RPD Flashcards
EFFECTS OF TOOTH LOSS
alveolar resorption, tooth movement (drift), speaking effected (F sounds if anterior)
WHICH CRADDOCK CLASS WOULD A FREE END SADDLE BE
3 - both : as no teeth only mucosa at one end
WHAT ARE THE ONLY TEETH THAT CAN HAVE OCCLUSALLY APPROACHING CLASPS
molars
WHAT DISEASES CAN EFFECT DENTURES
rheumatoid arthritis - in/out
osteoporosis/ bisphosphonates - careful when planning extraction
xerostomia - need saliva to retain and makes uncomfy
neuromuscular disease - Parkinson’s - hard to retain
Mucosal disease
WHAT SHOULD YOU LOOK FOR WHEN EXAMINING INTRA-ORALLY FOR DENTURE PATIENT
residual ridges, mouth health, state of abutment teeth, missing teeth, soft tissues, denture bearing area, denture stomatitis
DEFINE SUPPORT
The resistance of the denture to occlusally directed load - what stops denture moving towards soft tissues - rests
DEFINE RETENTION
Resistance of denture to vertical displacement - lifting away from tissues and falling out - clasps
DEFINE INDIRECT RETENTION
resistance to rotational displacement
WHAT TO LOOK FOR WHEN ASSESSING SMILE
lip support smile line does occlusion line up state of teeth shade/ size/ shape visible denture components buccal corridors
CAUSES OF DENTURE STOMATITIS
continuous denture wearing, keeping in overnight, not washing them properly/regularly, salivary flow low, material, age of denture, smoking, diet, plaque pH
NEWTONS TYPE 1
Localised inflam, reasonable OH but dont remove denture at night
NEWTONS TYPE 2
Diffuse erythema involv part/all denture bearing area
NEWTONS TYPE 3
Long standing, inflammatory papillary hyperplasia
WHICH FUNGI CAUSES DENTURE STOMATITIS
CANDIDA ALBICANS
WHAT ARE STOCK TRAYS USED FOR
primary impressions only as they are standardised sizes so when we dont require precison
WHAT IS RED RIBBON WAX USED FOR
adjusting stock trays in primary impressions
WHEN IS COMPOUND MATERIAL USED
impressions
underneath alginate in free end saddles
mainly in mandible lingually
WHERE TO STAND WHEN TAKING UPPER IMPRESSION
behind
WHERE TO STAND WHEN TAKING LOWER IMPRESION
in front
HOW TO REMOVE IMPRESSIONS
finger into buccal sulcus
WHAT TO DO AFTER TAKING IMPRESSION
disinfect in perform 10 min
inspect
labelled bag w wet paper towel
WHY PUT AN IMPRESSION INTO BAG WITH WET PAPER TOWEL
so it doesn’t dry out and cause dimensional changes
WHAT DOES THE LAB DO WITH PRIMARY IMPRESSIONS
pour them into study casts
WHAT ARE THE 3 TYPES OF GYPSUM AND THEIR PROPERTIES
- plaster - large irregular particles
- stone - small reg
- improved dental stone - small reg w chemicals to reduce expansion
HOW MUCH WATER USED FOR EACH TYPE OF GYPSUM
- plaster = 50ml
- stone = 25ml
- improved stone = 20ml
WHAT IS DENSITE
improved dental stone
WHICH MATERIAL IS USUALLY USED FOR STUDY CASTS
dental stone
WHAT DO YOU WRITE ON THE LAB CARD AFTER PRIMARY IMPRESSIONS
my name patient name patient unit number tick that cross infection procedures have been followed which material you want casts poured in ask for individual (custom) trays, PU/PI light cure acrylic with wax spacer and extraoral handle date of next appointment signature of supervising clinician
WHEN WOULD YOU DO A JAW REGISTRATION
primary jaw registration - when cant hand articulate casts
after final impressions
WHEN DO YOU USE WAX WAFER
during jaw registration between the casts to see if teeth meet during jaw registration
WHAT POSITION DO YOU REGISTER THE JAW IN
intercuspal (ICP)
WHEN ARE PRIMARY RECORD BLOCKS REQUIRED
