Lec 1/12 Partial FDP MCC & ACC I Flashcards
1
Q
Indications for leucite based fixed prosthesis:
A
anterior crowns, veneers, inlays and onlays
2
Q
Indications for lithium silicate based fixed prosthesis:
A
ant/ POST crowns, veneers, inlays, onlays, 3-UNIT ANT FDP
3
Q
consequences of tooth loss:
A
M-D drift of adjacent teeth, supraeruption of opposing teeth, premature contacts created during protrusive movements, alterations in occlusion, bone loss, possible loss of VD
4
Q
Options for replacing a missing tooth:
A
implant, PFD, RPD, Resin bonded FDP, no tx
5
Q
Comparison of survival rates of implants and FPD after 10y
A
about same
6
Q
Most common complication for conventional tooth-supported FDPs:
A
biological: caries, loss of pulp vitality
7
Q
Most common complication for implant-supported reconstructions:
A
technical complications
8
Q
caries under adjacent tooth for FP is considered a failure of:
A
the treatment
9
Q
For teeth w/ endo treatment, how does extraction and replacement w PFD compare w replacement w an implant supported prosthesis?
A
FDP lower longterm (10y same) survival than implant
10
Q
Aspects to eval when determining tx options for missing tooth:
A
edentulous area, perio health, caries on adjacent teeth, is occlusion stable?, root length and shape, bone support, divergent/ non-divergent roots (conical roots are the worst), quality and extension of caries/ restoration, H/W of edentulous area at MIP
11
Q
What always come before treatment?
A
disease control
12
Q
What needs to be eval if adj tooth to edentulous area has had an RCT and you are thinking about placing a FDP?
A
amount of ferrel
13
Q
Ante’s Law:
A
combined pericemental area of all abutment teeth supporting a FDP should be equal to or greater in pericemental area than tooth or teeth to be replaced
14
Q
Law of Beams:
A
deflection of force is proportional to the cube of its span
15
Q
What to do after diagnostic work-up and tx plan and before appt to start prepping tooth:
A
make shell for interim FDP and custom tray
16
Q
What to do after prepping adjacent teeth?
A
definitive impression, interocclusal record MCC/ACC shade and Interim restoration
17
Q
What to do after definitive impression interocclusal record MCC/ACC shade and Interim restoration
A
pindex, trim, mount the working cast, wax up, sprue and invest
18
Q
Metal alloy types that can be used for indirect:
A
III and IV
19
Q
Metal alloy type that can be used for short-span FPD:
A
III
20
Q
Type I alloy can be used for:
A
some, not all, inlays
21
Q
Type II alloy can be used for:
A
inlays and onlays
22
Q
Type IV alloys can be used for:
A
long span FPD, RPD
23
Q
How are metal alloys categorized?
A
yield strength and elongation
24
Q
Noble alloy:
A
25% noble, no stipulation for gold
25
Base metal alloy:
Less than 25% noble metal
26
Ti and TI alloy:
85%+ Ti
27
High noble:
at least 60% noble and at least 40% gold
28
3 types of porcelain:
opaque, body, incisal
29
Type of porcelain responsible fo rmetal-ceramic bond
opaque
30
Porcelain type that provides some translucency and contains metallic oxides that aide in shade matching:
body porceliain
31
Translucent porcelain type:
incisal porcelain
32
Factors affecting the bond:
oxide layer thickness, bonding agent, airborne particle abrasion, linear CTE
33
Higher flexure strength, metallic alloy or feldspatic porcelain?
metalic alloy
34
TF? Greater deflection leads to greater likelihood of breakage.
T
35
Is porcelain stronger in compressive or tensile strength?
compressive
36
CTE
Change in length per unit length of a material for every 1' temp change
37
Ceramic CTE:
13 -14 X 10^-6/C'
38
metal alloy CTE:
13.5-14.5 X 10^-6/C'
39
CCC reductions:
margin: 0.5mm, Non-functional cusp: 1mm, Functional 1.5mm
40
MCC reductions:
Lingual: 1mm (metal only), Buccal: 1.5mm (1.2mm porcelain, 0.3mm metal), Incisal 2mm (1.5mm porcelain, 0.5? metal) Non-functional cusp: 1.5mm, Functional 2mm
41
ACC reductions for anterior tooth:
Incisal: 1.5mm, Lingual / Facial: 1mm shoulder margin
42
ACC reductions for posterior tooth
Margin: 1.5mm, occlusal: 1.5-2mm, 1mm shoulder margin
43
3 PFM margin types:
knife edge, metal collar, porcelain margin
44
4 PFM Occlusal Surfaces:
metal lingual (anterior), porcelain lingual (anterior), metal posterior, porcelain posterior (?don't understand, check?)
