Framework Flashcards
4 types of tissue blockout
- parallel blockout
- arbitrary blockout
- ledges
- 22 and 30 gauge relief
who is responsible for the design of the partial denture
YOU - the dentist
purpose of parallel block-out relief wax
protects the path
purpose of the arbitrary block-out relief wax
protects the TISSUE
purpose of the ledges block-out relief wax
for clasp location
purpose of the 22 and 30 gauge block-out relief wax
for ACRYLIC – (under mesh-work), approach arms and lingual major connectors
ledges are placed where for C clasp?
DIRECTLY UNDER the drawings - because when duplicated to refractory cast we do NOT have the drawings anymore so ledges will guide us to where they need to be
ledges are placed where for RPI clasp?
placed along SIDE of the drawing
tissue stop does what two major things
- only part of the distal extension meshwork that contacts the tissue
- the only part of the denture that predicts how accurately the acrylic will contact the tissue
position of the tissue stop?
always forward of the RMP
what do you use to make tissue stops
created with the 30 gauge wax
refractory cast?
DUPLICATE of the final cast
*final cast is duplicated in investment –> refractory cast
where is the wax up done on?
refractory cast
after wax up is done, next step?
the wax up is sprued, invested and cast
what is done and what is the order of these tasks prior to duplicating the final cast?
- DRAW design and frame-work on the final cast
- Parallel and arbitrary block-out is completed
(parallel = guide planes so PROTECTS PATH)
(Arbitrary = protects TISSUE) - ledges for clasps are waxed in
- relief for acrylic and metal is done
what is needed to make a tissue stop
a whole in the relief wax
what happens to whole in relief wax for tissue stop?
after casting –> converts this space into a POSITIVE metal stop in the framework
how you know partial is sitting well on mandible and maxilla?
Maxilla - Major connector *** because it also seats on the tissue + the TISSUE STOP
Mandible
- ONLY TISSUE STOP
- because major connector is not touching tissue like it does on the palate of the maxilla
where do you place maxillary tissue stops?
also placed in distal extension areas
- can decrease canteliver effects
altered cast impression technique cannot be used where?
NOT POSSIBLE on MAXILLARY frameworks
material used for final cast
poured with STONE
material used for refractory cast
poured in CASTING investment
describe the creation of the refractory cast
comprised of INVESTMENT
it is a DUPLICATE of the final cast with RELIEF WAX ADDED
sprue pin?
creates a pathway for the molten alloy to go into
minor connectors need which wax?
parallel blockout
arbitrary block-out placed where?
near the free gingival margin
protecting the tissue - so where we think metal may come into contact and want to protect the tissue
like on the palate if we have some irregular rugae
ledges guide us for what?
where we will place the clasp
set up of approach arm where do you place 30 gauge and where do you place 22 gauge?
30 –> right before undercut of approach arm
(creates SPACE between approach arm and tissue)
22–> right distal to the approach arm contacts meshwork
tissue stop uses what relief wax? purpose?
30 gauge – room for acrylic
acrylicc- mesh-work–acrylic
if tissue stop is off what else is off?
OCCLUSION
where is hole placed when making tissue stop?
hole is placed in the relief wax on the RIDGE so the position of the tissue stop is just forward of the rise of the retro-molar pad
parallel blockout position in relation to the guide plane?
ends JUST BELOW the guide plane
need tissue stops on both maxilla and mandible?
MAXILLA
- optional here because of the major connector contacting the palate – depends on the size and rigidty of the maxillary major connector (probably in large distal extensions they are necessary)
MANDIBLE
- REQUIRED – because the mandibular major connector is relieved from mandibular tissue
importance in the junction between waxes
must remain SHARP to maintain the FINISH LINE
relief wax gives rise to what?
internal finish line
where do you see tooth to fold and where do you see tooth to notch?
tooth to fold = lingual
tooth to notch = maxillary
butt joint?
