Prosthodontics Flashcards
(44 cards)
What are the indications for replacement of missing teeth?
to improve masticatory efficiency to improve speech preserve or improve oral health by preventing movement of teeth improve distribution of occlusal loads space maintenance restore aesthetics prepare patient for complete denture
What are the treatment options for replacement of missing teeth?
No replacement bridges (resin retained, conventional) implant supported prosthesis removable partial dentures complete immediate denture complete dentures
What are the components of a bridge?
Bridge - prosthodontic appliance definitively attached to remaining teeth and replaces the missing tooth/teeth
abutment - tooth providing support for bridge
retainer - component cemented on to abutment to provide retention. can be full/ 3quarter covereage crown, post retained, onlay, inlay
pontic - artificial tooth suspended from abutments
connector - component joining pontic to retainer
saddle - area of edentulous ridge
units - pontics + retainers
retention - prevents removal along path of insertion
support - ability to bear occlusal load
resistance - prevents dislodgement in apical or oblique directions
What are the different types of bridge?
Fixed - Fixed
fixed - movable
direct - cantilever (one end only)
resin bonded
removable
What are reasons for a bridge failing?
loss of retention, mechanical failure, problems with abutments.
What are classifications of edentulous ridges?
Kennedy I - bilateral free end saddle
II - unilateral free end saddle
III - unilateral bounded saddle
IV - unilateral bounder saddle which crosses the midline only
classes I-III can have modifications. classify by most posterior saddle only
What are the steps involved in designing partial dentures?
Outline saddles plan support obtain retention assess bracing choose connector
What are the laboratory stages in designing a denture?
primary impressions and occlusion -> special trays (design, survey and tooth preparation) Master impressions ->tooth trial (take shade and mould) try in CoCr frame Wax try in delivery
With complete dentures - what is retention and what is it dependent on?
resistance of displacement. dependent on peripheral seal contact area between denture and tissues close fit viscosity and volume of saliva
With complete dentures - what is stability and what is it dependent on?
ability of the denture to resist displacing forces during function. supporting tissues and the forces acting on the polished and occlusal surfaaces
What is the neutral zone?
where muscular displacing forces are in balanced. the ideal zone for the denture to be placed
List three special impression techniques and when they are used
neutral zone impression techniques - when patients have limited natural retention for full lower
flabby ridge technique when patient has compressible ridge on upper anteriors - common when edentulous upper and natural lower
functional impression - tissue conditioner is placed on pt dentures, and they wear their dentures for several days
how do you modify wax rims and record occlusion?
trim rim to give correct naso-labial angle
trim anterior to give correct height regarding lip line
trim occlusal plane - parallel to ala-tragus line
mark centre line, canine line and smile line
What denture hygiene advice would you give a patient?
remove dentures at night and store in water
clean after every meal with a toothbrush and soap over a full sink
once a week use denture cleaner
What are common denture complaints and what are they caused by?
pain - can be roughness, poor OVD, occlusion problems, pathology, RR, exposed foramin
Loose - poor peripheral extension, teeth not in neutral zone, unbalanced articulation, inadequate saliva, poor ridge form, cant adapt
burning mouth - sensitivity to acrylic, candidiasis, xerostomia, psychological conditions
speech - (f and v - incisors palatally placed), (dst - incorrect OJ and OB), (s becomes th - palate too thick), (whistling - palatal vault too high), clicking - OVD or poor retention
cheek biting - teeth not in neutral zone
retching
recurrent # - carelessness, occlusal faults, fatigue, flexing of denture from tori
What is denture stomatitis and how do you manage it?
it is a common condition associated with candida albicans infection. Appears as redness under the denture bearing area. increased in incidence if you have f/f, F>M
generally caused by poor denture hygiene and wearing dentures over night. systemic problems can predispose - haematinic deficiencies, diabetes, steroids, drugs, xerostomia, high sugar intake
Manage with good denture hygiene, mechanical and chemical cleaning - can use stearadent. modify aetiological factors.
miconazole gel to fitting surface
When would you provide a copy denture?
cant adapt
changing the worn occlusion when fit surface is good
denture has been bleached/discoloured but rest is good
pt wants a spare
When would you provide an over denture?
-/F or free end saddles so increase stability and reduce retention
CLP
hypodontia
severe tooth wear
What is osseointegration?
A direct functional and structural connection between a load carrying titanium implant with the cone with no intervening CT
Why is tooth support useful in a partial denture?
under load the compressible tissues can move 500um under 4 newtons, whereas teeth move 20um - significantly less compression of the tissues, less movement and increased comfort
How would you design a rest seat on a tooth?
Rest seat must be able to direct foce down long axis of tooth
basin shaped to allow some rotation
deep enough to allow for metal to not interfere with occlusion - 0.5mm on occlusal surface, 1mm reduction in marginal ridge
What features of an RPD give indirect retention?
the incisal rests which are 90 degrees to clasp axis
what major connector would you use for a lower RPD and why?
lingual bar, CoCr.
material offers retention and stability
well tolerated
free of gingival margins
17 y/o with congenitally missing 22/23. what options for treatment are there?
implants RPD bridge (4 units, fixed/fixed) ortho combined ortho and restorative