45
PFM Ceramic Margin:
Gen only the labial area in esthetic zone, requires a smooth, 1.2mm finish line w round internal angle, slightly sub-gingival (equigingival), technique sensitive
46
Bur for PFM ceramic margin:
modified shoulder
47
Bur for metal collar PFM prep:
chamfer, 0.5 lingual reduction
48
Bur for knife edge PFM:
chamfer, right?
49
PFM metal ceramic margin:
mid-sulcus prep, acceptable result if fabricated properly, simplifies crown fabrication, many clinical problems
50
Clinical problems assoc w metal-ceramic margin PFM:
gingival over-contour, rough porcelain surface, non-esthetic after gingival recession NOT RECOMMENDED
51
When to use metal collar framework design for PFM
non-esthetic areas
52
Benefit of metal collar framework design for PFM
easier porcelain application
53
Issues with metal collar framework design for PFM
compromised appearance: shallow sulcus, thin gingival tissue, gingival recession
54
Which surfaces are covered in ceramic w Metal-Lingual/ occlusal PFM?
Facial, proximal, and incisal (?check? why?)
55
Benefit of Metal-Lingual/ occlusal PFM:
less tooth reduction (good for recovering bullics)
56
MI contacts are in this material for Metal-Lingual/ occlusal PFM:
metal
57
Which surfaces are covered in ceramic w Porcelain-Lingual/ occlusal PFM?
facial, incisal, lingual
58
MI contacts are in this material for porcelain-Lingual/ occlusal PFM?
porcelain
59
Disadvantage of Porcelain-Lingual/ occlusal PFM?
more reduction
60
In which material are proximal contact typically placed?
in porcelain, esthetics, easier to clean
| metal is a more conservative prep, but non-esthetic
61
Proximal contacts must be this far from Metal-Porcelain junction:
1.5mm
62
Adv of porcelain contact for Metal Ceramic Restoration:
easier to clean, if contact isn't heavy enough you can add porcelain
63
Incisal thickness must not exceed:
2mm
64
Requirements of framework design for PFM:
no unsupported porcelain, proper metal contour
65
*** Does this mean that if you over reduce we must add metal and porcelain in the same proportions so as not to decrease fracture resistance?
check
66
***** Slides say that a pontic "usually fills the space previously occupied by the clinical crown" When would it not?
ask, check
67
prep and design of abutment teeth for a PFD follow what design?
the same design as single crown restorations
68
Ideal characteristics of tissue in space that will be taken by pontic:
smooth, regular, attached
69
Class I Siebert Residual Ridge Classification:
dec ridge width, normal ridge height (hard and soft tissue)
70
Class II Siebert Residual Ridge Classification:
loss of ridge height, normal ridge width
71
Class III Siebert Residual Ridge Classification:
loss in both dimensions
72
if a pt comes in with a high smile line, which Siebert Residual Ridge Classification is easiest to correct the problem?
Class I (bc pt will continue to lose ht?)
73
Purpose of interim:
diagnose, assess tx plan chosen, can show pt what you are going for
74
FDP pontic, mucosal contact:
Ridge lap, modified ridge lap, ovate, conical
75
FDP pontic, no mucosal contact:
sanitary or modified sanitary (both hygienic)
76
2 types of pontics:
contact residual ridge or not
77
How to choose between the 4 types for mucosal contacts for FDP:
Bone loss
78
anterior, loss of width, want to treat pt, replace width by portion that wraps around, choose:
modified ridge lap
79
must have this for the ovate pontic to be an option
good amount of width
80
If patient comes w Class III bone loss, is there a way you can hide the length of the tooth?
