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WorksheetsFixed 1 Midterm
Total questions: 76
Worksheet time: 57mins
The full-coverage crown and its preparation:
may protect weakened tooth structure
requires more tooth structure removal than an intercoronal restoration
encircles all the remaining coronal tooth structure
A and C
A, B, and C
Indications for placement of a full-coverage crown may include:
teeth with large existing restorations
cracked tooth
broken cusps
the patient desires a more esthetic tooth
all of the above
Which of the following is NOT one of the principles of tooth preparation?
preservation of the periodontium
preservation of the pulpal innervation
preservation of tooth structure
retention and resistance form
marginal integrity
4. ____________ prevents dislodgment of a restoration by forces directed in apical or oblique directions.
resistance
retention
abrasion
adhesion
Crown preparations are tapered (converge occlusally) to:
allow us to visualize the preparation walls from the occlusal direction
eliminate axial wall undercuts
create maximal retention for the preparation
A and B
A, B, and C
The acceptable range for crown preparation convergence of the total axial walls in our course is _____ degrees.
0-10
0-16
5-20
6-16
10-20
While longer axial wall lengths are generally more retentive, the minimal axial wall length should be _____ mm.
2-3
3-4
4-7
5-8
6
__________________ is the imaginary line in which a restoration can be placed onto or removed from a preparation.
resistance form
path of insertion
freedom of displacement
principle of substitution
structural durability
The complete gold crown (full gold crown) preparation should include each of the following reduction guidelines EXCEPT one. Which one is the EXCEPTION?
1.0 mm on the non-functional cusp
1.5 mm on the functional cusp
0.7-1.0 mm buccal and lingual axial reduction
0.7-1.0 mm chamfer thickness
0.3-0.5 mm chamfer thickness
The Exaflex putty impression prior to beginning tooth preparation for a full gold crown:
is made with a vinyl siloxane impression material
is used as a mold for the provisional crown restoration that is placed at the end of the preparation appointment.
is used to form the wax pattern for the full gold crown
A and B
A, B, C
The fixed prosthodontics custom tray is different from the complete denture custom tray in which way(s)?
the material the tray is made from
the number of layers of wax used as a spacer
the extension toward the vestibule
A and B
B and C
In the IUSD clinics a full-arch custom tray is required for preparation for:
the most distal tooth in the arch
inlays or onlays on posterior teeth
any full-gold crown preparation
The tray stops on the custom tray for fixed prosthodontic impressions are to:
allow for proper thickness of the impression material
prevent overseating of the tray
avoid contact b/w the tray and an area of occlusal contact on the teeth
A and C
A, B, and C
A full gold crown is contraindicated when:
greater retention is necessary
greater resistance is necessary
esthetics is the prime concern
occlusal plane modification is necessary
all of the above are contraindications:
Buccal and lingual depth cuts should be placed to a depth of 0.7-1.0 mm at the cervical margin
True
False
Tilting the handpiece and bur as you are removing axial tooth structure may result in:
over-tapering the tooth preparation
creating undercuts in the tooth preparation
over-reducing the tooth preparation
A and C
A, B, and C
When equilibrating the Fixed dentoform, which of the following types of occlusion is utilized to establish posterior teeth protecting anterior teeth in centric closure and anterior teeth discluding posterior teeth in any eccentric movement?
bilateral balanced occlusion
unilateral balanced occlusion
mutually protected occlusion
group function occlusion
both A and D are used for equilibration of the Fixed dentoform
Statement 1: The functional cusps are the cusps of posterior teeth that endure the greatest occlusal forces and seat into an opposing fossa or occlusal embrasure. Statement 2: In Angie's Class I occlusal relationship, the buccal cusps of tooth #19 are the functional cusps.
both statements are true
the first statement is true; the second statement is false
the first statement is false; the second statement is true
both statements are false
Centric occlusion is the occlusion of opposing teeth when the mandible is in centric relation. To prevent harmful tipping forces, the forces of occlusion are best directed perpendicular to the long axis of each tooth
both statements are true
the first statement is true; the second statement is false
the first statement is false; the second statement is true
both statements are false
When utilizing the proper occlusal concept, which of the following teeth should ideally contact when the mandible moves laterally (side to side)?
