for anterior tooth position
- let patient see the appearance at try in and record their opinion and approval in records
107
what do you decide with selection and position of posterior teeth?
o Size
o Width
o Length and number of teeth
o Position
o Occlusal surfaces
108
what are factors which may influence choice of teeth?
o Ridge
o Neuromuscular control
o Reproducibility of occlusal position
109
what must you avoid when selecting lower posterior teeth?
lingual overhangs
110
how are lower posterior teeth placed?
o Lowers are placed on the crest of the ridge
111
how are upper posterior teeth placed?
o Uppers are usually placed slightly buccal to the ridge without compromising the border seal of the denture
112
what is orientation of the occlusal plane?
o Parallel to the ala-tragus line
113
what must you consider before pt arrives?
Do you have the lab work?
Is it the correct patient?
Has the lab work been damaged in transit?
Is the lab work present what you expected from the prescription?
Is the mould and shade what you requested?
Have special instructions been adhered to? Eg: Diastema/imbrications.
114
what must you consider before you insert the try in?
Are the try-in bases stable on the casts?
Are try-in borders smooth, rounded and with no sharp edges?
Is the border extension shaped to the depth and width of the functional sulcus?
115
what must you consider when you look at try in on articulator?
* From front:
o Is the wax distorted or well adapted?
o Check the occlusion. You are looking for even occlusal contacts; not eg. anterior open bite (unless asked for specifically on prescription)
o Is there an anterior open bite or good contact Are the centre lines coincident? Is the pin on the table?
* From lateral view (both sides):
o Look at the overbite and overjet. Is it what you expected it to be?
o Look at the occlusion on the molars. Are there even contacts?
116
what must you consider when you look at lower try in?
* Occlusal view:
o Are the posterior teeth set over the ridge?
o Are the anterior teeth set over the ridge?
o Is the position of the teeth likely to affect the denture stability?
o Correct number of teeth on try-in?
o Correct shade & mould?
117
what must you consider when you look at upper try in?
* Occlusal view:
o Are the posterior teeth set buccal to the ridge?
o Are the anterior teeth set how you expected?
o Is the position of the teeth likely to affect the denture stability?
o Correct number of teeth on try-in?
o Correct shade & mould?
118
what must you consider when you look at upper cast?
* Occlusal view:
o Has a postdam(s) been cut?
o If not:
o Draw on cast site with indelible pencil Prescribe for the technician to cut post dam(s) Sometimes ask for a double post dam
119
what must you do when you put the try in dentures in the mouth?
- assess each denture independently and then together
- allow time to settle
- insert one denture at a time (moisten)
- if maxillary denture is inserted first it can be dislodged when the mandibular denture is inserted
120
what is considered with regards to base extension during try in?
- hold tissues away from denture - does it drop? if yes - possible underextension
- any overextension of the peripheries and it will drop when you manipulate tissues
- too much lip support and it will drop
121
what must you ask patient to do with dentures in?
count from 60-70
122
what do you do if something is wrong during try in?
Do you need a re-try appointment?
Can you correct it issue at the chairside?
Can you prescribe for change to be made in laboratory prior to finish?
Can you correct issue at insertion?
123
what do you do if there is a speech problem during try in?
* If the teeth make contact during speech often insufficient FWS so OVD needs to be reduced - re-register at new OVD > lab for remount, reset for re try-in
* Significant whistling sound during “s” sounds then air is escaping too much. OVD may need to be increased or the anterior tooth position changed (e.g. if set in Class II by mistake) - re-register at new OVD > lab for remount, reset for re try-in
* Minor issues with speech may simply be due to poor adaptation of wax/shellac of try-in or bulk of a new denture patient unused to > reassure > Insertion
124
what if there is an aesthetic problem during try in?
* Shade/mould incorrect – Choose again, > lab for reset with new teeth for re try-in
* Midline incorrect – Mark new midline, > lab for reset all teeth with existing teeth for re try-in
* Minor changes to tooth position eg imbrication/twists – you alter at chairside until patient approves > lab for insertion
* Major changes to tooth position eg major LIMBO errors – re-register > lab for reset for re try-in
125
what if there is an extension problem during try in?
* Minor overextension – Modify wax; mark on master cast maximum extent of flange > lab with specific instructions for insertion
* Major overextension – Usually need to go back to master imp stage
* Minor underextension – 2 options: 1) wash impression in try in (closed mouth technique) > lab for casting/mounting > re try-in 2) Proceed to insertion stage but do not insert at that stage but instead reline denture
* Major underextension – Usually need to go back to master imp stage
126
what if there is a vertical dimension error during try in?
* Always triggers a re-try in
o If OVD is increased teeth need to be removed from one or both dentures and replaced with a wax rim.
o If OVD is decreased a wax rim can be added to the teeth on one or both dentures or teeth removed from one or both dentures and replaced with a bigger wax rim.
127
what if there is an occlusal error during try in?
MAJOR
if ovd correct
- if uneven contact some or all teeth need to be removed from one or both dentures and replaced with wax rim, re-register > remount > rest > re-try in
if ovd incorrect
- correct ovd by removing teeth from one or both dentures and replace with wax rim, re-register occlusion to eliminate occlusal error> reset> re-try in
MINOR
- selective grinding at either try-in or insertion
- use articulating paper
- remember try-in bases are unstable and denture moves
- adjust carefully
-BULL rule
-
128
what is BULL rule?