Yes, 1. Replace tissue w pink porcelain 2. change line angle, create illusion 3. surgical intervention (non-prosthetic)
81
Saddle-ridge lap, recommended or not?
not
82
Recommendation location for sanitary/hygienic:
posterior mandible
83
Recommendation location for conical:
Molars w/o esthetic requirement
84
Recommendation location for modified ridge la[p:
High esthetic requirements (ant, premolars, some max molars)
85
Recommendation location for ovate:
very high esthetic requirements, max incisors, canines, and premolars
86
Material options for conical PFD:
metal-ceramic, all-resin, all-metal (no all ceramic)
87
Material options for modified ridge lap & ovate
metal-ceramic, all-resin, all ceramic (no all metal)
88
ovate portion of FDP pontic has to go
2-3mm apical to margin of extraction site
89
How to preserve gingival architecture at time of tooth removal:
Immediate resto and perio intervention, PFD pontic 2.5mm apical to facial free gingival margin
90
Biological considerations regarding pontic:
cleansable tissue surface, access to abutment teeth, no pressure on ridge, pontic material, occlusal forces
91
Most biocompatible pontic material:
glazed porcelain
92
FDP mechanical considerations:
RIGID resist deformation, STRONG, prevent fracture, metal-ceramic framework, RESIST porcelain FRACTURE
93
Differences bw rigid and non-rigid connectors:
rigid: can't separate from one and other, non-rigid - key/ lock, usually graduate level
94
3 types of rigid connectors for FDP'a
Cast, Soldered/Welded, Loop
95
Aspects of the FDP connector that influence success of the prosthesis:
size, shape, and position
96
Why connectors shouldn't be too large or small:
impedes cleaning / may be visible, more prone to fracture
97
Type of failure that will occur if connector is too large incisal/ cervically
periodontal failure
98
May lead to the visibility of the connector:
too large, inappropriate shaping
99
A properly shaped connector has a configuraion similar to:
a meniscus formed bw the 2 parts of the prosthesis
100
Tissue surface of connector:
highly polished, curved F-L to facilitate cleansing
101
Shape of connector M-D:
shaped to create a smooth transition from one partial FDP component to the other
102
Shape of most connectors in B-L cross-section:
elliptical, strongest if major axis parallels direction of force, usually not possible due to space constraints, usually must be perp
103
Crown types, best to worst mechanical retention of pontic:
porcelain only on B, por on B/occlusal = por on B/cervical margin, then all porcelain except M/D contacts/cervical lingual area
104
An esthetic pontic should appear to:
emerge out of edentulous ridge
105
Connector is always placed more towards the (B/L):
L
106
Strongest connector is in this direction in relation to force:
major axis of ellipse parallels direction of force
107
Space occupied by connectors:
normal anatomic interproximal contacts, ant more toward lingual embrasure for esthetics
108
Limiting factors in design of non-rigid connectors:
pulp size and clinical crown height
109
Most prefab patterns for connectors require:
the prep of a fairly large box to allow incorporation of mortise in the cast resto wo overcontouring interproximal emergence profile,
110
Recommended vertical ht of clinical crown to ensure adequate strength of FDP:
3-4mm
111
Indications for loop connectors:
to keep a diastoma
112
Disadv of loop connector:
poor plaque control, lower strength
113
Indications for non-rigid connector:
Intermediate (pier) abutment, no common POIt, complex man FDP's
114
Another name for intermediate abutment:
pier abutment
115
how to deal w very M tilted abutment tooth when fabricating FDP:
non-rigid connector w crown on M tilted tooth: can't correct tilt by having rigid abutment, don't have a good POI, prefer to have a
116
How are forces on teeth affected by a non-rigid connector?
They control amt of force applied to abutment
117
Parts of non-rigid connector:
mortise (female, matrix), tenon (male, patrix)
118
Patrix is w/in:
the contours of the retainer
119
Patrix is attached to:
pontic, fits into matrix
120
Limiting factors for non-rigid connectors:
edentulous span, pulp size (need receded pulp, can't do on younger pts), crown ht: 3-4mm O-G ht recommended
121
The less convergence of the prepped teeth for a FDP the:
greater the retention
122
Retention def:
removal along POI or long axis
123
Essential element of retention:
2 opposing vertical surfaces of the same prep
124
Resistance def:
forces directed in apical or oblique direction
125
TF? The addition of grooves or boxes to a prep w a limited POI greatly increases its retention.
F. bc the sa is not increased sig
126
Boxes are good for increasing:
resistance form bc they interfere w rotational movement (tipping) of crown
127
To increase retention/ resistance if we tapered too much:
buccal groove or other internal features
128
Teeth that can often benefit from grooves and/or boxes:
M tipped molars, short premolars
129
To inc retention/ resistance of an over reduced premolar"
grooves or boxes (are all grooves placed on B? if so, why?)
130
List all pt positionings:
12: max occlusal, 10-11: pt facing you, 9: pt facing away from you, 8-9: man ant
