Dental Materials Flashcards
Jello is an example of a/n
A. Reversible hydrocolloid
B. irreversible hydrocolloid
Reversible hydrocolloid
Alginate is an example of a/n
A. Reversible hydrocolloid
B. irreversible hydrocolloid
Irreversible hydrocolloid
Hydrocolloid is an example of a/n A. Reversible hydrocolloid
B. irreversible hydrocolloid
Irreversible hydrocolloid
Instant pudding is an example of a/n
A. Reversible hydrocolloid
B. irreversible hydrocolloid
Irreversible hydrocolloid
The main potential hazard of mercury hygiene is in the form of mercury vapor
A. True. B. false
True
Decontamination of a room is possible after a Mercury spill only if the operatory is carpeted
A. True B. false
False
Cohesive gold is the only metal still used in its pure state in dentistry.
A. True. B. false
True
TMS pins need to be cemented into place.
A. True. B. false
False
Posts need to be cemented into place.
A. True. B. false
True
The best cement to use as a temporary filling on a sensitive tooth is: A.Polycarboxylate cement
B. zinc phosphate cement
C. calcium hydroxide
D. zinc oxide and eugenol
Zinc oxide and Eugenol
The best cement to use as a base under a permanent filling on a tooth which is not sensitive is: A. Polycarboxylate B. zinc phosphate C. Calcium hydroxide D. Zinc oxide and Eugenol
Zinc phosphate
The best material to use to cement orthodontic brackets to a tooth is: A. Polycarboxylate B. zinc Phosphate C. Calcium hydroxide D. Zinc oxide and Eugenol
Polycarboxylate
Zinc oxide and Eugenol can be used as a permanent filling if it is mixed thick.
A. True B. false
False
Which of the following dental cements is the least irritating to the pulp? A. Calcium hydroxide B. ketac- cem C. Flecks with Vaseline D. Zinc phosphate
Calcium hydroxide
It is a good idea to line a preparation with cavity varnish before a composite filling is placed on a sensitive tooth.
A. True B. false
False
What speeds up the formation of secondary dentin? A. Calcium hydroxide B. carboxylate C. Zone D. Zinc phosphate
Calcium hydroxide
Amalgam may be irritating to the pulp.
A. True
B. false
True
If there is a small exposure to pulp, the first thing to do would be:
A. Endodontic treatment
B. placement of ZOE
C. Placement of calcium hydroxate
Placement of calcium hydroxide
After placing ZOE in a tooth that has been sensitive, it is best to wait —- before placing a permanent restoration
A. 3days B. 4 wks
C. 2 wks. D. 3 wks
3 weeks
If composite is handled with metal instruments, the material may: A. Not be affected B. turn gray C. Turn brown D. Become more brittle
Turn gray
If polycarboxylate is mixed or handled with metal instruments, the material may: A. Not be affected B. turn gray C. Turn brown D. Become more brittle
Not be affected
Zinc Phosphate cement is soothing to the pulp.
A. True. B. false
False
This material is placed on the inner surface of the cavity prep to seal dentinal tubules on the exposed dentin and to prevent marginal leakage.
A. Dycal. B. temprex
C. Flecks D. Copalite
Copalite
If a patient had a temporary crown seated with temp bond and it came off within a day or two, and the tooth was not sensitive, it should be reseated with:
A. Flecks. B. flecks w/ Vaseline
C. Zone. D. Temrex
Flecks w/ vaseline
Derlon should be mixed on a glass slab
A. True
B. false
False
Para post should be cemented into place with ZOE
A. True
B. false
False
Dycal and Zone can be mixed interchangeably.
A. True
B. false
False
Watercooled trays are used to carry which impression material? A. Elastomeric material B. irreversible hydrocolloid C. Reversible hydrocolloid D. Impression plaster
Reversible hydrocolloid
Syneresis is the A. Uptake of water B. loss of water C. Expansion of rubber base D. Amount of elasticity in an impression
Loss of water
Imbibition is the: A. Uptake of water B. loss of water C. Expansion of rubber base D. Amount of elasticity in an impression
Uptake of water
Under mixing irreversible hydrocolloid impression material results : A. Grainy mix w/ poor details B. increased tear strength C. Increased setting time D. Finer surface detail
A grainy mix with poor detail
The effect of zinc oxide and Eugenol on the pulp is:
A. Irritating B. sedating
C. Has no effect
D. To control bleeding
Sedating
Why is zinc oxide and eugenol cement mix on a paper pad?
A. To prevent the material from setting too fast
B. To increase the setting time
C. To make cleaning easier
D. To decrease the setting time
To make cleaning easier
What is the consistency of zinc oxide and eugenol cement when it is used as a temporary restoration?
