Prosthodontics Flashcards
what is kennedy class 1
bilateral free end saddle
what is kennedy class 2
unilateral free end saddle
what is kennedy class 3
bounded saddle
what is kennedy class 4
anterior bounded saddle crossing midline
what is craddock class 1
tooth borne
what is craddock class 2
mucosa borne
what is craddock class 3
combination of tooth and mucosa borne
what is the definition of retention
resistance of the denture to vertical displacement
what are the methods of retention
clasps
soft tissue undercuts
adhesion
friction
path of insertion
precision attachments/implants
what is the definition of indirect retention
resistance to rotational displacement
what does reciprocation do
prevent a clasp arm moving the clasped tooth
what is the function of bracing
stop the denture moving laterally
name the types of upper major connectors and advantages of them
strap - doesnt interfere with tongue
ring - stays away from gingival margin
horseshoe - keeps palate clear
questions to ask in a denture history
why were teeth lost
how long have they worn dentures for
how many dentures have they had
have they got a favourite denture
have they got a preferred design
which do they prefer
what to examine extraorally on a denture patient
lower facial height
naso-labial angle
facial support
smile line
aesthetics of existing dentures
abnormalities
limited opening
what is the definition of support
the resistance to vertical movement of the denture towards the tissue
what is the definition of stability
the resistance to horizontal (lateral) movement of the denture
disadvantage of a simple hinge articulator
cannot reproduce the movements of the mandible
what are the requirements of an articulator
post must be on the incisal table
incisal post should be at 0 degrees
casts must be able to be easily separated from the bases
purpose of a surveyor
identify, analyse and mark the maximum contours of tooth and tissue surfaces of dental casts for the fabrication of removable partial dentures
establish a suitable path of insertion which utilises guide surfaces on the teeth to provide long term retention
what is the process of surveying
place cast on the table of the surveyor with occlusal plane horizontal
tripod the cast
use the analysing rod to look for undercuts
use the graphite to mark the undercuts
decide where path of insertion and removal will be and mark this in red
how long must a CoCr clasp be and why depth of undercut does this engage
15mm long
engaging a 0.25mm undercut
undercut gauge for cast gold alloy
0.5mm
undercut gauge for wrought stainless steel clasp
0.75mm
what are guide planes
2 or more parallel axial surfaces on abutment teeth which limit the path of insertion of a denture
can be naturally occurring or may need prepared
what do guide planes provide
increased stability
reciprocation
prevention of clasp deformation
improved appearance
when would you not use a polyether (impregum) impression material
in severe undercuts
why do you need to record the occlusion when making dentures
know the position of teeth in relation to each other
know what is normal for the patient and keep it the same
if planning to change occlusion
facilitate denture design
ensure loading forces are applied correctly to teeth and underlying mucosa
help the technician set up the teeth
ensure the denture is stable and not dislodged in function
what is freeway space
space between the occluding surfaces of the maxillary and mandibular teeth when the mandible is in physiologic resting position
what problems cause displacement of record blocks
overextension of the peripheries
too much lip support
what does LIMBO stand for
lip support
incisal level
midline
buccal corridor
occlusal plane
how much tooth should someone show on rest
1-2mm
depends on age
what is the neutral zone
the space between the lips and cheeks on one side and the tongue on the other side where the forces between the tongue and cheeks are equal
what is the normal freeway space
2-4mm
how do you measure the freeway space
RVD - OVD = FWS
what do you look at at a denture try in before it is in the mouth
are the bases stable on the cast
are the borders smooth
is the extension shaped to the depth and width of the functional sulcus
is wax distorted or well adapted
check occlusion for even contacts
is there an AOB
are the centre lines coincident
is the pin on the table
what do you check at a denture try in
retention and stability
base extension
speech
aesthetics
how do you assess the base extension of a denture
hold tissues away from denture and see if it drops
how do you assess speech with a denture
listen for fricatives
count from 60-70
F and V sounds
what is the problem and how do you fix if at a denture try in the teeth are contacting during speech
insufficient FWS so OVD needs reduced
re-register at new OVD then ask lab for remount and re-try
what is the problem and how do you fix if at a denture try in there is significant whistling sounds during s sounds
air is escaping too much
OVD may need to be increased or the anterior tooth position changes
re-register at new OVD and ask lab for remount and re-try
if the OVD has been increased by accident how do you fix this
teeth need to be removed from one or both dentures and replaced with a wax rim
if the OVD has been decreased by accident how do you fix this
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
what do you check at insertion stage of denture making
retention and stability
base extensions
LIMBO
position of teeth
FWS
contacts in RCP
speech and aesthetics
discomfort
insert and remove
what are the instructions to give a patient about wearing a denture
may take time to adjust
some discomfort normal
speech may lisp
eating may be difficult
wear as much as possible
what are the common areas for denture trauma to occur
lingual frenum
mylohyoid ridge
undercuts
what factors contribute to poor denture hygiene
poor manual dexterity
inability to self care
xerostomia
poor diet
old worn dentures
lack of oral health knowledge
wearing dentures full time
ill-fitting dentures
poor neuromuscular control
what are the effects of poor denture hygiene
caries
periodontal disease
denture stomatitis
halitosis
pain
what should you advise patients to clean their denture with
soap and soft brush
then chemical soaking
what type of denture cleansing tablet is most commonly used and is safe for both acrylic and chrome dentures
alkaline peroxides
- sterodent
what type of denture cleansing material is not suitable for chrome dentures due to its corrosive properties
alkaline hypochlorites
- milton
what advice is given to patient about denture hygiene regime
brush dentures daily (after every meal, over basin, no toothpaste as it will scratch it)
soak dentures daily (20mins every evening)
leave dentures out at night (warn about stomatitis risks)
visit dentist regularly
what are the advantages of using impression compound instead of alginate
good for gagging patients
rapid working time
seconds rather than minutes
what do you look at when assessing an impression
are all the edentulous areas included
are the sulci areas ton be included in the denture recorded fully
are deficiencies present due to air inclusion
is the impression fit for purpose or not
what are the advantages of special trays
accurate peripheral extension
uniform thickness of material
reduced amount of material
what does placing stops of greenstick on special trays allow for
positioning
maintaining space for material
allow consistent placing of tray