90 degrees and is a junction of metal and acrylic where major connector meets denture base preventing leakage at their interface
where is frameowrk high finished and polished?
mandibular major connector (tissueside)
approach arms (tissue side)
Tongue side of anything
where is frameowrk medium finished and polished?
clasps - tooth side
rests – tooth side
where is frameowrk low finished and polished?
meshwork
max major connector (tissue side)
framework accuracy =??
fit of RESTS and rest seats
definitive determinate of if partial is fitting
if rests seats sit
first five things you check for fitting of frameowrk on cast
- RESTS
- Abrasion
- fractures
- relief
- tissue stops
internal bead check? location implication
care should be taken to avoid placing a bead in a non-compressible tissue such as the median palatal raphe or the anterior rugae areas
- this will prevent rebound of the framework against non-compressible tissues during try-in
purpose and dimension of the internal bead
metal margin or bead is .5mm deep
provides intimate tissue contact preventing food from easily dislodging the prosthesis
external finish line dimesnsion
90 degrees to crest of ridge and depth of 1mm
butt joint between acrylic and meshwork
tooth to fold internal finish line dimensions and location
perpendicular to the crest of ridge (NOT at an oblique angle) it is 1mm deep and at a butt joint
all meshwork ends at?
ridge crest
meshwork is required where?
only where teeth will be
tooth to notch finish line ends and extends?
extends into hamular notch but meshwork and teeth end at tuberosity
tooth to fold meshwork ends?
before retromolar pad
T/F tooth to notch finish line extends into hamular notch
TRUE
- but meshwork and teeth end at the tuberosity
all meshwork ends where?
at ridge crest
T/F guide plane should be contacting tooth
YES - with slight space below
how to evaluate/ what to look at with clasps
- position of arms
- taper of tips
- degree of undercuts
where is a good location for the clasp to originate from in combo / or C?
middle 1/3 of the tooth from the minor connector
- dont want it in the occlusal 1/3 as the survey line was likely too high
partial denture clasp adjuster
used to make minor adjustments to framework CLASPS
enables one to slightly tweak or bend the clasp tip TOWARD tooth only
C-C is brittle (fragile) and can break so do not bend multiple times
wire arms can be adjusted multiple times in multiple directions
are you tightening or loosening with the clasp adjuster
tightening
direction you bend with clasp adjuster
tweak or slightly bend the clasp tip TOWARD THE TOOTH ONLY
if see that the clasp tip is not touching the tooth what is next step?
do NOT tighten it until pt. tries it in…could hit the patient’s tooth and so make sure it needs to be tightened before you do it
so must see this CLINICALLY
if cast clasp CLINICALLY touches tooth too tightly what is next step?
disk/ rubber wheel the inner aspect of clasp tip and do not bend
if one clasp is too tight and one too loose what is next step?
disk inside / rubber wheel the tighter one before tightening the other loose clasp
where can you NOT bend the arm of any cast clasp
from the base/ origin of the clasp
T/F you can bend wrought wire toward or away from the tooth
TRUE
is abrasion seen on cast a problem? where?
YES - depends where though
problem at guide plane – may indicate that it is excessively binding in these area and need to be careful when place into patients mouth
NOT a problaem if on facial surface or CLASP TIP (like the 1/3 closest to tip) where clasp is engaging and actively crossing bulge
important to have a clas arm taper?
YES (if not it is possible for clinician to make this correction)
usual cause of a non-tapered clasp tip
small wax which was placed to secure wax pattern during casting
importance of checking framework on cast against opposing cast
to ensure ALL RESTS are NOT overly thick or no bulky solder or weld joints which can interfere with occlusion and increase VDO
if survey correct but excessive block out was done? result? what type of error?
then the arm will be too far from the tissue and NEED TO RECAST
lab error
if survey correct but insufficient block out was done? result? what type of error?
then clasp arm will be too close to tissue and need to recast or grind if possible
lab error
if survery incorrect (HOC too high/ bulky what is result? what type of error?
