Pros Flashcards
1
Q
What are the components of an RPI? (3)
A
Rest on mesial surface,
Proximal plate on distal surface,
gingivally approaching I-Bar.
2
Q
What is the mechanism of action for an RPI (3)
A
Mesial rest acts as axis of rotation.
During occlusal load
The proximal plate and I-bar rotate downwards and mesially respectively around the axis of rotation
The I-bar and proximal plate disengage from the tooth/undercuts.
Thus, potential traumatic torque is avoided
3
Q
An 85 year old lady attends your practice for the first time. She is complaining of generalised pain underneath her
lower complete denture on the left side. She is also edentulous in the maxillary arch and successfully wears a
complete upper denture. She gives a history of the denture becoming progressively looser during the last 2 years.
On examination you suspect that the cause of the pain may be related to an unerupted sound second premolar
tooth that is now partially visible.
Describe two common radiographic views used to assess the position of the tooth. (4 marks)
A
OPT and (mandibular) oblique occlusal
2X PA’s at differing angles to one another
= Parallax: My pal follows me rule or SLOB
4
Q
An 85 year old lady attends your practice for the first time. She is complaining of generalised pain underneath her
lower complete denture on the left side. She is also edentulous in the maxillary arch and successfully wears a
complete upper denture. She gives a history of the denture becoming progressively looser during the last 2 years.
On examination you suspect that the cause of the pain may be related to an unerupted sound second premolar
tooth that is now partially visible.
Given that, in this patient, the mandibular denture bearing area is very resorbed and the patient has osteoporosis.
What possible complications could arise if extraction of this tooth was attempted? (4 marks)
A
Regulars: pain, swelling, bruising, infection, dry socket,
Mandibular fracture (atrophic mandible)
MRONJ (bisphosphonates for osteoporosis)
Immunosuppressed & elderly = higher infection risk
Nerve damage since mental foramen closer or if theres a fracture
5
Q
An 85 year old lady attends your practice for the first time. She is complaining of generalised pain underneath her
lower complete denture on the left side. She is also edentulous in the maxillary arch and successfully wears a
complete upper denture. She gives a history of the denture becoming progressively looser during the last 2 years.
On examination you suspect that the cause of the pain may be related to an unerupted sound second premolar
tooth that is now partially visible.
You decide, after discussion with the oral surgeon, that the tooth should remain in situ. Outline your approach for
the design of a replacement lower denture that would be stable and comfortable in function. (12 marks)
A
- Check the denture is retentive/ has sufficient support and stability
- Check occlusion.
- In jaw registration stage we are checking the RVD/ OVD/ FWS and neutral zone.
- Get the patient to decide their tooth shade & shape
- Check extension- so that it does not impinge on frenal attachments or the neutral zone .
- Place a relief in the region of the 2nd molar (leaves space for the application of a soft lining material under the area of the premolar)
6
Q
What measurements are required for a lingual bar?
A
8mm depth. 4mm height of bar, 3mm from the gingival margin, 1mm from the depth of the functional sulcus of floor
of mouth
7
Q
3 differences between new and old dentures on image (3)
A
Increased occlusal Vertical dimension - tooth wear,
Flange extension (and thickness?)
Tooth shade
8
Q
Name anatomy of the upper and lower jaws.
A
9
Q
Define Support retention and stability, indirect retention.
A
Support- Resistance to occlusally directed loads e.g. rest seats.
Retention: resistance to vertical displacement (can be mechanical e.g. clasp/ musclar e.g. Buccinator/ orb.oris/ Physical e.g. cohesion and adhesion.
Stability: is resistance to horizontal displacement forces in function (keep denture in neutral zone)
Indirect retention: Resistance to rotational displacement forces. It is provided by supporting components e.g. a rest
preventing distovertical rotational displacement of a saddle. Should be ideally 90° to the axis of rotation. Should be
on the opposite side of the axis of rotation to the displacing force. Mainly used in free end saddles.
10
Q
3 ways upper complete retained (3)
A
- Mechanical: via clasps, guide planes
- Muscular: via action on muscles on the shape of the polished surface of denture
- Physical: adhesion (Forces of saliva on the denture)
/cohesion (forces within the saliva such as viscosity)
atmospheric pressure
Extension into;
sulcus, vibrating line/post dam region = peripheral seal, hamular notches
11
Q
What is the Biometric guidance setting upper and lower teeth (5)
A
Aim to place teeth in their pre extraction sites;
- Maxillary teeth placed buccally to the ridge promotes lower denture stability.
- Mandibular teeth placed over the ridge so the palatal cusps of uppers occlude with fossa of lowers and the forces are appropriately directed.
- Positioning lower teeth over the ridge reduces tongue restriction
12
Q
What is the aetiology of denture stomatitis? (3)
A
Poor denture hygiene
dentures worn at night
immunocompromised.
13
Q
How do we manage denture stomatitis? (7)
A
Local measures first:
Denture Hygiene Instruction
brush palate daily
clean denture thoroughly - soak in CHX (0.2%)or sodium hypochlorite (acrylic only) for 15 mins 2x per day.
Wear dentures as little as possible
Miconazole oromucosal gel (20mg/g) applied 4 times daily after food.
Fluconazole 50mg (1 tablet for 7 days)
new dentures made when health restored
14
Q
How do you restore freeway space in very worn dentures?
A
occlusal pivots-
restore occlusal surface with auto-polymerising acrylic resin (provisional)
A gap between posterior teeth in mandibular protrusion makes the occlusion unstable.
