Overview of Partials (ORACGUBT) Flashcards
Order of Making a partial
- occlusal analysis
- rotation analysis
- Abutment selection
- clasp selcetion
- guide plane survey
- undercut analysis
- bracing survey
- tripodization
breakdown of occlusal analysis (4)
- plane correction
- extrusion potential
- overbite problem
- spaces selected for PD
*this is the order you evaualte the occlusal plane
breakdown of rotation analysis
- spaces to be restored by the partial?
- size of those spaces?
- support of those spaces?
rotation causes?
torque
torque causes?
tooth loss
what is kennedy classification DETERMINED by?
Occlusal analysis
tipped teeth are more likely to..
torque
lone standing teeth are more likely to …
torque
indirect retention reduces what?
torque
3rd sequence in denture making for partials
abutment selection
breakdown of abutment selection ***
- as many GUIDE PLANES as possible
- as FAR APART as possible
- symmetry WHERE possible
- no INCISORS (
- no lone-standing premolars as primary abutments (ever– due to tipping and root length and shape)
- no lone standing canines or molars if possible (a tooth with a neighbor results in less tipping)
- Extrusion prevention (rest placement on unopposed teeth)
- indirect retention
- esthetics
4th sequence in abutment selection
clasp selection
breakdown of clasp selection
- type 1 vs type 2 clasps
- rotating vs non-rotating partials
- class 1 vs class II levers
examples of type 1 clasps
cast C clasp - non rotating
combo - rotating
examples of type II clasps
RPI clasp(smallest of type II and most perferred)
Bar (DB u/c ) rotating
what can you do for tissue undercuts and bulky teeth? implication on guide planes?
tail down tilt – may draw the tissue closer to analyzing rod and reduce the distance between the approach arm and the tissue
- but the guide planes need to be modified as they become guide points!!!
5 incorrect uses for approach arms – if you do what does it cause?
- double arms
- skipping of teeth
- lingual or palatal
- reverse or distal
- molars
- buccal shelf
- zygomatic arch
will cause TORQUE
where do RPIS go
cuspids and premolars
levers cause…
torque
second clasp levers have the ability to
reduce torque because they push down
the rest ____ to the rotation = the lever
CLOSEST
first three design priorities
- protect TEETH if bone strong
- protect BONE if teeth strong
- if (abutment) teeth weak, treat as Distal Extension w/ RPI
- If bone weak, treat as Distal Extension w/ combo
to protect teeth during rotation what do first three things you use
- use the SMALLEST CLASP possible
- use the MOST FLEXIBLE metal possible
- use the BEST LEVER possible
5th sequence in building a partial
Guide plane survey
what steps are “our hypothesis” and which ones are our “testing hypothesis”
first 4 - our hypothesis
last 4 - testing our hypothesis
breakdown of guide plane survey
- proximal surfaces
- occlusal 1/3
- disl parallel to path
6th sequence in partial planning
Undercut Survey
breakdown of undercut survey (5)
- facial or lingual surfaces (+/- tissue)
- gingival 1/3rd
- dimple flat surface –> 0.01 (0.02–> 0.03)
- disk non-parallel to lower type I clasp
- disk parallel to lower type II clasp
how do you lower a type I clasp
disk non-parallel
how do you disk to lower a type II clasp
Parallel
7th step in making partial
Bracing Survey
breakdown of bracing survey (3)
- arm, blanket or 2 minor connectors
- gingival 1/3
- disk non-parallel to lower height of contour
options for major connectors (6)
4 upper
2 lower
lower
1.
2.
what are we using to diagnose plane correction?
- same arch
- opposing arch
- retromolar pad
- radiograph
*do you have enough space in these areas to put a partial denture
plane correction methods
- enamoplastty
- restoration
- endodontics
- Extractions
analysis of the occlusal plane requires what?
MOUNTED casts
when determining the occlusal plane what are we looking at?
Lip length
Fricatives
what do you do for teeth that have extrusion potential
if not good primary abutments must make them secondary abutments and lace rests on them to prevent extrusion, drifting, or rotation
also if class II mod 1 with distal molar and dont put a rest on it then it becomes a bilateral distal extension (class 1)
what do you create if you do not put a rest on lone molars in the back
a distal extension lever
anterior overbite may result in what if dont compensate for it? what can you do as a solution?
Incisal guidance
**use a STEELE’S FACING
rules of complete denture occlusion
- CR=CO
- no incisal guidance in protrusion
- no canine guidance in lateral
- no anterior contact in CO
rules of partial denture occlusion
SAME AS COMPLETE
- *UNLESS
- BOTH upper and lower opposing teeth are NATURAL
what do you do in anterior to make sure we follow denture rules? in the posterior?
ANTERIOR
- increase horizontal overlap
- decrease vertical overlap
POSTERIOR
- increase cusp height
- increase compensating curve
if patient has complete upper or complete lower what rules?
COMPLETE rules
- both opposing arches that contact have to be natural teeth
when will a class III or class IV be more likely to rotate
if the patient is also missing their canines –> good chance the anterior space will rotate too
*trickiest ones are the ones that have spaces missing MESIAL to the axis of rotation
where do you place the rests in a mesial extension
on the DISTAL
mesial rotation clasp?
combo most likely
rule for abutments and incisors?