4
11
22
B and C only
A, B, and C should contact during an eccentric movement
Which of the following circumstances would a patient's treatment plan include a fixed restoration as an option?
fractured tooth with large previous restoration
anterior tooth which is discolored due to trauma
replacement of a missing tooth #12 using #11 and #13 as abutments for a fixed partial denture
A and B only
A, B, and C
There are several available materials to choose from when treatment planning a fixed restoration. Which of the following materials provides the most esthetic restoration but requires the most overall reduction of tooth structure when compared to the other materials?
cast metal
metal ceramic
all ceramic
porcelain fused to a metal substructure
B and D only
23. Statement 1: A partial prosthesis helps restore missing teeth with pontic restorations which are also known as abutments. Statement 2: Restoring teeth with fixed restorations should allow for optimum function while minimizing trauma to supporting structures.
both statements are true
the first statement is true; the second statement is false
the first statement is false; the second statement is true
both statements are false
For a patient treatment planning appointments for multiple fixed restorations, it is advised to create the final treatment plan and sequence followed by fabricating diagnostic casts. Making a correct diagnosis is a prerequisite for formulating an appropriate treatment plan and requires only dental information be obtained prior to treatment.
both statements are true
the first statement is true; the second statement is false
the first statement is false; the second statement is true
both statements are false
25. Statement 1: Diagnostic casts will display a dynamic relationship of the teeth to be examined without interferences present only if the casts are mounted on an adjustable articulator. Statement 2: Diagnostic casts provide essential information necessary for treatment planning and procedures related to other dental disciplines such as periodontics, dental implants, and oral surgery.
both statements are true
the first statement is true; the second statement is false
the first statement is false; the second statement is true
both statements are false
Alginate material is utilized for impressions to fabricate diagnostic casts. Which of the following accurately describes alginate?
irreversible hydrocolloid
salts react with sodium sulfate to produce a one way chemical reaction
consists of calcium and potassium salts of alginic acid
A and B only
Which of the following is considered an advantage of alginate impression material?
low cost
faster set than other impression materials
provides surface details necessary for definitive casts and dies
A and B only
A, B, and C
Select the proper sequence of steps for an alginate impression technique.
1. Apply alginate tray adhesive
2. Place the stock tray into the patient's mouth to select proper size and verify fit
3. Add mixed alginate to tray loading from the posterior aspect of the tray
4. Add the correct amount of powder to the mixing bowl
5. Orient and seat impression tray with alginate into the patient's mouth
6. Add the correct amount of water to the mixing bowl
7. Manually mix the water and powder mixture
1, 2, 4, 6, 7, 3, 5
1, 2, 6, 4, 7, 3, 5
2, 1, 4, 6, 7, 3, 5
2, 1, 6, 4, 7, 3, 5
All of the above sequences are correct
During the alginate impression technique, the clinician should only hold and apply pressure to the tray handle as the impression is seated and throughout the setting process. To remove the set impression material and stock tray from the patient's mouth, carefully remove it with a quick snap in the direction of the long axis of the teeth.
both statements are true
the first statement is true; the second statement is false
the first statement is false; the second statement is true
both statements are false
When pouring an alginate impression with dental stone, which of the following is the maximum time suggested to prevent an alginate impression material from distortion following removal from a patient's mouth?