when the casts cannot be hand articulated
WHY WOULD THE JAW REGISTRATION BE INACCURATE WHEN USING PRIMARY RECORD BLOCKS
not enough wax removed in saddle areas
too much registration medium used
WHAT ARE THE CONSEQUENCES WHEN JAW REISTRATION IS INNACURATE
inaccurate vertical dimension
no freeway space
mounted inaccurately
DIFFERENCE BETWEEN OVD AND RVD
occlusal vertical dimension is with the teeth in occlusion and resting vertical dimension they aren’t, RVD has freeway space
METHOD OF MEASURING OVD / RVD
mark dot on non-moving areas on chin and nose and the use a protractor to then measure with a ruler the distance between them
HOW ARE PRIMARY RECORD BLOCKS MADE
Record OVD
try in upper record block and adjust
same with lower
both in and measure OVD - should be same
WHAT IS AN ARTICULATOR
metal hinged device which lets you reproduce movements of the two jaws in relation to eachother, represents TMJ and both jaws
WHICH POSITION SHOULD CASTS BE MOUNTED IN
ICP - arbitrary position
WHAT IS A SURVEYOR
paralleling instrument to identify, analyse and mark max contours of teet and soft tissues for dental casts
WHAT IS THE AIM OF A SURVEYOR
to establish suitable path of insertion
WHAT IS THE PATH OF DISPLACEMENT
the path at which the denture is dislodged by food
commonly at 90 derees to occlusal plane
WHAT IS THE PATH OF INSERTION/REMOVAL
the path that the denture will be removed and inserted into the mouth
path from denture first contact with the teeth to it being fully seated
common or altered
WHY DO YOU USE TRIPOD LINES WHEN SURVEYING
so the POI/R can be relocated at a separate time
HOW IS A GRAPHITE MARKER USED
with tip at gingival margin
WHAT DOES THE SURVEY LINE SHOW
the extend of the undercut
line is at the bulbosity
WHAT CAN YOU DO WITH UNDERCUTS
use / eliminate by blocking out or altering POI
WHAT ARE ADVANTAGES OF ALTERING THE POI
eliminate undercuts
provide retention
improve appearance by closing gaps
HOW DOES ALTERING THE POI INCREASE RETENTION
guide planes are different to the POD
HOW MUCH OF THE CLASP WILL ENGAGE THE UNDERCUT AND WHY
final third - so it can flex on and off
WHAT ARE THE 3 UNDERCUT GAUGES
CoCr = 0.25mm
wrought stainless steel = 0.5mm
gold = 0.75mm
WHAT STEPS SHOULD BE DONE BEFORE STARTING RPD DESIGN
initial assessment and convo, primary impressions, study casts made, surveying and the POI chosen
WHAT IS THE DIFFERENCE BETWEEN OPEN AND CLOSED SADDLES
open is when saliva can flow through between the saddle and the abutments - closed cant (better retention but less clean)
DEFINE SUPPORT
resistance of the denture to occlusal load, prevents the denture dislocating towards soft tissues
WHICH STAGE OF DENTURE DESIGN HAS TO BE ON EACH SIDE OF THE ARCH
support (rests)
WHAT IS THE ORDER OF DENTURE DESIGN
saddles support retention indirect retention connectors review and simplify
CRADDOCKS CLASSES
1 = tooth 2 = mucosa 3 = both
WHEN CHOSING SUPPORT (RESTS) WHAT SHOULD YOU CONSIDER
abutments - size, shape, periodontal condition
root length
occlusion
aesthetics
saddle - size, position, mucosa condition
ADVANTAGES OF OCCLUSAL RESTS
can prevent over-eruption of unopposed teeth
give indirect retention
aesthetics
WHEN DOES A SADDLE REQUIRE MORE THAN 2 RESTS
when a bounded saddle as more than 3 teeth missing
DEFINE RETENTION
retention is the resistance to vertical dislodging forces and stops the denture falling out the mouth
WHICH COMPONENTS CAN GIVE RETENTION