15
Q
What problem can occur with a complete upper denture occluding with a partial lower? (1)
A
Combination syndrome
-Natural teeth producing alot of force aginst the edentulous maxillary ridge.
Resulting in a ‘flabby ridge’ due to
- trauma to mucous membrane -> ulceration/chronic discomfort under denture -> bone loss & fibrous tx deposition
* Papillary hyperplasia of the hard palate
* Bone loss from the anterior part of the maxillary ridge.
- Hypertrophy of the tuberosities
- Extrusion of mandibular anteiror teeth
16
Q
Why does combination Syndrome occur. (3)
A
Lower natural teeth apply greater forces to the anterior upper denture over a prolonger period of time
Continuous displacement results in excessive and rapid bone loss of anterior alveolar ridge
This is replaced by excess fibrous tissue.
17
Q
How do we manage combination syndrome? (2)
- how do we achieve this
A
Treatment:
* New denture covering the whole denture bearing area including priamry load bearing sites with good peripheral seal/post dam (reduces trauma to the denture bearing site)
- AND Opposing arch denture providing posterior support.
Take a mucostatic impression so the tissues are recorded at rest.
Use a 2 stage impression with a medium body first
Then cut out impression material and make hole in tray over flabby ridge and take 2nd impression with light body.
OR
Can use window technique where relief hole is cut in special tray where flabby ridge is to allow flow of impression material and leave tissues undisplaced.
1st imp = use mucocompressive e.g. zinc oxide eugenol
2nd imp = mucostatic imp using a low/medium viscosity impression material in the ridge area
18
Q
Define Kennedy Class 2 Mod 1
A
Unilateral free end saddle with 1 bounded saddle.
19
Q
What is a system of design used for designing partial dentures?
A
- outline saddle area,
- support,
- retention,
- stability and reciprocation,
- connector - minor and major
- simplify
20
Q
Give examples of maxillary and mandibular connectors designs
Provide advantages and disadvantages for each.
A
Maxillary:
midpalatal strap/horsehoe
Adv- Not covering gingivae/full palate.
Disadv- Not as much mucosal support
Full palatal coverage
Adv-provides mucosal support
Disadv- covers the palate (cannot feel hot fod or drinks/
Mandibular:
Lingual plate:
Adv- thinner diameter/ less edges for the tongue to explore.
Disadv-covers the gingival margin
Lingual bar
Adv- Gingival margin is clear
Disadv-Need the 8mm space.
Plate/strap:
Maxillary - midpalatal, horseshoe
Mandible - lingual plate
– thin in cross section but rigid
- fewer edges for tongue to explore
X - mucosal coverage (+/- gingival margin coverage)
Bar:
Maxillary - anterior posterior ring
Mandible - lingual bar
- gingival margin clearance
- less palatal coverage
- lingual bar well tolerated
X- More edges for tongue to explore
X - thicker in cross section to ensure rigid
X - Lingual bar hard to clean
21
Q
What is an RPI?
A
Stress relieving clasp system used in free end saddles.– rest seat mesial to saddle area, proximal plate and I-bar.
Rest mesially acts as axis of rotation. As the proximal plate and I-bar rotates downwards and mesially (respectively) around the axis of rotation
during occlusal load. The I-bar and proximal plate disengage from the tooth/undercuts. Thus, potential traumatic torque is avoided
22
Q
What is Alwood and Howell’s classification of a ridge?
A
I. Dentate
II. Post extraction (can see the socket)
III. Broad
IV. Knife-edge
V. Flat (no alveolar process)
VI. Submerged (loss of basal bone leading to an inverted ridge)
23
Q
What is a knife-edge ridge?
A
Rapid resorption of lingual and buccal alveolar bone with a hard sharp bony presentation with thin gum overlying it
24
Q
Name 3 reasons for a knife-edge ridge
A
Immediate dentures, periodontal disease before XLA, traumatic surgery for XLA.
25
How is a knife-edge ridge managed for a complete denture? (3)
Soft reline on denture fitting surface
Surgical removal of sharp bony spots if painful
If there are specific sore areas (relief can be put on the denture to relieve the pressure there)
26
What is the difference between a soft lining and a tissue conditioner?
A soft lining may be used to reline a healthy mucosa;
as a cushion/shock absorber
In atrophic/knife-edge ridges.
Those with parafucntional habits
A tissue conditioner is a more immediate and short term option and is used in unhealthy(inflammed)/ulcerated mucosa to aid healing.
It also dissipates forces but is a more short-term option.
27
What is a functional impression?
An impression taken with a tissue conditioner. The material is applied and the patient wears the denture and impression in function for approx. 24 hours.
They return and the impression is sent to the lab for a reline.
28
Other than remaking them how can you improve the retention of dentures? (4)
Adjustment of any overextended areas:
Overextension lingually- tongue will move the denture
Overextension buccally- Soft tissues will move it.
(hard?) Reline -
Soft- replacing part of the surface material (e.g. a smaller gap affecting retention)
Hard- improving the post dam region to provide a better peripheral seal)
Rebase - replacing the entire fitting surface (e.g. improving the post dam region for a peripheral seal)
Add clasp
Adhesive
Other ways retention can be improved (remaking them)
Implant retained denture.
Precision attachments (Interlocking piece between the crown and the denture),
29
How can you check retention clinically? (4)
Partial dentures
Pull vertically on anterior teeth region to see if the denture pulls out of the patients mouth.