A. Fluid. B.firm and brittle
C. Putty-like. D.Smooth and creamy
Putty like
Zinc phosphate cement may be used as a: A. Permanent restoration B. pulp-capping agent C. Sedative restoration D. Thermal insulator under
Thermal insulator under
Access zinc phosphate cement powder left on the mixing slab is:
A. Discarded
B. returned to the bottle
C. Placed under the cement base in the cavity preparation
D. Placed over cement base in the cavity preparation
Discarded
Excess ZOE cement powder left on the mixing slab is:
A. Discarded
B. returned to the bottle
C. Placed under the cement base in the cavity preparation
D. Placed over cement base in the cavity preparation
Returned to the bottle
Why is it a disadvantage if filling materials are radiolucent?
A. Cannot show the Buccal surface
B. can show how deep decay is
C. Will show clearly on radiograph
D. Difficult to differentiate between restoration and recurrent decay
Difficult to differentiate between restoration an recurrent decay
Which would be the restoration of choice for a small cavity on the mesial surface of the maxillary right Central?
A. Amalgam. B. gold inlay
C. Composite. D. Porc jacket
Composite
Which would be the restoration of choice, in most cases, to restore a distal occlusal cavity on the maxillary right first molar?
A. Amalgam. B.gold inlay
C.composite. D. Porc jacket
Amalgam
Which is the restoration of choice for a right maxillary lateral fractured half the way up the crown.
A. Amalgam. B.gold inlay
C. Composite. D.porc jacket
Porcelain jacket
Which is the restoration of choice for a mandibular second molar with the distal buccal cusp missing?
A. Amalgam
B. gold onlay
C. Composite
D. All of the above are of equal quality
Gold onlay
What is the most aesthetic material that can be used in fabricating an anterior bridge?
A. Acrylic B. gold
C. Chrome. D. Porcelain
Porcelain
The chemical used to etch enamel is A. Zinc oxide B. methyl Methacrylate C. Phosphoric acid D. Eugenol
Phosphoric acid
Preventative sealant resins are place on the: A. Occlusal surface B. proximal surface C. Gingival third D. Cusp tips
Occlusal surfaces
The most frequent complaint of patients shortly after amalgam restorations are placed is: A. Pain with percussion B. An open contact point C. Malocclusion D. Numbness around the gingiva
Malocclusion
The polysulfide based materials require mixing together the ----- and the ----- pastes. A.accelerator, catalyst B. catalyst, retardant C.catalyst, base D. Retardant , accelerator
Catalyst, base
If _____ is severe, the pulp is continually irritated, may cause the tooth to remain sensitive following placement of the restoration.
A. Acidity. B. galvanic action
C. Mastication. D. Microleakage
Microleakage
Gutta perchance is used A. As a dental wax B. as imp material for gold posts C. As root canal filling material D. Occl restoration of molars
As a root canal filling material
One disadvantage of a porc jacket is that it A. Is not color stable B. is brittle C. Has low tensile strength D. Is irritating to Gingiva
Is brittle
The ability of material not to become permanently distorted under stress is called.
A.compression B.strain
C.Elasticity. D.Conductibility
Elasticity
“Flow” of a material refers to:
A. Continued change of a material under a given load
B. the consistency of a material when mixing
C. The homogeneity of gypsum material
D. Dimensional change of the material during setting
Continued change of the material under a given load
The stress required to fracture a material by pulling it apart is known as: A. Compressive strength B. ductile strength C. Tensile strength D. Elastic strength
Tensile strength
Which product undergoes an exothermic reaction when setting? A. Amalgam B. zinc oxide-Eugenol C.composite D.plaster
Plaster
The impression material capable of change from gel to sol to gel is: A. Irreversible hydrocolloid B reversible hydrocolloid C. Compound D. Mercaptan
Reversible hydrocolloid
Copper bands are used to carry which impression materials? A. Stick compound B. mercaptan C. Zinc oxide paste D. Irreversible hydrocolloid
Stick compounds
“Force” is:
A. Any push or pull upon matter
B. the distortion or change produced in a body as the result of its internal reaction to an external force
C. The internal reaction to an externally applied force
D. Any push upon matter
Any push or pull upon matter
“Strain” is:
A. Any push upon matter
B. Any push or pull upon matter C.The distortion or change produced in a body has as the result of its internal reaction to an external force the result of stress
D. The Internal reaction to an externally applied force stress
The distortion or change produced in a body as the result of its internal reaction to an external force the results of stress
The characteristic of a liquid to flow easily over a surface is: A. Flow B. wetting C. Viscosity D. Strain
Wetting
A “gel” is
A. A liquid
B. a colloid in which the dispersing medium is water
C. Suspension of particles in some type of dispersing medium
D. Semi solid colloid
Semisolid colloid
Sol is A. Liquid colloid B. solid colloid C. Semisolid colloid D. Suspension of particles in some type of dispersing medium
Liquid colloid
\_\_\_\_\_ is contraindicated for use under resins and composites. A. Calcium hydroxide B. cavity liners C.cavity varnish D.a and c
Cavity varnish
\_\_\_\_is the process by which mercury and alloy are mixed together . A. Amalgamation B. polymerization C. Trituration D. Blending
Trituration
When extruding rubber base impression material, the
A. Base and accelerator are of equal volume
B. base and accelerator are of equal length
C. Amount of each material is not important
D. Base and accelerator are of equal weight
Base and accelerator are of equal length
What is the disadvantage of using compound for making impressions of teeth for prepared crowns
A. It is not accurate
B. the result dies lack sufficient detail
C. Pulpal damage may result
D. The compound may not draw
The compound may not draw
A reason for boxing impressions is: A: to decrease time necessary for trimming models B. easy storage C. Identification D. To increase the hardness of the model
To decrease time necessary for trimming model
Improved stone is used: A.to make dies B. to make study models C.for bite registration D. For articulating models
To make dies
Which cement has the highest compressive strength?