clasps major connector minor connector adhesion - salivary suction engaging soft tissue undercuts (flange) composite to create undercuts friction - multiple saddles altered POI guide surfaces precision attahcments/implants muscle control
WHICH COMPONENTS CAN GIVE RETENTION
clasps adhesion - salivary suction engaging soft tissue undercuts (flange) composite to create undercuts friction - multiple saddles altered POI guide surfaces precision attachments/implants muscle control
HOW LONG SHOULD CLASPS BE
15mm CoCr
7mm SS
3 PARTS OF RPI CLASP SYSTEM
M rest
proximal guide plate D
I-bar clasp
HOW DOES AN RPI SYSTEM WORK
when forces are applied the prox plate and I-bar move downwards and forwards and the M rest remains in place - this is rounded to facilitate these movements
HOW DO GUIDE SURFACES PROVIDE RETENTION
when they are very close to denture,
when both abutments in a bounded saddle have paralell guide surfaces
DEFINE INDIRECT RETENTION
resistance to rotational displacement
WHICH COMPONENTS GIVE INDIRECT RETENTION
rests major connector minor connector saddle denture base
WHAT IS RECIPROCATION
a form of bracing used in dentures to prevent the active part of a clasp actin as an orthodontic appliance
WHAT IS BRACING
many components which stop denture moving laterally
FUNCTION OF MAJOR CONNECTOR
to connect all components
be rigid
TYPES OF MAJOR CONNECTOR
plate
bar/strap
horseshoe
ring - upper only
WHAT ARE THE TYPES OF BAR USED IN LOWER DENTURE MAJOR CONNECTORS
sub-lingual, lingual, dental
HOW MUCH SPACE DO YOU NEED FOR A LINUAL BAR
8mm
3mm from ging margin
4mm for bar
1mm for away from functional floor of mouth
WHY CAN A PLATE BE THINNER THAN A BAR
as its bigger it can keep rigidity whilst thinner (2mm vs 0.5mm)
MINOR CONNECTOR RULES
cross ging margin at right angles
finish above survey line
don’t use lots and create loads of windows
WHAT GOES ON RPD DESIGN LAB CARD
draw design with colour on arches
write : saddles/support/retention on…
which connector
don’t write indirect retention
WHAT ARE THE TYPES OF MOUTH PREPARATION BEFORE MASTER IMPRESSION
initial prosthetic treatment pre-prosthetic treatment periodontal treatment tooth prep by addition or removal endo /fixed pros prep ortho
WHAT IS INITIAL PROSTHETIC TREATMENTS
to existing prosthetics - treat denture stomatitis / adjust the occlusion
WHAT IS PRE PROSTHETIC SURGERY
remove teeth / frenums / residual roots / pathologys
improve contours of edentulous areas
WHAT ORTHODONTIC TREATMENTS NEEDED BEFORE MASTER IMPRESSION
adjust abutments - tilting / inclined
make irregular gaps more normal
WHAT ARE FIXED PROS TREATMENTS BEFORE MASTER IMPRESSIONS
can do crowns with specific guide planes
WHAT TOOTH PREP MAY BE DONE PRIOR TO MASTER IMPRESSIONS
rest seats - should 1mm thick in occlusal
guide planes - 2 parallel is beneficial, 3mm vertically
add composite to create undercuts/cingulums
WHY DO WE NEED CUSTOM TRAYS
for master impressions - accurate to patients mouth as made from primary impressions cast
WHERE ARE YOU LIKELY TO NEED TO USE GREENSTICK IN MASTER IMPRESSIONS
lower lingually
flanges
posterior seal of hard palate
WHAT MATERIALS CAN BE USED FOR MASTER IMPRESSIONS
alginate / PVS / polyether
WHEN TAKING LOWER IMPRESSIONS WHERE DO THE THUMBS GO
under the mandible
WHAT IS WRITTEN ON THE LAB CARD AFTER TAKING MASTER IMPRESSIONS
please pour casts in improved dental stone and then replicate them in 100% dental stone
also wax record blocks with shellac with wire strengthener in lower
