Prosthetics MCQ Flashcards
What is the spacer foil in the plastic shell coping method(adapta) used for?
- Spacer for cement
- Easier workability
What’s the thickness of the base foil in the plastic shell coping method (Adapta)?
0.6 mm
The vestibular wall on the metal-acrylic crowns shouldn’t be less than:
0.3 mm
Which stages of the ceramic sintering is done with vacuum?
- Placement of the opaque layer
- Placement of the enamel layer
- First correction of the ceramic
Which part of the prepared full veneer crown tooth is the widest ?
The cervix
Name 4 pontic design profiles
- Hygienic
- Ridge lap
- Modified ridge lap
- Ovate
Where on the wax pattern is the sprue usually attached?
On a lingual cusp
Which gingivo-occlusal third of the connection between the retainer and the pontic
should be wax free?
gingival third
Name at least three different kinds of ceramic layers (for a metal ceramic restorations)
Dentine, enamel, opaque
At what depth could the marginal edge enter in the gingival groove?
0.3 – 0.5 mm
What kind of retentions can be used when preparing metal restoration with acrylic veneering material?
- Small pearls
- Wax retention
Name at least 3 systems for preparing working casts with removable dies
- Straight dowel pin
- Curved dowel pin
- Pindex system
The emergence profile is the perpendicular distance between the tip of a cusp and its base plane
false
The external surface of the cemented restoration should create as nearly a perfect uninterrupted transition from restorative material to tooth as
possible
true
Hardest of all abrasives
DIamond
incorporated into pastes for use on brushes or cloth wheels
Tripoli, Rouge
Name at least three finish line configurations for full veneer crown preparation
- Feathered edge/knife edge
- Chamfer
- Shoulder
What is the base foil in the plastic shell coping method (Adapta) used for?
It’s used as a base for the was pattern
What’s the thickness of the spacer foil in the plastic shell coping method (Adapta)?
0.1 mm
The cervical wax in the Adapta method is placed
between the edge of the base foil and the preparation margin
How should a prepared tooth look like?
The axial walls should converge occlusally 2-6 degrees
Name the parts of a fixed bridge prosthesis
Abutment, retainer, pontic and connector
Which stage of the ceramic sintering procedure is done without vacuum?
Placement of the glaze
The channel through which metal is cast into a mould is called
Sprue
To provide adequate bulk of alloy during solidification, the sprue itself should be no longer than:
6.0 mm
Where on the wax pattern is the sprue usually attached?
On a lingual cusp
Name at least 3 systems for preparing working casts with removable dies
Dowl pin technique, di lock tray, pindex
Polishing metals and ceramics done with
Rubber wheels, pastes, brushes
Finishing and polishing starts with
An abrasive that is coarse enough to remove gross irregularities
Which part of the prepared full veneer crown tooth is the widest ?
The cervix
At what depth could the marginal edge enter the gingival groove
0.3 – 0.5 mm
According to the Kennedy classification system for edentulism class I represents:
Bilateral posterior edentulous area
Major connector and direct retainer are parts of the removable partial denture
True
The lingual bar is a mandibular major connector
True
Lingual bar shape
Pear shape
Lingual bar superior border distance from free gingival margin
3mm
The complete and modified palatal plate have wide application, but mostly to
Class I and Class II
Name the parts of a direct retainer
- Retentive arm
- Reciprocal arm
- shoulder
- body
- Rest
occlusal rests transfer stresses to the abutment tooth
True
The impression surface of a complete denture is
The intaglio surface
The custom tray is fabricated using
The diagnostic cast
Correct sequence of lab steps in fabrication of acrylic complete denture
diagnostic casts, master casts, base plates and occlusal rims, mounting on an articulator,
arrangement of the artificial teeth, wax-up, flasking, curing, finishing
The correct position of maxillary central incisor according to Gysi is
saggital plane 0º, frontal plane 5-8º, the incisal edge touches the occlusal plane
Components of a complete denture
Denture base, flanges, denture borders and artificial teeth
What is/are the function/s of the denture base
Support and retention
Artificial teeth can be made of
acrylics, porcelain and resin
The external surface of the lingual/ buccal/ labial flanges of the denture refers to
The cameo surface
Describe the curve of spee
An imaginary anteroposterior curve beginning from the tip of the canines, following the buccal cusp tips of posterior teeth and continuing to the anterior border of the ramus
The arrangement of maxillary molars forms both the curve of spee and the curve of Wilson
True
According to Gysi which of the maxillary teeth are above the glass plate
lateral incisions and second molar
Arrange in correct order the cusps of the maxillary first molar starting with the cusp
which is closest to the glass plate
mesiolingual cusp, mesiobuccal cusp, distolingual cusp, distobuccal cusp
What is the most common problem when packing a two-part mould in the conventional
manner
increase in vertical dimensions
When using conventional cuvette technique acrylic is processed by
injecting
Dewaxing procedure is done
to remove the wax in the wax pattern so that a mould space is made for acrylic to fill in