Complete denture
Does it drop when we:
* Pull the tissues out the way of the denture
* Tissues are manipulated
* Patient moves their lips.
Lower denture- does it move when patient moves their tongue forward(on lower denture)
‘Pull’ on premolars – push on anteriors to check post dam.
30
Describe the process of making a replica denture
Consent and explanation.
Stage 1-replica mould of old denture
1. Clean the dentures (modify with greenstick)
2. Replicate the denture using lab putty & stock trays out of the mouth.
Place Adhesive then lab putty on the inner surface of one tray and the outer surface of the other tray.
Seat the denture occlusal surface down on the inner tray putty. Mould the putty to 2mm of the edge of the denture. Place vaseline and locating notches (aid removal)
Place lab putty on the fitting surface of the denture & sit the 2nd tray outer surface down.
3. Once set-Remove the dentures from the mould/& disinfect & send to lab. (For replica wax blocks on a shellac base)
Stage 2:
Take master impressions using the replica blocks. (e.g. extrude polyether)
Complete the jaw registration with both record blocks.
Continue as normal dentures from here.
31
What problems can an incorrect OVD give? (7)
Folded comissures of the mouth due to reduce facial height.
Angular cheilitis (infection of the comissures)
Clicking teeth when eating (Reduced FWS)
Whistling (Increased FWS)
Incompetent lips (increased facial height)
TMD aggravation
Pain in mandibular muscles
occlusal trauma in RPD.
If OVD is excessive
= progressive pain throughout day
= Sore TMJ and MOM
= whistling speech
If OVD insufficient
= lack face height
= deep creasease at commissures
= repeated angular cheilitis
32
Denture stomatitis- What microbe is involved. Give the 4 virulence factors of this microbe?
Candida albicans.
Altering the target site to prevent azoles binding
Changing the cell membrane composition to prevent the insertion of polyene into the cell membrane.
Hyphae causing damage to host tissue.
Hydrolytic enzymes- attachment to host cells & causes cell structure.
33
What is your initial treatment plan to treat denture stomatitis?
Local measures:
Brush the palate daily
Clean the dentures (Soak in Chlorohexidine or sodium hypochlorite if acrylic for 15 minutes twice a day)
Leave the dentures out as much as possible during treatment.
Denture care advice:
- Remove denture at night & store it in water.
- Clean with a dry tooth-brushing over a sink of water after each meal and at night,
If patient uses an inhaler advise that they should rinse after inhaler use.
**Denture adjustment **
Ensure the dentures are adjusted (a loose/ ill fitting denture can make the problem worse)
We can use a temporary reline on the fitting surface of the denture to prevent pressure on the infected gingivae until it heals. (e.g. Viscogel)
**Drug treatment**
If initial OHI & chlorohexidine doesn't work or patient is immunocompromised.
Good OH patient/ no dry mouth- Topical or systemic antifungal.
Dry mouth patient- topical antifungal (systemic should be avoided)
Immunocompromised- systemic antifungal + topical antifungal.
Topical- Miconazole oromucosal gel (20mg/g) pea sized amount applied after food 4 times daily.
Systemic- Fluconazole 7x 50mg capsules 1 daily.
Nystatin 30ml- used for when patient is on warfarin or statins (Fluconazole and miconazole contraindicated)
34
Name 5 medicines you could use for a denture stomatitis
Topical:
* Miconazole = 20mg/1g use: pea size 4x daily (after food) for 7 days
* Nystatin = oral suspension 30ml use: 1ml after food 4x daily for 7 days
* Chlorohexidine = 0.2% use 10ml 2x daily
Systemic:
* Fluconazole 50mg capsules use: 1x daily for 7 days
* itraconazole
35
Patient has denture stomatitis- you decide they need a new denture - What can you do in the short term for the patient’s current denture? (2)
what are the advantages?
Improve denture hygiene
Add a temporary reline e.g. coe-comfort or viscogel.
This:
Allows Inflammation of the denture bearing muocsa to resolve (need to regain normal volume and contour prior to our new impression)
Prevents pressure on the infected oral tissues.
36
Where should your post dam be?
1-2mm anterior to the palatine fovea extending from hamular notch to hamular notch along the vibrating line.
vibrating line = this is the junction of the hard and soft palate and iscompressible tissue.
37
What is the distal extension of a lower complete denture?
2/3rd onto retromolar pad.
38
Why is the buccal shelf used for support?
It is non-resorbable.
39
What anatomical features help set the incisors? (4)
Incisive papilla (upper anteriors 8-10mm anterior to the incisive papillae)
Alveolar ridge (upper incisors set buccal to and lower incisors should be set on the ridge)
Philtrum of the lip for the midline.
Resting lip line = Have 1-2mm incisal edge showing when the lips are at rest.
40
What 4 things make up the shade of teeth. ?
Value, chroma, hue and translucency.
41
Give the average horizontal bone loss for incisors post extraction
Incisors – 6.3mm,
42
Give the average horizontal bone loss for canines post extraction.
Canines – 8.5mm,
43
Give the average horizontal bone loss for premolars Post extraction.
10mm,
44
Give the average horizontal bone loss for molars post extraction
Molars – 12.8mm
45
What are the advantages of immediate dentures? (7)
Allows the patient to have dentures as soon as the extraction is carried out- allowing aesthetic & less psychological impact
Can act as haemorrhage control
Can reduce post-operative extraction pain as the socket is protected from the surrounding oral environment.
Maintains muscle tone
Helps with transitition to a denture.
Maintains OVD/ jaw relationship/ face height.