NO incisors because of phonetics and tipping due to tilt, root length, and shape
*only exception is cingulum rests if have to use lingual blanket on the bottom
if clasping pre-molar on one side and opposite side is lone standing what do you do and why?
put a rest on it
*for symmetry purposes
lone standing MOLAR rules for non -rotating partial with long span
OKAY as primary abutment and use a RING CLASP
what do you do with lone standing molar with no proximal surface?
treat as a distal extension case
lone standing MOLAR rules that have a potential to rotate w/ long span
treat as a rotating PD (distal extension)
- place rest on mesial
lone standing molar that is short, mobile, or tipped?
treat as a partial that has a potential to rotate and put rest on it
long span with tipped molar but non-rotating– what do you do with molar
can put a RING CLASP – increased bracing
most esthetic clasp?
RPI
what is in the undercut in type II clasp
only the retentive tip
is the approach arm in type II clas retentive?
no – only the retentive tip
if tissue bulge can we do an RPI/ have an approach arm
yes – as long as there is 3mm - the arm can contour the tissue
just cannot have undercut tissue
approach arm used with tooth with tilt?
if extremely tilt we cannot use it – too far away from the tissue
compensate for tissue undercuts or bulky teeth?
tail down tilt – may draw the tissue closer to the analyzing rod and reduce the distance between the approach arm and the tissue
approach arm contraindication with maxillary and mandibular molars?
buccal shelf interference
Maxillary – zygomatic arch
do we need to engage undercut when pt. bites?
NO.
only when patient LIFTS
what is more important to achieve; clasp or lever of choice
ALWAYS GET LEVER OF CHOICE and then pick best viable clasp
RPI vs RPA (wire) when bite down in terms of contact
RPI
- breaks contact but uses ridge as fulcrum
RPA -wire
- Remains in contact but wire absorbs stress)
what is the fulcrum in RPI when biting down
RIDGE
if ridge is poor in rotating partial, what is clasp of choice?
RPA combo because RPI uses the ridge as a fulcrum when biting
design priorities #1-4
- protect teeth if bone is strong
- protect bone is teeth strong
- if abutment teeth weak, treat as DE w/ RPI
- If bone weak (ridge) treat as DE w/ COMBO
if abutment teeth are weak? what do you do with design?
Treat as a distal extension with an RPI clasp (combo on molar)
three things to do to protect teeth during rotation
- use the smallest clasp(least metal) possible
- use the most flexible metal possible
- use the best lever possible
if approach arm contra-indicated in rotating partial what do you use?
combo -RPA
clasp of choice in a non-rotating partial?
C-clasp
then second choice is any
guide plane is located? width and lenght?
anywhere from line angle to line angle and 2mm wide and 2-3 mm long (@ a minimum)
how to make a guide point to a guide plane
disk enamel parallel to the path of insertion
ideal undercut location
2mm above the free gingival margin
why should we be so concerned with the lingual tissue survey?
excessive lingual tilt of a tooth may interfere with the major connector
what type of tooth can we not dimple
those that converge from FGM to the occlusal surface (have to do flat surface) or an undercut to make more of an undercut
if the analyzing rod hits the HOC at the FGM why is this a problem? solution?
you cannot place a dimple/undercut here and have to look at the lingual for a possible undercut (but only for type I clasps)
- type II clasps dont have retention on the lingual
clasps cause..
torque
what can lowering of clasps reduce?
torque
what will placing clasps as gingivally as possible do?
reduce rotational or tipping forces
origin of the clasp arm
from the mid-gingival 1/3 of the minor connector
result of disking non-parallel to path in type 1 clasp
lowers height of contour
result of disking parallel to path in type II clasp
raises height of contous and brings approach arm closer
bracing in rotating partial?
2 minor connectors
or lingual arm for molars
use of a bracing arm?
buccal or lingual depending on retainer
use of a blanket?
bracing on lingual ONLY ON CUSPIDS
use of minor connectors?
for bracing lingual ONLY for type 2 clasps on cuspids or pre-molars in rotating partials
lowering the bracer reduces what?
torque
if bracing arm is type I what do you do to lower height of contour / survey line
disk non-parallel to path
Three facts about tripodization
- on 3-sides of cast
- records A/P and lateral tilts
- so it records the path – which determines guide planes, ht. of contour and survey lines - mist be included in CROWNED abutments
superman’s cap refers to?
refers to the identification of an axis of rotation of a partial denture and the need to protect any abutment associated with this rotating partial
need a low what wherever you are bracing
LOW height of contour on lingual or buccal
which teeth likely need to be disked to lower height of contour? why? how?
the linguals of posterior mandibular teeth and you disk them NON-PARALLEL so we can move bracing ARM to the gingival 1/3 so that you directly oppose the retention on the other side
ideal dimensions of clasps
- as FEW as possible
- as LOW as possible
- as SMALL as possible
what do you do to help stabalize if have to use a horshoe
add more guideplanes to distribute the horizontal forces better because this partial design rotates horizontally
indications to use a horshoe
inoperable tori at the location of the junction of the soft and hard palate