- buccal upper (palatal surface of buccal cusp) and lingual lower (buccal surface of lingual cusp). adjust the contacting surfaces rather than the tips of the cusps
129
what happens if you need a re-try in?
- record new reg with jaw reg paste
- replace lower teeth with wax rim. trim rim to even contact
130
what must you do before you insert the dentures?
Check all 3 surfaces of the denture for blebs, sharp edges, acrylic flash and quality of polish.
Ensure there is no porosity or inclusions in the acrylic.
Look for large undercut areas that may prevent seating or cause pain
Are you happy with the border extension?
131
what kind of reasons will adjustments be needed?
Roughness can cause pain
Extension into Undercuts can be painful
Overextension may cause pain
Occlusion may require adjustment
Smooth & polish if necessary (e.g. pumice)
132
what is more retentive lower or upper?
upper
133
what happens if there is retching?
reduce palate
134
for lip support changes what can be done?
minor labial flange reduction only
135
how to re-record occlusion at insertion?
1. remove lower teeth if upper acceptable
2. replace with wax rim
3. re-record registration (remember to measure FWS)
4. prescribe another wax re try-in
5. give both dentures to lab
136
what are common areas of discomfort during insertion?
- undercut areas e.g tuberosity; anterior labial flange; tori
- areas of poor support e.g mylohyoid ridge; very resorbed knife-edge ridge; flabby ridges
137
what must you not do during insertion?
overadjust
138
what is used to identify where discomfort is?
pressure indicating paste PIP
139
what do you do with PIP?
- paint on area
- insert press firmly 0 manipulate left posterior cheek in pressure area PIP rubs off
- adjust areas shown with acrylic bur
140
what are some wear instructions you give patient?
- manage expectations
- perseverance, some discomfort is normal, may lisp, eating may be difficult, wear as much as possibel
- arrange review
141
what is an immediate denture?
o Any removable dental prosthesis fabricated for placement immediately following the removal of a natural tooth/teeth
142
what are some advantages of an immediate denture?
o A guide for aesthetics
o Speech
o Function
o Self esteem
o Avoid drifting / tilting/overeruption of remaining teeth
o Promotes Health
o Better adaptation to dentures
o A guide for OVD
o Post-extraction healing
o Ridge form preservation
o Prevents collapse of facial musculature
143
what are some disadvantages of immediate?
o Temporary prosthesis due to resorption (Manage expectations)
Guesstimate as to how healing will proceed
Poor adaptation to ridge very quickly
Plans can change due to pain/swelling during denture making process meaning earlier extraction
o Increased complexity of prosthetic stages
o Ongoing maintenance needed eg relines; adjustments
o Increased cost & patient visits
o Limitations on approving aesthetics at try-in
o Undercut areas problematic as no bone resorption at time of extraction:
Full flange
Half-flange
Gum-fitted
144
how are the complexity of prosthetic stages increased?
Impressions
* poor fit stock trays, loose teeth, malpositioned teeth, hard to get denture bearing area
Occlusion
* Index teeth may be present and useful for OVD but drifted, tilted, overerupted teeth cause issues in recording occlusion
Design
* Limited to acrylic plate – simple wrought clasps in partials
Try-in
* limited to those teeth already missing but can check extensions ,occlusion, OVD, shade
Insertion
* Correct teeth on denture?, traumatic extractions van make insertion difficult
145
what are some potential contraindications of immediates?
o Some ORN/MRONJ areas
o Sometimes pre-chemo/radiotherapy
o Denture not required
no aesthetic/major functional deficit
o Some pathological issues
eg large cysts
o Some major fractures
eg: maxilla/mandible
o Lack of patient consent
o Dementia
146
what are clinical stages of immediates?
o Same sequence as for other dentures
occasional skip/modify stages
o Examination and assessment
teeth to be removed are assessed clinically and radiographically if required.
o Medical history
MRONJ/ORN risks/anticoagulants
o Assess degree of difficulty of extractions
sometimes coordination with oral surgery specialist/need for sedation
147
what is the initial aftercare of immediates?
o Dentures to be kept in for 24hrs – post op instructions
o Ideally review appointment on day after insertion/ soon thereafter
o Remove dentures - examine mouth for healthy clots. Identify any areas of inflammation - ease denture
o After 24hrs – advise warm saline mouthwash and patient to remove denture after mealtimes, to rinse mouth and clean denture – soft toothbrush, soap and water
148
what is the aftercare after the initial aftercare of immediates?
o Review after 1-2 weeks - further adjustment as required
o May need denture fixative
o Review after 1 month - assess adaptation
o Consider temporary reline
o May need repeat reviews, more temporary relines, soft or definitive relines
o Usually replace at 6 months to 1 year depending on rate of resorption
149
when do you decide to replace immediate dentures?
6 months to 1 year
150
what is a one stage immediate denture?
o To replace one or two anterior teeth e.g. trauma/abscess/root fracture
o Upper and lower impressions recorded
o High quality interocclusal record required to confirm occlusion
o Choose shade Prescription to laboratory including design and which teeth to be extracted
o Extraction(s) and insertion of denture at next visit