2 min
12 min
45 min
60 min
65 min
31. Statement 1: Proper technique for pouring alginate impression with dental stone is to manually mix the stone mixture followed by vacuum mixing. Statement 2: After mixing is complete, a small amount of dental stone is placed into the impression while rotating the impression allowing the stone to flow throughout the surfaces.
both statements are true
the first statement is true; the second statement is false
the first statement is false; the second statement is true
both statements are false:
Provisional restorations are an essential step when fabricating many types of fixed indirect restorations. Which of the following requirements is associated with the provisional sealing and insulating the prepared tooth surface from the oral environment to prevent tooth sensitivity and further irritation to the pulp?
biologic
mechanicl
function
esthetics
Statement 1: Custom made provisional restoration can be fabricated utilizing a matrix in the form of impression material, moldable putty or a vacuum-formed template. Statement 2: If the pre-operative teeth do not have proper contours, a matrix can be fabricated from a diagnostic wax-up
both statements are true
the first statement is true; the second statement is false
the first statement is false; the second statement is true
both statements are false
Which of the following provisional restorations must be relined and cannot be utilized for multiple connecting provisional restorations?
custom made restoration
prefabricated restoration
polycarbonate restoration
B and C only
A, B, and C
Which of the following provisional materials is a micro-filled composite?
Alike
Snap
Protemp
Triad
none of the above
Provisional restorations are fabricated using a variety of materials and methods. Which of the following methods beginning steps includes conservative preparations performed on the articulated mounted stone casts?
direct technique
indirect technique
combination technique
in-combination technique
none of the above
When fabricating provisional restorations, the direct technique has the most risk for tissue and pulpal trauma while the indirect technique as little to no risk of tissue and pulpal trauma. For the marginal adaptation when forming the initial provisional shell, good marginal fit with little to no modification is another advantage when using the indirect technique.
both statements are true
the first statement is true; the second statement is false
the first statement is false; the second statement is true
both statements are false
Which of the following provisional restoration features helps prevent leakage of saliva which may cause tooth sensitivity?
properly contoured emergence profile
tripod occlusal contacts
well adapted margins
tight proximal contacts
A and B only
Statement 1: An emergence profile is a thin overextension of material present past a finish line of the tooth preparation. Statement 2: A large over-extension of material extending out from a finish line of a tooth preparation is referred to as an enamel ledge.
both statements are true
the first statement is true; the second statement is false
the first statement is false; the second statement is true
both statements are false
When fabricating direct provisional restorations utilizing methacrylate resins, the matrix and the temporary material should be removed from the tooth before complete polymerization occurs to avoid locking of the provisional into the embrasure spaces and to avoid pulpal damage. When assessing the final occlusion of a fixed provisional restoration, the result should be the patient's overall dentition has the same occlusal contacts with and without the restoration in place.
both statements are true
the first statement is true; the second statement is false
the first statement is false; the second statement is true
both statements are false
Statement 1: A medium-bodied PVS impression material exhibits higher viscosity when compared to a light-bodied impression material. Statement 2: The light-bodied impression material is used to load the impression tray.
both statements are true
the first statement is true; the second statement is false
the first statement is false; the second statement is true
both statements are false
Prior to a PVS impression making, tray adhesive is applied to the appropriately selected tray. Which of the following describes PVS tray adhesive and its application?
forms a chemical bond to the tray and the impression material
alginate tray adhesive can be substituted if the clinician does not have PVS adhesive
an impression should be taken immediately following the application of the adhesive
all of the above statements correctly describe PVS tray adhesive and its application
none of the above statements correctly describe PVS tray adhesive and its application
In which of the following circumstances is it highly advised to place periphery wax within the gingival embrasure spaces prior to performing a PVS impression?
a patient with mobile teeth due to periodontal disease
a patient with multiple fixed partial dentures
a patient with recession around posterior molars with little to no interproximal dental papilla
A and C only
A, B, and C
Statement 1: A technique for displacement of gingival tissues involves the placement of a retraction cord within the gingival sulcus which displaces the tissue laterally. Statement 2: The use of hemostatic agents can help with fluid control to maintain a dry field of operation.
both statements are true
the first statement is true; the second statement is false
the first statement is false; the second statement is true
both statements are false
When choosing a material for the fabrication of dies and working casts, which of the following would NOT be an ideal requirement of the given material?