Maintain soft tissue and prevents soft tissue collapse..
46
What are the disadvantages of immediate dentures? (4)
* Will require a reline/rebae or remake of the denture witin 3-6 months (alveolar ridge will resorb - the denture no longer retentive and stable)
* Can be problematic fitting an immediate denture after a surgical extraction.
* Can be sore around the extraction site due to the tissue swelling.
* No trial stage prior
47
Write a prescription for special trays for upper and lower complete dentures
A- for alginate
B- for Medium bodied silicone.
A- ALGINATE
Please pour up primary impressions in 50:50 dental stone and plaster.
Please construction a custom tray in light cured acrylic resin (3mm spaced on upper) and (3mm spaced on lower) with an intra-oral handles stub handle on the midline.
B- Medium bodied silicone (Also for Polyether)
Please pour up primary impressions in 50:50 dental stone and plaster.
Please construction a custom tray in light cured acrylic resin (2mm spaced on upper) and (1mm spaced on lower) with intra-oral handles and a stub handle on the midline.
48
A 48-year-old male patient presents for the first time in your practise. He is otherwise fit and healthy and takes no medications. He also wears a complete upper denture which is 9 years old.
What is noticable about the patient’s palatal tissue? (2)
Erythematous, Papillary hyperplasia
49
A 48-year-old male patient presents for the first time in your practise. He is otherwise fit and healthy and takes no medications. He also wears a complete upper denture which is 9 years old.
What diagnosis would you make? (1)
Denture induced stomatitis - erythematous candidiasis
50
A 48-year-old male patient presents for the first time in your practise. He is otherwise fit and healthy and takes no medications. He also wears a complete upper denture which is 9 years old.
What would be your first line of treatment? (2)
Local measures:
**Denture care advice**
Brush the palate daily
Clean the dentures (Soak in Chlorohexidine or sodium hypochlorite if acrylic for 15 minutes twice a day)
Leave the dentures out as much as possible during treatment.
Remove denture at night & store it in water.
Clean with a dry tooth-brushing over a sink of water after each meal and at night,
If patinent uses an inhaler advise that they should rinse after inhaler use.
**Denture adjustment **
Ensure the dentures are adjusted (a loose/ ill fitting denture can make the problem worse)
We can use a temporary lining (tissue conditioner) on the fitting surface of the denture to prevent pressure on the infected gingivae until it heals. (e.g. Viscogel)
**Drug treatment**
If initial OHI & chlorohexidine doesn't work or patient is immunocompromised.
Good OH patient/ no dry mouth- Topical or systemic antifungal.
Dry mouth patient- topical antifungal (systemic should be avoided)
Immunocompromised- systemic antifungal + topical antifungal.
Topical- Miconazole oromucosal gel (20mg/g) applied after food 4 times daily.
Systemic- Fluconazole 7x 50mg capsules 1 daily.
Nystatin 30ml- used for when patient is on warfarin or statins (Fluconazole and miconazole contraindicated)
51
A 48-year-old male patient presents for the first time in your practise. He is otherwise fit and healthy and takes no medications. He also wears a complete upper denture which is 9 years old.
If this condition persists after first line of treatment what would be the next line of treatment to pursue?
Appropriate antifungal treatment
* Miconazole = 20mg/1g use: pea size 4x daily (after food) for 7 days
* Nystatin = oral suspension 30ml use: 1ml after food 4x daily for 7 days
Systemic:
* Fluconazole 50mg capsules use: 1x daily for 7 days
52
You decide to make a new denture. What instructions would you give to the lab technician regarding the construction of the upper special tray for the new master impression? (1)
Please construct a non-perforated special tray in light cured acrylic resin with;
- Xmm wax spacer
- handle: intra-oral = useful for complete and extra-oral useful for RPD
- intra-oral finger rests (anterior or posterior - cant use anterior if theres a handle present)
1. Alginate = 3mm wax spacer
2. Silicone/polyethers = upper 2mm (spaced) and lower 0.5-1mm (close fitting)
53
Give some causes of denture induced stomatitis?
Immunosuppressed, Poor dental hygiene, Dentures worn over night, Trauma from ill fitting dentures, Xerostomia.
Systemic steroids & broad spectrum antibiotics
54
What hygiene instruction would you give a patient with denture induced stomatitis? (5)
Leave dentures out as often as possible
Brush denture after every meal with soft brush (esp on fitting surface)
Take out at night time and leave in water overnight
Brush palate daily
Soak dentures for 15 minutes with-
Chlorohexidine mouthwash or sodium hypochlorite.
55
Your patient attends with denture induced stomatitis
Denture hygiene advice does not treat it.
What is the next line of treatment? (3)
Topical- Miconazole oromucosal gel (20mg/g) applied after food 4 times daily.
Systemic- Fluconazole 7x 50mg capsules 1 daily.
Nystatin 30ml- used for when patient is on warfarin or statins (Fluconazole and miconazole contraindicated)
Temporary reline (tissue conditoner) e.g. Viscogel / Coe-comfort
New dentures: when resolved denture induced stomatitis
56
How can we restore the excess freeway space with worn dentures? (2)
Occlusal pivots = Restore occlusal surface with auto-polymerising acrylic resin
57
You are shown a cast with an upper Co/Cr framework in place.
- What areas on the upper and lower that give support?
Tooth - The rests on the Co/Cr framework.