need to redesign/ re-survey
Clinician error
use of wide minor connector
if pre-molar has drifted and we want to re-establish proximal contact
- so can use pre-molar as primary abutment AS LONG AS SPACE TO BE CLOSED IS NOT MORE THAN 1-2MM
if framework does not seat clinically what are potential reasons
binding on a vertical metal component
- guide plane or
- minor connector contacting an abutment
excessive bead on maxillary major connector causing rebound
use of fit checker
used to adjust guide planes and minor connectors and placed where ever metal may be binding
- where you think it is not seating
before you make any adjustments on partial what should you do?
check with iwanson gauge and then grind accordingly using heatless stones and finishing carbides
*so always checking the thickness
after framework fits what do we check next?
check the tissue stops
what does the altered cast impression enable for?
re-establish relationship of soft tissue of MANDIBULAR distal extensions to framework
*using the tissue stop as the reference
ask if the relationship to the soft tissue really still there
space underneath the tissue stop (sits above ridge) likely result of? what do you do?
means we probably over compressed the tissue
place compound underneath until get contact and then have to make it permanent
if tissue stop is impinging on the ridge? what do you do first?
blanching the tissue now
now have to grind the tissue stop until we dont see the blanching anymore
first grind it with a diamond bur
if tissue stop not fitting?
make trey on meshwork and border mold
- making new final impression
describe Final impression of distal extension
getting a new final mucostatic soft tissue impression
cut away the old part of the cast – so removing the distal extensions from the original cast because the new altered cast impression will not fit back on original cast
why do you remove the original cast distal extensions
cut away with dovetails to increase mechanical retention with beading and boxing
enhances the mechanical retention and altered cast impression will not fit back on original cast
altered cast impression can only be done on which arch?
MANDIBLE
- can be done unilaterally or bi-laterally
- only done on distal extensions
outcome of an altered cast impression technique is most predictable when?
when there are multiple rest seats present for stability
T/F guide plane can be a little off the tissue and stop on the tissue
true - because want the guide plane to slide down when patient bites down
describe the sequence of problems if tissue stop above the tissue
tissue stop above –> acrylic above –> CANTILEVER –> trauma/ tooth loss
describe the sequence of problems if tissue stop in the tissue
tissue stop blanching –> denture base REBOUND –> HYPER-OCCLUSION –> bone loss
if cast fits framework but not patient likely cause? what should you compare?
probably a poor impression
compare the final cast with diagnostic cast for more clarity
tissue stops must always be visible when?
during try in
after processing
wax rims added to?
framework
maxilla height of wax rims
anterior to tuberosity and height depends
- level off to teeth if present
- parallel to posterior ridge then make adjustments accordingly
mandible height of wax rims
1/2 to 2/3 height of retromolar pad and anterior to the retro-pad
- based upon the use of flat or curved occlusal plane
how do we determine VDO if no posterior contact exists in PD?
same way you do for complete dentures
VDR-VDO= freeway space (inter-occlusal rest distance)
sibilants and fricatives
retromolar pad
closest speaking space
esthetics
freeway space deterimined by / definition
-VDR-VDO= freeway space (inter-occlusal rest distance)
use of CR vs MIP in making partial dentures?