dimensional accuracy
compatible with impression materials
abrades easily
easily sectioned
none of the above
Statement 1: For dental gypsum, calcination is a process which silica of crystallization is removed when heating the dihydrate to produce the hemihydrate. Statement 2: Type IV dental gypsum is a higher strength stone than Type III dental gypsum.
both statements are true
the first statement is true; the second statement is false
the first statement is false; the second statement is true
both statements are false
Which of the following die fabrication methods requires creating individual dies and a separate working cast displaying the tooth preparation?
removable die technique
multiple pour technique
alternate die technique
A and C
A, B, and C
When fabricating stone dies, the first stone pour is only in the area of the tooth preparation and should be used as the #2 die. The working cast helps with the development of axial contours, proximal contacts, and the final margination of the wax pattern.
both statements are true
the first statement is true; the second statement is false
the first statement is false; the second statement is true
both statements are false
Which of the following is accurate information regarding gypsum stone dies?
the dies must be trimmed using dry methods
the handle of the trimmed die should be parallel to the long axis of the tooth
the trimmed die handle should be visible from the occlusal surface
A and B
A, B, and C
Statement 1: An arcon articulator has the condylar element on the lower member of the articulator, simulating the mouth. Statement 2: Arbitrary facebows use average values of the true hinge axis determined by the manufacturer.
both statements are true
the first statement is true; the second statement is false
the first statement is false; the second statement is true
both statements are false
Which of the following articulators contains an angle between the condylar inclination and the occlusal plane of maxillary teeth which remains constant in both the open or closed position and can produce the patient's eccentric movements?
acron
non-acron
hinge
A and B only
all of the above
Which of the following statements regarding facebows is true?
A facebow is used to orient the mandibular cast to the hinge axis of the maxilla
Records anteroposterior and mediolateral spatial position of the maxillary occlusal surfaces
An arbitrary facebow is within 10 mm of the true hinge axis.
B and C only
all of the above are true
53. Statement 1: When using a facebow, it is advised to secure the facebow in the desire position followed by positioning the bite for within the patient's mouth Statement 2: When mounting the maxillary cast, it is important the upper member of the articulator rests directly on the horizontal cross bar of the facebow
both statements are true
the first statement is true; the second statement is false
the first statement is false; the second statement is true
both statements are false
Which of the following statements is true regarding an interocclusal relation record for an indirect restoration?
the record allows for stability between the maxillary and mandibular arches
the record must cover all occlusal surfaces teeth to aid in holding the casts during mounting
the record should be trimmed to avoid contact with soft tissue
A and C only
B and C only
Which of the following steps are performed on the working cast when creating a wax pattern for an indirect posterior restoration?
final margination of wax pattern
developing the proper emergence profile
fabrication of the coping
B and C only
none of the above
Which of the following is true regarding proximal contacts?
each proximal contact area contains two embrasure spaces
an absent proximal contact may lead to tooth drifting and food impaction
proximal contacts are generally located in the gingival 1/3 of the crowns with the expectation of maxillary molars
A and B only
A, B, and C
57. Statement 1: Over-contoured restorations with large convexities promote accumulation of food debris and plaque. Statement 2: An emergence profile extends from the gingival margin to the height of contour ideally producing a concave profile in the gingival third of the axial surface.
both statements are true
the first statement is true; the second statement is false
the first statement is false; the second statement is true
both statements are false
Statement 1: The anteroposterior curvature of the occlusal plane is called the curve of Wilson. Statement 2: The curve of Wilson allows for mandibular cusps becoming longer further distally and the maxillary cusps becoming shorter.
both statements are true
the first statement is true; the second statement is false
the first statement is false; the second statement is true
both statements are false
Which of the following are *true* statements regarding investing wax patterns?
the sprue should be larger in diameter than the thickest part of the wax-up
the wax pattern needs to be centered in the middle of the ring
heating the investment must be gradual to allow steam to escape
the purpose of investing is to create a mold duplicating the wax pattern that compensates for the shrinkage of the wax and cast alloy
all of the above are true statements
What is the minimum distance required from the highest point of the wax pattern to the end of the investment ring?