Tooth& Mucosa - Free end saddles ( or bounded where >3 teeth are replaced)
58
Define the Kennedy classifications
Class I- Bilateral free-end saddle
Class II- unilateral free end saddle
Class III- unilateral bounded saddle
Class IV- Anterior bounded saddle crossing the midline.
59
You are given a cast with an Co/Cr framework in place.
What function does the palatal extension provide.
It provides increased mucosal support by covering a larger surface area & creating a greater seal.
60
You are shown a cast with an upper Co/Cr framework in place.
Why do we place rests? (7)
Why do we place rest seats?
* To prevent movement of the RPD towards the mucosa
* Provide bracing on anterior teeth.
* For indirect retention
* determine axis of rotation for free end saddles
* To distribute the occlusal load
* To support the placement of clasps
* To Prevent the overeruption of unopposed teeth
prevents occlusal rests interfering with occlusion.
61
You are shown a cast with an upper Co/Cr framework in place.
There is also a rest seat on the 16. Why might this be placed.
* To prevent movement of the RPD towards the mucosa
* Provide bracing on anterior teeth.
* For indirect retention
* To distribute the occlusal load
* To support the placement of clasps
* To Prevent the overeruption of unopposed teeth
*
Is there a saddle area next to it?
62
You are shown a cast with an upper Co/Cr framework in place.
What different clasp options do we have for a premolar? (2)
Gingivally approaching clasp
gingivally approaching i-bar clasp?
RPI system- if supporting free end saddle
63
You are shown a cast with an upper Co/Cr framework in place.
What different clasp options do we have for a molar? (3)
Occlusally approaching single arm clasp (+ reciprocal arm)
Occlusally approaching Circumferential clasp (self reciprocating)
Occlusally approaching ring clasp.
64
You are shown a cast with an upper Co/Cr framework. The framework does not extend to the anteriors and has gingival margin clearance. What is the benefit of doing this? (2)
Relief of gingival margins::
Easier to clean the gingival tissues & causing less iritation.
Prevents food impaction.
65
Two Impression trays are given one with green stick on posterior saddles and one with Impression taken in alginate.
- What impression materials are used for primary impressions in complete denture cases? (2)
Impression compound- a non elastic impression compound material
useful for: very resorbed ridges and poor sulcus depth
Alginate- an elastic irreversible hydrocolloid impression material.
66
Two Impression trays are given one with green stick on posterior saddles and one with Impression taken in alginate.
Why would a tooth have Impression compound placed on it?
To record a single tooth crown preparation using greenstick and a copper ring technique.
67
Patient presents with loose old dentures causing denture stomatitis - What are the causes of denture stomatitis (5) and loose dentures?
Denture stomatitis-
* immunosuppression; diabetes, HIV
* Poor dental hygiene
* wearing dentures over night and not cleaning dentures appropriately
* Broad spectrum antibiotics
* oral steroids
Loose dentures?
Alv ridge resorption
Loss of muscle tone in face
68
what microbesa re involved in denture induced stomatitis?
Candida albicans
Candida glabrata (R for resistant to fluconazole)
69
You patient has attended with denture stomatitis.
Name 2 topical agents that can be used for treatment.
* Miconazole = 20mg/1g use: pea size 4x daily (after food) for 7 days
* Nystatin = oral suspension 30ml use: 1ml after food 4x daily for 7 days
* Chlorohexidine = 0.2% use 10ml 2x daily
SYSTEMIC
Glabrata resistant = * Fluconazole 50mg capsules use: 1x daily for 7 days
70
You have an asthmatic patient.
What might you see on the occlusal surface of the patients teeth, why is this and how can we treat it?
Erosion due using a steroid inhaler.
Advice: Rinse out after using your inhaler.
Treatment: Place fluoride varnish on the teeth to help protect them and reduce sensitivity.
71
Patient presents because they are unable to tolerate their new dentures.
They had their previous dentures for 20 years and the dentures have become loose over the last 18 months. This is why they were replaced.
What can be the differences between the old and new dentures?
Change in the extension of the flange.
Change in the post dam (palatal extension is different)
OVD.
Occlusion- over 20 years there will have been tooth wear on the denture
Path of insertion may have changed (if a partial denture)
72
Patient presents because they are unable to tolerate their new dentures.
They had their previous dentures for 20 years and the dentures have become loose over the last 18 months. This is why they were replaced.
What method could be used to make dentures that he could tolerate?
Replica technique
73
Patient presents because they are unable to tolerate their new dentures.
They had their previous dentures for 20 years and the dentures have become loose over the last 18 months. This is why they were replaced.
Name 2 methods the dentist can use to improve the fit of loose dentures?
Relining with
* a soft lining- e.g. soft heat cured acrylic- Relieves pain by replacing the missing mucosa (absorbing energy by deformation so decreases the energy absorbed by the tissues) e.g. COE-comfort/ Viscogel.
* A permanent lining- often for retention problems e.g. improving the post dam region for a peripheral seal. (uses a hard heat cured acrylic)
* Rebase- Replacement of the entire fitting surface.
74
Patient presents because they are unable to tolerate their new dentures.
They had their previous dentures for 20 years and the dentures have become loose over the last 18 months. This is why they were replaced.
Identify a feature that may cause problems on a patient’s palate
Palatal tori
Papillary hyperplasia- overgrown soft tissue on the palate.
75
A patient recently underwent an extraction of teeth 15 and 16. They arrive 3 months post extraction and request a cobalt chrome partial denture.
- What are the edentulous classifications for maxilla?
