Pros Flashcards
What does RPI stand for
Rest on mesial surface
Proximal plate distally
Gingivally approaching I bar Clasp
Mechanism of action for RPI
Mesial rest acts as axis of rotation.
Proximal plate rotates downwards, I bar clasp rotates mesially around axis of rotation.
During occlusal loadplate and clasp disengage from tooth/ undercuts .:. preventing potentially traumatic torque.
How would you assess the position of an unknown unerupted tooth?
would use separate radiographic views
opt and PA/ occlusal
Use SLOB rule w/ parallax technique
same lingual, opposite buccal
wherein if the object moves same way as tube shift is lingually placed
XLA Risks pt with osteoporosis (6)
pain swelling bruising infection mandibular fracture MRONJ Dry socket Nerve damage
Outline your approach for an overdenture with a partially erupted tooth (12)
retention stability support occlusion- fws, ovd, rvd extension appearance - shade and mould neutral zone relief for p.e tooth soft lining
Measurements required for lingual bar
8mm
4mm height
3mm from gingival margin
1mm from base of functional sulcus of FoM
Name the method of producing dentures of same specs to old dentures
Replica technique
Methods of adjusting fit of current dentures
Reline
Rebase
Remake
Factors needing checked at try in stage
midline occlusion shade + mould of teeth position of teeth lip support extension canine line incisal line buccal corridors pt opinion
Define retention
Resistance to vertical displacing forces
Define stability
Resistance to horizontal displacement
Name 3 ways in which an upper complete denture is retained
Muscular
Adhesion/Cohesion
Peripheral/ marginal seal, post dam
What is meant by biometric guidance of tooth placement
Teeth to be placed in pre-extraction sites
Maxillary teeth placed buccally to ridge
Mandibular teeth placed on ridge - .:. palatal cusps of U teeth occlude with fossa of L teeth
- allows appr. force displacement
- reduces tongue restriction for lowers when placed on ridge
aetiology of denture stomatitis (3)
tx (6)
poor denture hygiene- .:. fungal infection + plaque accumulation
leaving dentures in at night
immunocompromised pt
denture hygiene instruction tissue conditioner CHX MW antifungal agent prescribed new dentures when health restored
How do you restore freeway space in worn dentures?
occlusal pivots
restore occlusal surface with autopolymerising acrylic resin
What problem can occur with a complete upper denture occluding with partial lower denture?
why does this occur
combination syndrome resulting in flabby ridge
forces direct on upper anterior region leading to excessive and rapid alveolar bone loss in region, this is replaced by excess FIBROUS tissue
How would you fabricate dentures for a pt with flabby ridge? (2 techniques)
need mucostatic impression techniques to record ridge at rest
- 2 stage impression technique
1st imp taken in medium body PVS, cut out material around area of FR. 2nd imp taken in light bodied PVS - window technique- window cut out of impression tray to allow for flow of impression material0 leaving ridge undisplaced
Define Kennedy Class 2 Mod 1
Unlateral free-end saddle, with one bounded saddle
Define Kennedy Class 4
bounded saddle crossing midline
Define Kennedy Class 1 Mod 2
Bilateral free-end saddles, with one bounded saddle
Define Kennedy Class 3 Mod 1
two bounded saddles
System of design for partial dentures
outline saddle areas support retention stability reciprocation connector
OSRSRC
Give 2 max and 2 mand connectors, with pros and cons
maxillary plate/strap :) thin :( large palatal coverage
maxillary bar :) less mucosal coverage :( thick
lingual bar :) away from gingiva :( not well tolerated
lingual plate :) thin- better tolerated :( difficult to keep clean
Define support
Resistance to occlusally directed loads
Define indirect retention
how is it provided
Resistance to rotational displacement forces.
provided by supporting components
e.g a rest used to prevent distovertical rotational displacement forces. usually placed 90 degree from axis of rotation. Used in cases of free end saddles.
Give 3 types and examples of retentive factors
Mechanical - clasps/ guide planes
Muscular - buccinator, obicularis oris
Physical - cohesion/ adhesion
Name and describe classification for ridges.