WHAT ARE THE 2 NON-ELASTIC COMPOUND MATERIALS
greenstick and red ribbon wax
WHICH MATERIAL IS AN ADDITION SILICONE
poly vinyl siloxane (PVS)
WHICH MATERIAL IS AN IRREVERSIBLE HYDROCOLLOID
alginate
WHY IS ALGINATE GOOD FOR IMPRESSIONS
flexes - undercuts
WHY MUST YOU CHOSE THE MASTER IMPRESSION MATERIAL AFTER PRIMARY IMPRESSIONS
so that the correct wax spacer can be used when making the custom trays on the study casts
HOW MUCH WAX SPACER IS NEEDED FOR ALGINATE
3mm / 2 layers of wax
WHY IS A MASTER IMPRESSION TAKEN
to produce a master cast
to use custom tray
as chnages might have been made since primary cast so for accuracy
can duplicate to use at later stage
WHEN DO YOU TAKE A MASTER IMPRESSION
after denture design and all mouth prep
WHAT IS THE FIT SURFACE
surface of impression tray which captures the teeth
WHAT STEP MUST YOU TAKE BEFORE TRYING IN SOMEONES MOUTH PROS FROM THE LAB
disinfect
WHEN DO YOU DECIDE AND THEN TELL LAB ABOUT THE TOOTH SHADE/SHAPE YOU WOULD LIKE FOR A RPD
decide tooth shade/shape during master impressions and send on lab card
WHAT TO CHECK WHEN YOU RECIEVE A METAL FRAMEWORK FROM THE LAB
patient name
framework fits cast
cast isn’t damaged
articulator pin on table
WHEN DO YOU REQUEST A METAL FRAMEWORK TRIAL WITH RECORD BLOCKS
to register the occlusion
when there isn’t many teeth or the anteriors are missing
if not go straight to framework with tooth trial in wax
METAL FRAMEWORK TRY IN FAILURE CAUSES
fits cast and not patient = impression error
fits damaged cast = bad design/undercut blocking out, clasps too thick,
WHAT THINGS SHOULD YOU CHECK WHEN DOING A TOOTH TRIAL IN WAX
patient name, check framework over again, tooth shade, shape, position, occlusion, speech, aesthetics
WHY DO WE RECORD THE OCCLUSION
so there is a record of it
to help the technician set up the teeth
to identify rest seat areas
to control change if planning on changing it
to ensure a stable denture
to know position of teeth in relation to each other
to know whats normal for the patient
WHEN IS OCCLUSION RECORDED
cant hand articulate primary casts
cant hand articulate master casts
with the CoCr framework
HOW TO REGISTER THE OCCLUSION
OVD with and without record blocks should be the same
wills bite gauge / dividers(protractor)
WHAT ARE REFERENCE POINT WHEN ADJUSTING THE OCCLUSION
ala tragus line - posterior plane interpupillary line - guide for incisal plane dento-facial midline - if ant saddle lower lip curvature smile line previous dentures
WHY IS ACRYLIC PONTICS BETTER THAN PORCELAIN
harder - less brittle / silent in use / chemically bonded
porcelain only mechanically bonded
WHAT SHOULD BE ASSESSED ON FINAL DENTURE
occlusion, fit, smooth, aesthetics, correct design, pin on table
anterior flange/post periphery thin edges to blend
OVD same
denture finished above survey lines
polished only on non impression surface
INSTRUCTIONS WHEN GIVING PATIENT A DENTURE
pain is normal but if severe stop wearing until a few days before appointment clean it twice a day remove at night and keep in water the POI/R eating and speaking will be a bit hard at first increased salivary production how to cope risks of not maintaining it
HOW TO MIX PMMA
24g powder polymer to 10ml liquid monomer
PROBLEMS WITH DENTURE AFTER DELIVERY
the base - ulcerated areas/frenum’s/overextended
abutment morbidity
retention - clasps / overextended into sulcus
patient acceptance - varies
occlusion - heavy contact
vertical dimension - reduced/increased