Atwood, Caldwell and Howell
I- Dentate
II- Post extraction (the teeth have just been taken out so you can see the socket)
III- Broad alveolar process (the ideal situation for our denture patients)
IV- Knife edge (can be painful for patients because the load goes on the knife edge part.
V- Flat ridge (no alveolar process)
VI- Submerged ridge (loss of basal bone causing an inverted ridge)
76
A patient recently underwent an extraction of teeth 15 and 16. They arrive 3 months post extraction and request a cobalt chrome partial denture.
The patient has all their other teeth.
Outline a design to replace the 15 and 16.
77
A patient recently underwent an extraction of teeth 15 and 16. They arrive 3 months post extraction and request a cobalt chrome partial denture.
Define retention
Resistance to displacement in a vertical direction.
78
A patient recently underwent an extraction of teeth 15 and 16. They arrive 3 months post extraction and request a cobalt chrome partial denture.
Define indirect retention.
Reistance to the rotational displacement of the denture.
79
A patient has the following missing teeth: 38, 37, 36, 35, 45 and 46. You decide to provide a definitive removable partial denture. The patient has a well maintained mouth with no active disease and you can assume has suitable survey lines.
What supporting components would you use? List the type, tooth (FDI) and surface.
| 2020 Paper1 (q6)
47 mesial occlusal rest
44 Distal Cingulum rest
43 Cingulum rest
34 MESIAL cingulum rest
Would the premolar not be occlusal rest ?
| Need to consider indirect retention aswell
80
A patient has the following missing teeth: 38, 37, 36, 35, 45 and 46. You decide to provide a definitive removable partial denture. The patient has a well maintained mouth with no active disease and you can assume has suitable survey lines.
2 List the retentive components that you would use. Indicate component name, what tooth (FDI) and position if appropriate. (3 marks)
| 2020 Paper1 Q6
* 34 gingivally approaching I bar clasp
* 44 gingivally approaching I bar clasp
* 47 self-reciprocating occlusally approaching clasp.
81
A patient has the following missing teeth: 38, 37, 36, 35, 45 and 46. You decide to provide a definitive removable partial denture. The patient has a well maintained mouth with no active disease and you can assume has suitable survey lines.
Name the major connector(s) and state the reasons for your choice including the choice of material. (3 marks)
| 2020 Paper1 Q6
Lingual bar
- Cover less of the mucosa
- Rigid
- Wide relief of gingival margins = easier to clean and prevent food impaction
- well tolerated
Material- Cobalt chromium.
82
A patient has the following missing teeth: 38, 37, 36, 35, 45 and 46. You decide to provide a definitive removable partial denture. The patient has a well maintained mouth with no active disease and you can assume has suitable survey lines.
Which feature of your design would provide indirect retention?
| 2020 Paper1 Q6
43 cingulum rest.
83
Patent presents requiring RPD with teeth present 34,33,32,31,41,42,43,44,47,48
What features provides indirect retention (5)
Major connectors
Minor connects
Rest seats
Saddle
Denture base
84
Patent presents requiring RPD with teeth present 34,33,32,31,41,42,43,44,47,48.
What major connector is chosen? describe requirements
A lingual bar made from cobalt chrome
(Assuming there is 8mm of gingival margin to the floor of the mouth to allow the major connector to be placed)
(3mm from gingival margin. 4mm for the width of the bar & it should be 1mm raised above the functional depth of the floor of the mouth.
85
When in function what features of an RPI prevent the denture from damaging the periodontium of the tooth.
Mesial rest acts as axis of rotation.
During occlusal load
The proximal plate and I-bar rotate downwards and mesially respectively around the axis of rotation
The I-bar and proximal plate disengage from the tooth/undercuts.
Thus, potential traumatic torque is avoided
86
Picture of a lower cast has 45, 44, 43, 41, 31, 32, 33, 34, 35, 38. Patient has an upper complete denture so there are no occlusal considerations
- What is the Kennedy classification?
Class II mod 2
87
Picture of a lower cast has 45, 44, 43, 41, 31, 32, 33, 34, 35, 38. Patient has an upper complete denture so there are no occlusal considerations
Describe the most likely design for a cobalt chrome denture
RPI system on the 45
Lingual bar connector (if 8mm clearance from the floor of the mouth to the gingival margin)
Suggestion:
support:
38 mesial occlusal rest
35 distal occlsual rest
41 cingulum rest
43 cingulum rest
45 mesial occlusal rest
retention:
38 self reciprocating/circumferential clasp
34 gingivally approaching clasp
45 gingivally approaching ibar clasp (RPI)
reciprocation:
34?
Major connector = lingual bar (Co-Cr)
88
Picture of a lower cast has 45, 44, 43, 41, 31, 32, 33, 34, 35, 38. Patient has an upper complete denture so there are no occlusal considerations
What is the axis of rotation when the denture is under load?
The mesial rest of the RPI provides the axis of rotation
A line created with the closest retainers to the saddle- the retainer adjacent and the retainer opposite.
89
Picture of a lower cast has 45, 44, 43, 41, 31, 32, 33, 34, 35, 38. Patient has an upper complete denture so there are no occlusal considerations
What would happen to the upper arch if the lower arch was not provided with a partial denture? (5)
This can cause combination syndrome.
where the natural lower teeth generate a lot of force against the edentulous maxillary ridge
What are the consequences?
