Before midterm: Tooth Modification/ Principles of Design II Flashcards
1
Q
Fxn of major connectors:
A
join components on both sides of arch
2
Q
TF? All components of partial are directly or indirectly attached to the major connector.
A
T
3
Q
5 types of Max major connectors:
A
palatal bar, palatal strap, Horse-shoe, A-P palatal strap, complete palate
4
Q
Horse-shoe major connector is aka:
A
U-shaped
5
Q
A-P palatal strap is aka:
A
A-P strap or O-Bar
6
Q
When to use Palatal Bar:
A
Anchor-span Class III, 1-2 teeth missing on each side
7
Q
Disadv of palatal bar:
A
little vertical support from palate, relatively bulky
8
Q
Don’t position a palatal bar more anterior than:
A
2nd premolar, may affect speech
9
Q
Why not to place palatal bar more anterior than 2nd premolar:
A
may affect speech
10
Q
Which is thinner, palatal bar or palatal strap?
A
strap
11
Q
Which Class partial are palatal strap typically used for?
A
Class II and III
12
Q
Width of palatal strap should be at least:
A
8mm
13
Q
Horse-shoe connector is indicated for:
A
prominent median palatine suture or an inoperable toris
14
Q
TF? Horseshoe connector may be flexible.
A
T. bc it is curved
15
Q
Contraindications of horse shoe connector:
A
Class I or II arches
16
Q
Disadv of horseshoe connector:
A
little cross-arch stabilization
17
Q
Adv of horseshoe connnetor:
A
may be flexible, rigid framework helps to distribute forces
18
Q
This type of connector is preferred over Horseshoe connector:
A
rigid major connector
19
Q
A-P palatal strap indications:
A
large edentulous span, prominent median palatine suture, inoperable torus
20
Q
Width of each A-P palatal strap should be at least:
A
8mm
21
Q
Open area on palatal region of A-P palatal strap should be at least:
A
15 X 20mm
22
Q
Connectors to use for pts with inoperable torus or prominent median palatine suture:
A
horseshoe, A-P palatal strap
23
Q
Posterior segment of the A-P palatal strap adds:
A
rigidity
24
Q
Benefit of keeping open palatal portion bw straps of A-P palatal strap connector:
A
tongue / palate contact, taste, temperature
25
Connector that provides that greatest rigidity and support:
complete palate
26
Indications, complete palate
all posterior teeth replaced, perio compromised teeth, provides additional vertical support
27
Disadv of compete palate connector:
tissue health may be compromised POH
28
TF? Complete palate connector provides additional horizontal support.
F. Vertical
29
6 types of Man major connectors:
Lingual bar, lingual plate, sublingual bar, double lingual bar, cingulum bar, labial bar 5 bars and a plate)
30
double Lingual bar is aka:
continuous bar
31
Most freq used man major connector:
lingual bar
32
Adv of lingual bar for man major connector:
minimizes contact w teeth/ soft tissue
33
Contraindications of lingual bar:
lingual tori (usually)
34
Where to place bar for pt w lingual tori:
past contacting lingual aspect
35
Lingual bar requires at least __mm of space bw gingival margins and floor of mouth.
8mm
36
Lingual bar should be located here:
in the most apical position the movable soft tissues will allow
37
Type of man major connector to use if you don't have room for the 8mm bw gingival margins and floor of mouth:
lingual plate
38
Shape of lingual bar in X-section:
half-pear
39
Adv of lingual bar:
wider, stronger at bottom
40
Indications for lingual plate
1': less than 8mm for lingual bar, 2': reduced perio support
41
Why is a lingual plate man major connector good if the remaining teeth have reduced perio support?
Force distribution over teeth and soft tissue
42
This man major connector scallops around anteriors:
Lingual plate
43
When to use lingual plate:
when not enough room for lingual bar
44
Disadv of Lingual plate:
covers a lot of tooth surface, minimizes cleansing action
45
TF? Teeth can easily be added to lingual plate.
T
46
TF? Lingual plate can often be used to avoid covering lingual tori.
T
47
Where should the inferior border of the lingual plate be positioned?
as low in the floor of the mouth as possible wo interfering w functional movements of tongue and soft tissues
48
TF? The major connector of the lingual plate should extend as far as movement allows.
T
49
From where to where is the superior border of the lingual plate scalloped?
from cingulum to interproximal contact
50
Lingual plate should eb supported by:
rests on mesial fossae of 1st premolars
51
What give vertical suppport for the lingual plate?
Rests on either end of plate
52
Disadv of lingual plate:
extensive coverage, decalcification, irritation of soft tisuse w POH
53
Scalloping of lingual plate is aka:
"step backs"
54
What are step backs of the lingual plate used for?
to accommodate diastemas (prevents display of metal)
55
TF? Lingual plate extends up to the cingulum and around the M and D surfaces of each tooth, but not into the interproximal area.