Alwood and Howell’s
I. Dentate II. Post- XLA III. Broad IV. Knife edge V. Flat VI. Submerged
What is a knife edge ridge
where rapid resorption of the buccal and lingual alveolar bone has resulted in hard bony presentation with thin layer of gingiva overlying
Give 3 reasons for a knife edge ridge
immediate dentures
periodontitis pre XLA
traumatic surgery to XLA
How to manage a knife edge ridge in dentures
soft liner
SURGICAL REMOVAL of bony prominences
What is the difference between soft liner and tissue conditioner?
soft liner- used for healthy gingiva as cushioning/shock absorber in relines or in cases of knife edge ridge/bony prominences
tissue conditioner- used in unhealthy/ulcerated gingiva to aid healing and dissipate load
What is a functional impression?
where tissue conditioner applied to denture, pt to wear denture 24 hours in function. brings back and sent to lab for reline
how to check retention clinically
pull on premolar region to see if displacement
push on anteriors to test post dam
how to improve retention of dentures (not remaking)
reline
rebase
implant retention
precision attachments (if partials)
Describe process of making copy denture
consent & explain
clean & sterilise dentures
need 2x large stock trays per denture
apply adhesive to inside surface of one tray, outside of other.
mix lab putty. apply to inside of first tray and lay denture occlusally down onto putty. mould putty up within 2mm of denture edge
place VASELINE AND LOCATION NOTCHES to aid removal
apply putty to fitting surface of denture and place 2nd stock tray outside surface down onto this
bind and allow to set
remove dentures, clean, return to pt
send to lab for wax copies
can use as master impressions, take with light bodied PVS, take jaw reg here too.
carry on as normal after
label features of mand and max
in onenote doc ‘important’
Signs and symptoms of an incorrect OVD (5)
tmd aggravation
pain mandibular muscles
clicking when eating
occlusal wear in RPD
Microbe involved in denture stomatitis
give 5 virulence factors of this microbe
candida albicans
germ tube formation extracellular enzymes adhesion acidic phenotype switching
Tx plan for denture stomatitis
denture hygiene advice: remove at night, clean with toothbrush over sink of water, soak for 20mins in alkaline peroxide/sterodent, then store in water overnight
antifungal meds:
topical: miconazole, nystatin, CHX
systemic: fluconazole, itraconazole
Where should your post dam be?
hamular notch to hamular notch
along vibrating line - junction of hard and soft palate
1-2mm in front of palatine fovea
What is the distal extension of a lower complete denture?
2/3rd RETROMOLAR PAD
Why is the buccal shelf used for support?
non-resorbable
What anatomical features can you use to set the incisors?
incisive papilla- 1cm anterior to
philtrum- use as midline
lip line at rest - incisal edge should show 1-2mm when lip at rest
What 4 variables make up the shade?
value
chroma
hue
translucency
Give the average horizontal bone loss for
a) incisors
b) canines
c) premolars
d) molars
6
9
10
13
Advantages of immediate dentures?
pt aesthetics and psychological benefit maintain face height provide lip support prevent soft tissue collapse transitional aid haemorrhage control
Disadvantages of immediate dentures?
fit poor due to resorption
need relining or rebasing
no trial stage
difficult with surgical xla
Write a prescription for special trays for U and L complete dentures
Please construct U and L special trays in light cure acrylic. Upper with 2mm spacer and extraoral handle. Lower with 1mm spacer and intraoral handle and finger rests in premolar region.
define: reciprocation
a plate or non-engaging clasp arm that can resist the force placed on tooth during seating of denture.
resisiting tip action of clasp moving over bulbosity during seating motion.
rpd is passive once seated but active during seating
3 possible disadvantages of giving a pt an RPD
plaque trap - > enhanced prevention
clasps impinge on aesthetic zone - > need sensitive denture design
denture stomatitis - > denture hygiene advice
ideal craddock classification and why?
any negatives of this classification
tooth borne
occlusal load transmitted through pdl protects mucosa from trauma greater support greater retention more comfortable improved stability
:( expensive + difficult to modify
effects of loss of teeth
function -
- mastication difficult as loss of teeth affects posselts envelope, icp lost - speech - sibilant sounds rely on tooth contact
dentition
- drifting
- loss of lip support
- loss of alveolar bone
general
- eating
- aesthetics
- psychological impact
indications for tooth and mucosa bourne
- free end saddles - reduced number of teeth
- 3+ missing teeth in one area- large saddles