- Trauma to the mucous membrane = ulceration and chronic pain/discomfort
- Instability = cannot achieved balanced occlusion with the lower natural teeth
= alveolar bone resorption and replacement with fibrous tissue
= poor retention and stability
Resulting in (features of combination)
1. Bone loss from the anterior part of the maxillary ridge.
2. Hypertrophy of the tuberosities
3. Papillary hyperplasia in the hard palate.
4. Extrusion of the mandibular anterior teeth
5. Bone loss under the denture base.
90
68 year old with partially dentate in upper and lower wearing upper and lower partial acrylic dentures. These are poorly fitting provided 2 years previously. On examination the upper does not seat fully in edentulous regions, with early to moderately deep primary carious cavities. Periodontal pockets greater than 3-4mm and minimal bleeding on probing but there is no peri-radicular radiolucencies. There are large radio-opacities in relation to the roots of several teeth. There is minimal periodontal bone loss, and he is on medication for Paget’s disease.
**Describe the anatomical changes, pathology and incidence behind the reason why the denture no longer fits?**
Paget's disease
Anatomical changes: We get new abnormally thick bone that is weak, brittle and deformed.
Pathology: disturbed bone turn over with an increase in bone remodelling (overactive osteoclasts causing more resorption) and to compensate the osteoblasts make excess bone that is deformed = deposition and resorption occurring at same time.
Consequences: bone swelling and enlargement = denture no longer fitting
Incidence:
Male
> 40
91
68 year old with partially dentate in upper and lower wearing upper and lower partial acrylic dentures. These are poorly fitting provided 2 years previously. On examination the upper does not seat fully in edentulous regions, with early to moderately deep primary carious cavities. Periodontal pockets greater than 3-4mm and minimal bleeding on probing but there is no peri-radicular radiolucencies. There are large radio-opacities in relation to the roots of several teeth. There is minimal periodontal bone loss, and he is on medication for Paget’s disease.
**Why could Arthur develop dental caries?** (4)
Because the denture does not seat fully it means that the clasps are not engaging the correct area of the tooth/undercuts and this can act as a food/plaque trap = allowing bacteria to sit against the teeth and produce acid = demineralise and cause caries
Patient will be treated using bisphosphonates and Xerostomia is one of the side effects = increased risk
Reduced manual dexterity due to his age (Reducing OH)
If he has a carious diet
92
68 year old with partially dentate in upper and lower wearing upper and lower partial acrylic dentures. These are poorly fitting provided 2 years previously. On examination the upper does not seat fully in edentulous regions, with early to moderately deep primary carious cavities. Periodontal pockets greater than 3-4mm and minimal bleeding on probing but there is no peri-radicular radiolucencies. There are large radio-opacities in relation to the roots of several teeth. There is minimal periodontal bone loss, and he is on medication for Paget’s disease.
**Account for the most likely cause of the radio-opacities on the radiographs**?
Hypercementosis of the roots caused by Paget's disease.
(makes the teeth more difficult to extract)
93
68 year old with partially dentate in upper and lower wearing upper and lower partial acrylic dentures. These are poorly fitting provided 2 years previously. On examination the upper does not seat fully in edentulous regions, with early to moderately deep primary carious cavities. Periodontal pockets greater than 3-4mm and minimal bleeding on probing but there is no peri-radicular radiolucencies. There are large radio-opacities in relation to the roots of several teeth. There is minimal periodontal bone loss, and he is on medication for Paget’s disease.
**How are you going to manage his clinical care?
Describe the treatment you would provide and treatment you would seek to avoid?** (7)
We will manage:
Prevention:
OHI (Toothbrushing/ Interdental cleaning/Fluoride use)
Diet advice
Disease control:
Perio:
BSP S3 step 1= Education, OHI, risk factor management, PMRP, 6 point pocket chart Plaque and gingival scores.
Caries:
Caries removal and restore
May need RCT if caries is extensive.
New dentures- Need to inform the patient that they will have to be frequently remade due to Paget's.
Monitor:
More prone to malignancy = osteosarcoma (this is more common In young so when symptoms occur in older patients consider padgets)
Treatment you would seek to avoid = Extractions
Go through Osteolytic and osteoscleroitic phases
- During osteolytic phase = bleed a lot after XLA
- During osteoscleroitic phase = dense and harder to XLA = more prone to dry socket
- risk of Medication Related Osteonecrosis of the jaw as they are on bisphosphonates
- more prone to infection
They should be referred to a specialist for this treatment.
We need to regularly monitor this patient & Reassess.
94
68 year old with partially dentate in upper and lower wearing upper and lower partial acrylic dentures. These are poorly fitting provided 2 years previously. On examination the upper does not seat fully in edentulous regions, with early to moderately deep primary carious cavities. Periodontal pockets greater than 3-4mm and minimal bleeding on probing but there is no peri-radicular radiolucencies. There are large radio-opacities in relation to the roots of several teeth. There is minimal periodontal bone loss, and he is on medication for Paget’s disease.
**You decide he requires an extraction of lower molar which does not have a radio- opacity associated with its root and you are aware he is on bisphosphonates.
What precautions would you take when you extract the tooth?**
We want to find out more about his bisphosphonates:
Whys is the patient taking them?
LR = treatment/prevention for osteoporosis or non-malignant bone diseases (lower dose)
HR = treatment of symptoms and complications of metastatic bone disease (breast, prostate or multiple myeloma) (higher dose)
Route of administration
- Are they oral or IV?
Same risk for both
How long has the patient been taking them for?
HR = taking for >5 years
What medications does the patient take alongside their bisphosphonates?
HR = glucocorticoids even if used for < 5 years
HR = anti-resorptive or anti-angiogenic used together or in a patient with a HX of bisphosphonates
Have they previously had MRONJ?