F. does not extend to M or D aspects of each tooth
56
Man major connector to use to maintain diastema.
lingual plate
57
Major connector is on the labial side of teeth for this type:
labial bar
58
Double lingual bar is aka:
continuous bar
59
What is the double lingual bar?
both sublingual bar and cingulum bar
60
When to use cingulum bar vs. lingual bar:
shallow floor of mouth (FOM)
61
Req's of Major connector:
rigid, protects soft tissue, provides means for direct retention where indicated, and placement of a denture base, comfortable
62
Max major connector borders should be:
at least 6mm from free from, and parallel to, gingival margins
63
Man major connector borders should be:
at least 4mm from the free from, and parallel to, gingival margins.
64
Mandibular major connectors should be below:
sulcular depth, not occlusion blood supply
65
TF? Anterior border of man major connectors should end on anterior slope of rugae
F.
66
Anterior border of man major connector should end here:
posterior border of rugae
67
Man major connectors should be:
as symmetrical as possible, cross palatal midline at R angles
68
What happens when the length of the major connector is reduced?
red irritation potential (?)
69
Man major connector to avoid tori:
lingual plate w lingual connector
70
TF? Small torus can be covered.
T, but provide relief
71
Harder to avoid, man or max torus.
Man
72
TF? Mandibular tori usually require removal for partial fabrication.
T
73
Sharp corners on a partial can lead to:
Discomfort, stress concentration, susceptible to fracture
74
Fxn of minor connectors:
join partial to major connector
75
parts joined to major connector via minor connectors:
clasp assemblies, indirect retainers or auxiliary rests, denture bases, approach arms for infrabulge clasps
76
TF? Denture base joined via latice-work is consider a minor connector
T
77
minor connectors should have sufficient bulk of metal wo:
encroaching on tongue
78
Minor connectors are positioned in:
lingual embrasures
79
What to avoid when designing minor connectors:
narrow windows
80
Windows of minor connectors should be at least _mm wide.
5mm
81
how are rest seat connected?`
via minor connect + proximal plate`
82
Examples of minor connectors:
indirect retainer, proximal plate, latticework
83
Fxn of indirect retainers:
resist forces acting to dislodge prosthesis from seated
84
Forces attempting to dislodge prosthesis come from:
sticky foods, gravity, etc.
85
TF? Indirect retainer is considered a minor connector.
This is the framework component that resists rotational displacement of an extension base away from the supporting tissues
86
Forces exerted down the long axis of a tooth via the clasp lead to forces being exerted here:
up on the distal portion of distal extension
87
When does partial denture exhibit indirect retention?
When rotational forces are counteracted by placing indirect retainers
88
Which type of partials require indirect retention?
All Kennedy Class I, II, and IV (III doesn't)
89
TF? The proximal plate is broad M-D and thin B-L
F. vice versa
90
Benefit of proximal plate being broad BL and thin MD:
easier to put denture tooth in natural position
91
M-D dimension should of proximal plate should be:
as narrow as possible, to preserve denture tooth space (about 1mm+)
92
GP criteria:
2/3 width of BL cusps, MR to junction of middle and gingival 3rd
93
GP criteria for GP adjacent to distal extension:
2/3 width of B-L cusps, Mr to middle 1/3
94
Benefit of GP adjacent to distal extenion being shorted I-G than all others:
Allows framework rotation
95
Types of lattice ork;
mesh, open loop
96
Lattice work to use w limited space:
mesh
97
Fxn of lattice work:
hold acrylic
98
How far to extend distal extension lattice work
2/3 of alveolar ridge, past most prominent area of tuberosity
99
TF? Extend lattice work to hamular notch.
F. to most prominent area of tuberosity
100
This is where the acrylic joins the framework:
finish lines: external and internal
101
What's the difference bw the internal and external finish lines?
check?
102
Desired angulation of internal finish line:
<90’ for flush junction and mech retention
103
Function of internal finish line angulation less than 90':
provide flush junction and provide mechanical retention
104
Open loop lattice work is only needed for:
distal extension
105
Fxns of tissue stops:
vertical stop on cast, flexing of framework during acrylic processing, stability to framework while setting teeth
106
TF? All cross bars of distal extension provide vertical stops.
F. not the most posterior portion
107
Tissue stops are only relevant:
during acrylic processing and evaluating on cast, not to support framework in mouth!!
108
What does it mean if the tissue stop is not contacting after processing of the cast?
Error during fabrication. in contact w cast
109
Only time to adjust the most distal portion of lattice work:
Pain and a pressure spot
110
When are abutment teeth prepared?
prior to tooth modifications
111
Before tx plan can be modified, you must:
mount dx cast, survey and design RPD
112
Steps that must be done bf tooth modifications:`
relief of pain/ infection, complete surgical proc, correction of occ plane/ malalignment
113
When to extract teeth for partials:
non-restorable, inadequate perio support unerupted/impacted
114
Do we have all unerupted 3rd molars extracted before any partial fabrication?
check. If so, why?