to remove the wax in the wax pattern so that a mould space is made for acrylic to fill in
- Establish vertical dimension
- Determine centric relation position
- No cast to cast contact at the posterior end of the rim
Finishing and polishing the dentures include
trimming, sand papering, pumice wash
In special trays the border of the tray must be shorter than the posterior palatal seal area ( an area between the
soft and hard palate
False
.What’s the function of the retentive arm (clasp)
provides resistance to vertical displacement of the rpd
What is the level of the wax in the final wax up of the dentures in the area of the
premolars
till the height of contour
Name at least 4 components of the removable partial denture
-Major connector
-Minor connector
-Rest
-Direct retainer
-Indirect retainer
-Attachment
-Denture
base
-Tooth replacement
The custom tray is fabricated using
the diagnostic cast
the anatomic curve established by the occlusal alignment of the teeth in the median plane
The compensating curve of Spee
The arrangement of maxillary molars forms both the curve of spee and the curve of Wilson
True
Working with Pindex system, the pins are placed
after the plaster sets
Working with Adapta, system, no pins are used
True
Write down the main components of any FPD
Retainer, Pontic, Connectors, Abutment
Write down the main components of any direct retainer
Retentive arm, reciprocal arm, shoulder, body, rest
If the patient needs prosthetic treatment with both fixed and removable prosthesis, the fixed restoration (full coverage crowns, bridges) will be fabricated first
True
What is the correct sequence of ceramic layers when a metal-ceramic crown is
Opaque, dentine, enamel, translucent
The noble metals are used in CAPTEK coping are
Gold, platinum, palladium
The CAPTEK coping is fabricated by
firing in a porcelain furnace on a refractory die
What kind of restoration could be manufactured using CAD/CAM technology
All of them
During sintering zirconium dioxide undergoes the following changes
Volume is decreased, strength is increased
Which technology is suitable for dental ceramics
layering technique, pressing technique, CAD/ CAM
Lithium disilicate ceramics for press techniques could be used for manufacturing
Veneers, partial and complete crowns
Which type of dental gypsum is suitable for working models (crowns, bridges)
. type 4 dental stone
Retention and stability of removable partial dentures are achieved by
Clasps
When proximal surfaces of adjacent teeth diverge from an area of contact, an
embrasure is formed
lingually, facially, occlusally and cervically
Polyethers belong to the group of
elastomers
Stock trays are
are used for taking a preliminary impression
The main body and the catalyst for additive silicons are mixed in
non-equal volumetric and weight proportions
Which impression material is electroconductive
C-silicons
When a model with preserved gingival contour is made for an implant case, the first
thing that is poured into the impression is
gingival mask
Properly planned dowel core restoration, requires that
the length of the dowel should be equal or longer than the length o f the future crown
In master-cast duplication method the wax pattern is
not removed from the model for casting
Which of the following methods for fabrication metal free crowns is based on melting
the crystalline structures of the ceramics
pressed ceramics
Bilateral posterior edentulous area according to Kennedy’s classification are
class 1
Precision attachments are made of
both patrix and matrix= precious alloy
Which attachment is not a stock attachment
Telescopic crown
When a model with preserved soft gingival contour is made, for implant cast, the soft
material
is poured directly in the impression before pouring the plaster
The function of the reciprocal arm of a direct retainer is
to stabilize the tooth
A Major connector
connects the components of RPD
Clasp retainers
can be done both ways, by casting and bending
Dentoalveolar clasps
are made of the same material as the denture base
the first stage of planning of direct retainer, a surveyor is used for determining the
depth of the undercuts
Which of the following equators, can be manipulated and altered
prosthetic equator
The master cast duplication method requires
duplication of the plaster model and replacement with investment material
Write the four components of dowel core:
Core, Dowel, Crown, Ferrule, Tooth
What pontic is commonly used for aesthetics requirement
Ovate pontic
Polyether is what type of impression material?
- Replicating material, hydrophilic elastomeric impression material
- Polyethers have good elastic properties and are particularly suited for implant prosthodontics.
What cannot be milled?
-Telescopic crown are mille-d ! Stock attachments (cannot be milled because they are prefabricated
Horizontal distance between cutting edges of the upper and lower teeth
overjet
Vertical distance between the cutting edges of the upper and lower teeth
overbite
The mechanism of connection of the metal cap and the porcelain is realized by:
Mechanical bonding, CTE, Van der Waals forces, chemical bonding
Indirect Retainers are also called
Kipmayders
The arrow-shaped angle obtained by using a graphical registration of the movements of
the lower jaw corresponds to
Gothic angle
By which class of the Kennedy classification is a unilateral limited defect in the dentition
III class