no posterior contact –> we use CR
stable MIP? –> we use this because it is REPRODUCIBLE
only using MIP if there is a reproducible posterior occlusion
MIP is…
a REPEATABLE position DEPENDENT on TOOTH CONTACT
recording method if no posterior occlusion
uses bases and rims with notch vs. aluwax
recording method if posterior teeth present but no posterior occlusion
use bases and rims with TEETH vs. aluwax
recording method if posterior occlusion is good
use baseplate wax or hand articulate
shorthand
shorthand reflects teeth present/absent, not what rules of occlusion are being applied
rules if natural anterior teeth and denture posterior teeth
Pt. can have incisal guidance and canine guidance and anterior contact in centric
however … posterior must use/ have to mount the case in CR
rules if natural anterior on lower only and denture posterior teeth
anterior
- no anterior contact in centric
- no incisal guidance
- no canine guidance
posterior
- use CR
rules if natural anterior teeth on lower only and natural posterior teeth in occlusion
you have to use denture rules in the anterior but may mount the case in MIP in the posterior
**if not stable enough to hand articulate you have to use record bases and occlusion rims
what do you use if case not stable enough to hand articulate
need to use record bases and occlusion rims (even if you can mount in MIP)
treatment of choice for single tooth spaces
- fixed/implant
- facing
- tube
using facing if
severe overbite
severe tissue undercut
minimum resorption / flange not desired
minimum surface area
using tube tooth if
small space and large tooth
other applications for steele’s facing
where bone has no resorbed
flange is not wanted
insufficient occlusal clearance
*can use multiple facings for severe overlap and bone sufficient
guidelines for choosing tooth size
MATCH remaining teeth if possible or select LARGER teeth if the match not possible
guidelines for choosing tooth shape anterior and posterior
anterior
- match shape of remaining teeth or shape of FACE
posterior
- match opposing cusp height
- match shape of remaining teeth or amount of remaining ridge
acrylic may oppose what type of denture tooth material
can oppose acrylic
can oppose enamel
CANNOT oppose porcelain
rules with porcelain as denture tooth material
must NEVER OPPOSE ENAMEL
**porcelain anteriors must NEVER be used with acrylic posteriors
***acrylic anteriors may be used with porcelain posteriors if ridge is not resorbed
only combination of porcelain and acrylic denture tooth material that is acceptable
if ridge is NOT RESORBED … then acrylic anteriors may be used with porcelain posteriors
porcelain crown vs porcelaine denture teeth when opposite enamel
CROWN
- will have a final glaze following occlusal adjustments which PROTECT ENAMEL
DENTURE TEETH
- cannot be re-glazed following occlusal adjustments and will ABRADE THE ENAMEL
major difference of processing in complete and partial dentures
entire framework gets embedded into the flask along with the final cast
*in complete there is no frame in the lower 1/2 with the final cast
insertion sequence (5)
- adjust acrylic
- adjust occlusion
- teach patient ‘path’
- give homecare instructions
- reappoint for adjustment (Toothe borne vs distal extension–> will need more time )
insertion problems regarding metal corrected when?
at frame and tooth try in appointment (4th appointment)
insertion problems regarding acrylic corrected when? where?
WHERE
- in guide plane undercuts
- around clasps causing decrease in flexibility
- in tissue undercuts
sequence of adjustments in tissue undercuts
- posterior first
- posterior - evenly
- then anterior last
what do you use to check tissue undercuts and acrylic against tissue surfaces
PIP and sorens paste which is brushed on the intaglio surface
- acrlyic around the clasps, in tissue undercuts, and in the guide plane undercuts then the denture borders
when using PIP and seating the denture …rests not in seat.. why?
problem is in the acrlyic do not grind the metal
if one side of partial seats first what does this mean for removal?
seats first – then it comes out last
path of insertion implication on placing in patients mouth
if had to make adjustments on cast keep this in mind when inserting it in patient
- fingers underneath the clasps when removing
homecare maintenance
brush for cleaning
NO TABLETS WITH CHLORINE BLEACH – IT WILL OXIDIZE THE FRAMEWORK
if patient has symptoms of pain, sensitivity, and occlusion problem what is the likely reason?
tooth changes
- hyperocclusion
- malocclusion
- clasp design or position
- bracing is less than 180
if patient has symptoms of occlusion, borders, internal surfaces, white sores (more new), and red sores (more older) what is the likely reason?
tissue changes
- hyperocclusion
- malocclusion
- resorption
- reline, rebase?
during recall appt. for pt. with DE RPD what must you evaluate?
ridge resorption, rocking/fulcruming, and a potential need for reline/rebase