115
Surgeries that should be done before partial design:
extractions, tori / exostoses removal, reduction of enlarged tuberosities (no room for denture)
116
Issue for ppl w large tuberosities:
no space for dentures
117
How to manage minor supraeruption of teeth:
recontour occ surface (enamoplasty)
118
How to manage moderate supraeruption of teeth:
onlay or crown
119
How to manage severe supraeruption of teeth:
extraction
120
When to expose dentin when recontouring tooth to correct occlusal plane:
never
121
When is ortho indicated bf partial design:
distal molar tilted mesially, most pts won't spend the $
122
Define enamelplasty:
recontouring of axial surface
123
TF? Enamelplasty requires local anesthetic.
F
124
Enamelplasty:
conservative, in enamel, polished, practice on cast if substantial recontouring needed bc you want to know if pt is becoming sensitive to adjustment
125
Why not to give pt LA for enamelplasty:
you want to know if the pt is becoming sensitive to the adjustments
126
one way to correct clinical orientation of crown to avoid over contouring (excessive or insufficient undercut):
Survey crown, optimally contoured
127
Survey sequence:
rest seat, GP, retention, reciprocation
128
Sequence of tooth mods:
GP, HOC, rest preps
129
GP of tooth mods for partial must allow:
direct seating and stabilize against lateral forces
130
GP criteria for tooth mods for partial insertion:
2/3 width of B-L cusps, MR to junction of middle and gingival 3rd
131
GP for tooth supported partial require GP with these dimensions:
2/3 width of B-L cusps, MR to junction of middle and gingival 3rd, maintain B-L contour
132
GP for distal extension (tissue supported partial, Class I or II:
MR to middle 3rd, permits rotation of framework
133
Benefit of additional rotation of distal extension:
minimizes torsion on abutment tooth (smaller GP)
134
Any partial that is supported by ___ will rotate.
tissue
135
TF. The bur should always be aligned with the long axis of tooth when making tooth mods.
F. with POI
136
Survey crown is indicated when:
modification would expose dentin and compromise contour bc crown is tilted too much
137
When to reduce on the cervical aspect of a tooth:
never, thin enamel
138
Desired edge when making GPs:
Featheredge
139
Location of retentive clasp:
gingival 3rd, 1.5-2mm from gingival margin
140
Location of middle/ shoulder region of retentive clasp:
above HOC
141
Reciprocal arm location:
junction of middle and gingival 3rd, always at or above HOC
142
Place ___ clasp as low as possible and __ clasp as high as possible.
retentive, reciprocal
143
Lateral force on tooth start when:
the retentive and reciprocal clasps touch the tooth for the first time and at same time
144
Ideal location of HOC undercut in relation to margin:
1.5-2mm from margin
145
When developing a retentive UC, this is the desired contour change:
Gradual, subtle contour change, not a semicircle 1.5-2mm away from gingival margin
146
Other indication for recontouring:
adjust excessively convex proximal surfaces for improved esthetics, mesially drifting tooth encroaching on edentulous area to idealize spacing, lingually tipped teeth, for better adaptation of minor connectors
147
When to recontour mesially tilted teeth:
to allow better adaptation of minor connectors or proper seating of major connector
148
When should aspects of framework crossing over undercut regions of tooth engage the UC region?
never
149
Minor connection in relation to tooth:
must be well off tooth, better to recontour tooth so framework components can be fabricated closer to tooth and not be annoying to pt
150
Pour cast in this stone to quickly check tooth mods against surveyor:
snap stone
151
When to do rest preps:
after verifying GP's and HOC
152
How to get snap stone cast back in same orientation as the original cast:
no way to, reestablish based on new snap stone
153
Bur shape to use when making rest preps:
bullet shaped
154
Additional space must be allotted for this when prepping survey crown:
rest seat
155
Materials that can be used for survey crowns:
CCC, MCC
156
TF? Tooth mods on other abutment teeth should be done bf final impression for survey crown:
T
157
When doing SC, at what point do you do tooth modification?
Prior to survey crown bc it is more ideal to have already done tooth mods on all other teeth, then fabricate survey crown to develop ideal contours in relation to abutments and to utilize the contours of the other teeth (lab tech)
158
Which is better, to make tooth mods before or after survey crown is inserted?
before
159
Have these completed bf clinic for RPD pt:
mounted dx cast, surveyed, with drawn design (some faculty want mods done on duplicate cast), approved tx plan in Picasso, Chart design form, completed and signed
160
Instruments to bring to a RPD appt:
surveyor, proper burs and polishers, snap stone, stock impression trays, alginate
161
Common mistakes:
presenting tx plan to pt wo considering RPD design, make tooth mods prior to impression for survey crown, explain to pt the need for tooth mods
162
Pts most likely to object to tooth mods;
those w prior RPDs
163
How might the RPD design influence the overall tx plan?
need for survey crowns may not be obvious until surveying cast
164
TF? Finalization of tx plan can be done before surveying dx cast.
F.
165
Faculty to sign up w when working w RPD pts:
removable faculty
166
Which faculty can approve RPD final design?
only removable faculty