YES = HR
Precautions:
If patient low risk-Discuss risks/ benefits then continue with treatment.
No prophylaxis required
Discuss risks and benefit with patient Ask the patient to contact the practice if they have any concerns (unexpected pain/ tingling/ numbness/ altered sensation/ swelling in the extraction area.
Ensure you review the socket at 8 weeks. (If it has not healed- refer to specialist)
If patient is high risk - explore all alternative tx options (don't impact the bone) and consult a specialist re treatment planning.
No prophylaxis required
Discuss risks and benefit with patient Ask the patient to contact the practice if they have any concerns (unexpected pain/ tingling/ numbness/ altered sensation/ swelling in the extraction area.
Ensure you review the socket at 8 weeks. (If it has not healed- refer to specialist)
95
85 year old complaining of generalised pain underneath lower complete denture on left side. She is edentulous in maxillary arch and successfully wears a complete upper denture. Her denture has become progressively loose during the last 2 years, on examination you reckon there is an unerupted sound 2nd premolar that is now partially visible.
The patient is on bisphosphonate medication for her osteoporosis.
You decide with oral surgeon that the tooth should remain in situ. Outline your approach for the design of a replacement lower denture that would be stable and comfortable in function?
1. Check the denture is retentive/ has sufficient support and stability
2. Check occlusion.
3. In jaw registration stage we are checking the RVD/ OVD/ FWS and neutral zone.
4. Get the patient to decide their tooth shade & shape
5. Check extension- so that it does not impinge on frenal attachments or the neutral zone .
6. Place a relief in the region of the 2nd molar (leaves space for the application of a soft lining material under the area of the premolar)
96
- Give 4 advantages of a CoCr denture base?
- Higher dimensional stability compared with acrylic which means it will not change shape easily
- It is more stable and retentive material
- High thermal conductivity which allows patient to feel temperature = natural feel
- More hygienic as it is less porous which decreases accumulation of food, plaque and calculus and makes it more sesisatnt to candida
- Can be cast thinner while maintains strength
- strong and rigid in cross section
- can incorporate metal rests into the framework
97
give 2 disadvantages of a cobalt chrome denture base
o More expensive material than acrylic
o More difficult to add teeth into denture compared with acrylic types (Denture additions)
98
What undercuts are required for Stainless steel, Gold and CoCr clasp?
SS = 0.75mm
Gold = 0.5mm
Co-Cr = 0.25mm
99
How can you check stability clinically?
Apply axial load to the occlusal surface & try to rock the denture from side to side.
100
List the features of a complete denture you check at try in stage?
o Extensions – (pull tissues- underextended/ maniupulate tissues= over extended.
o Retention- hold out tissues and see if the denture drops
o Stability- Does it rock from side. toside.
o Occlusal plane (posterior plane parallel to ala-tragus line and anterior plane parallel to inter-pupillary line)
o Occlusion (RVD, OVD and FWS)
Clicking noises =OVD too big (Not enough FWS so dentures click) Whistling noises= OVD too small (FWS too large)
o Appearance (ensure colour of teeth and gingivae are age appropriate)
o Speech (phonetic tests)
o Patient opinion
101
What is the implication of using impression compound for the impression of the arch.
Used in partial dentures to take an impression of the saddle area.
Used in complete dentures as an impression material or to extend the impression tray.
102
Two Impression trays are given one with green stick on posterior saddles and one with Impression taken in alginate.
What stage is this?
Primary impressions.
Master impressions would be with the special trays.
103
3 local factor for candida albicans (3)
broad spectrum antibiotics use
Local corticosteroid use e.g. asthmatic using inhaler without rinsing mouth out
poor OH/dentrue hygiene (wear at night)
Xerostomia
2 medical:
Diabetes Mellitus
HIV
Immunodeficiency
immunocompromised
smoking
Radiation exposure
104
4 management factors for candida albicans (4)
* Chlorhexidine rinse x2 daily (0.2%), Denture Hygiene- remove at night/soak in CHX for 15 minutes.
* Temporary tissue lining (tissue conditioner- to reduce inflammation),
* Antifungals (Miconazole/ fluconazole), Smoking cessation,
* Rinse after inhaler use
105
Patient has denture stomatitis & asthma.
What will be seen on the occlusal surfaces of the teeth and what can we do about it in the short term.
* Erosion due to inhaler - acidic steroid inhaler, xerostomia from use
* Advise patient to Rinse mouth out after use
* use a spacer device
* F varnish
106
The illustration above is of an upper edentulous ridge. Please identify the anatomical landmarks indicated. (3 marks)
| 2020 PAPER 1 Q7
A- incisive papilla
B- Maxillary tuberosity
C-palatine fovea
107
3 How do you achieve adequate retention in a conventional complete upper denture? (4)
| 2020 paper 1 Q7
- Distal border of the denture extending onto the hamular notch (unsure)
- Extending the denture flanges to the depths of the functional sulcus
- Incorporation of a post dam.
- denture boarder not interfere with muscle attachments
108
Complete dentures:
In terms of biometric principles where are denture teeth located on?
A-Upper denture
B- lower denture
Upper denture
Buccally to the ridge (8-10mm anterior of incisive papilla)
= promotes denture stability
Lower denture
Teeth set directly over the ridge.
= ensures the palatal cusps of the upper molars occlude the fissures of the lower molars and the forces are appropriately directed.
= ensures no tongue restriction