2 mm
3 mm
6 mm
10 mm
15 mm
When evaluating the cast, which of the following best explains random porosities present throughout the casting?
debris present within the wax pattern
rapidly heating the investment
air trapped during investing
dropping the casting ring
none of the above
For fitting an indirect restoration following the casting procedure, the restoration should be placed initially on the #1 die to evaluate the marginal adaptation. A reason for polishing an indirect casting restoration is to create a smooth surface which helps decrease plaque accumulation.
both statements are true
the first statement is true; the second statement is false
the first statement is false; the second statement is true
both statements are false
A die spacer is often used as a method for internal surface adjustment when fabricating indirect restorations. Which of the following is a *FALSE* statement regarding die spacer?
Die spacer is less dangerous when compared to electrochemical milling.
Die spacer creates a smooth internal surface but results in poor retention of the restoration
Die spacer is only indicated for preparations with minimal axial wall height
A and C only
all of the above are false statements
When evaluating proximal contacts, the ideal contact intensity should be when one piece of shimstock slides through the contact while two pieces of shimstock holds within the contact. When adjusting the occlusal contacts of a posterior indirect restoration, all centric contacts should be eliminated.
both statements are true
the first statement is true; the second statement is false
the first statement is false; the second statement is true
both statements are false
A patient presents for a full gold crown placement appointment. The patient medical history was reviewed and there were no changes. The patient states she has been experiencing a dull toothache when chewing following the crown preparation appointment 3 weeks ago. Select the next appropriate action for the above patient case:
Administer anesthetic, remove the provisional restoration and cement the definitive restoration.
Evaluate the provisional restoration for occlusal interferences or open margins and make necessary adjustments, and monitor over time to see if symptoms persists.
Refer the patient immediately for endodontic therapy.
Answers B and C only
Answers A, B and C are all appropriate actions
Viscoelastic behavior is characterized by:
a stress-strain relationship that remains constant as the rate of loading changes.
a stress-strain relationship that changes as the rate of loading changes.
behavior that mimics that of elastic materials.
behavior that mimics that of viscous materials
When using an addition silicone impression material, which of the following scenarios does NOT require the use of a custom tray?
Impressing a three-unit bridge from the maxillary right canine to maxillary right central incisor
Impressing a mandibular Kennedy Class I removable partial denture
Impressing a full coverage crown for a maxillary right first molar in a fully dentate individual.
Impressing a full coverage crown on a mandibular left third molar
Post-impression stability of polysulfide is decreased because of:
imbibition.
syneresis.
spraying with disinfectants.
evaporation of volatile by-products
Control of dimensional changes due to polymerization contraction when using polysulfide impression materials is accomplished by:
using a custom tray.
using a putty viscosity in a stock tray.
using a heavy body viscosity in a stock tray.
delaying pouring for 24 hours
An appropriate method for changing the setting time of alginate is to:
change the temperature of the water.
decrease the water/powder ratio.
increase the water/powder ratio.
replace some of the powder with gypsum
Undercuts should be blocked out when using polyether impression materials BECAUSE polyether is the most flexible of the non-aqueous elastomers.
Both the statement and the reason are correct and related.
Both the statement and the reason are correct and NOT related.
The statement is correct but the reason is NOT.
The statement is NOT correct, but the reason is correct.
NEITHER the statement NOR the reason is correct
The form of silica that provides the most expansion when heated to 700°C is:
cristobalite.
fused quartz.
quartz.
tridymite
If decreased expansion is desired when investing with a phosphate-bonded investment material, the amount of special liquid that is included in the mix should be:
decreased.
increased
One of the primary functions of an investment is to compensate for the net contraction of the metal as it solidifies and cools to room temperature
True
False
Compared to gypsum-bonded investments, phosphate-bonded investments are much stronger and can withstand much higher temperatures
True
False
Gypsum-bonded investments should be heated to temperatures over 750°C to break down the binder
True
False