A. ZOE. B. ZOP
C. Polycarboxylate
D. Calcium hydroxide
ZOP
What is the advantage of using zinc polyacrylate ( poly-carboxylate) cement instead of zinc phosphate cement? A. Increased tensile strength B. decreased irritation to pulp C. Increased crushing strength D. Increased compression strength
Decreased irritation to pulp
Which material has the least amount of flow?
A. Acrylic. B. amalgam
C. Cast gold. D. Composite
Cast gold
The process of chemically combining monomer and polymer is
A. Plating. B mesmerizing
C. Bonding. D. Polymerization
Polymerization
Amalgam restorations.
1. Easily inserted. 2 relatively inexpensive.3 have low thermal conductivity 4 are most frequently used in dentistry.
A. 1,2,3. B. 2,3,4. C. 2,4,5 D. 1,2,4
D. 1,2,4
What type of material can be used as a liner under acrylic or composite restorations?
A. Reflect. B. ZOE
C. Vitra-Bond. D. Varnish
Vitra -bond
Tarnish and corrosion of amalgam can be reduced by:
A. Polishing the amalgam
B. using a zinc oxide Eugenol base
C. Using a squeeze cloth to remove excess mercury
D. Undertrituration
Polishing the amalgam
The primary reason for using an individual porcelain jacket is: A. Amount of overjet B. esthetics C. Crushing strength D. Edge strength
Esthetics
Dissimilar metal restorations in the same mouth can cause pain resulting from difference in: A. Cavity preparation B. electrical potential C. Thermal conductivity D. Compressive strengths
Electrical potential
This difference in metal material is called. A. Galvanic shock B. electrical shock C. Gold intolerance D. Metal allergy
Galvanic shock
The oldest impression material is: A. Impression plaster B. irreversible hydrocolloid C. Reversible hydrocolloid D. Silicone impression material
Impression plaster
Which material is thermoplastic?
A. Mercaptan B. alginate
C. Compound. D. Plaster
Compound
One disadvantage of using silicate restoration is: A. It has fluoride in it B. shade is difficult to match C. It is difficult to polish D. It is water soluble
It is water soluble
Resin is changed from its plastic and easily molded shape into a hardened one by a process called A. Polymerization B. adhesion C. Investment D. Thermoplastic
Polymerization
Agar impression materials are examples of ____ hydrocolloids.
A. Reversible. B. irreversible
Reversible
Ductility is the ability of a material to withstand permanent deformation under_____ stress without fracture.
A. Compressive b. tensile
C. Shearing
Tensile
Malleability is the ability of a material to withstand permanent deformation under ____ stress without rupture.
A. Compressive. B. tensile
C. Shearing
Compressive
Durelon is as strong a cement as flecks.
A. True
B. false
False
Amalgamation takes place when \_\_\_\_ is added to an alloy. A. Copper B. mercury C. Tin D. Zinc
Mercury
Polymerization takes place in sealants as a result of A. Heat curing B. light curing C. Self curing D. B and c E. a and e
D . B and c
The property of a liquid that causes it to flow easily is called:
A. Wetting. B. viscosity
C. Adhesion. D. None above
Viscosity
The setting time of gypsum product may be lengthened or shortened by:
A:mixing speed. B. temperature
C. Water/power ratio
D. All above
All above
When mixing gypsum products, if the mix is too thick and more water is needed, the result would be: A. Abnormal mix,decreased strength B. abnormal mix, increased strength C. An exceptionally good mix D. Normal mix
Abnormal mix, decreased strength
Substances are considered “thermoplastic” because of their ability to.
A. Solidify when cooled because of chem changes
B. be softened when heated because of chem changes
C. Be softened when heated and solidify when cooled with chem changes
D. Be softened when heated and solidify when cooled without chem change
Be softened when heated and solidify when cooled without chem changes
A model or replica of a tooth after it has been prepared for an inlay or crown preparation is called a:
A. Pontic B. die
C. Connector D. None above
Die
Specifications and standards for dental materials are set by the: A. Dentist. B. dental pharmacopoeia C. American Dental Association D. Council on dental therapeutics
American dental association
Rubber base (mercaptan) impression material should be mixed in about:
A. One min. B. two mins
C. 30 sec. D. Three min
One minute
The best thing to use to clean ZOP off with is: A. Bleach ( hypochlorite) B. Brillo pad C. Baking soda D. Gluteraldehyde
Baking soda
When mixing zinc phosphate cement, the use of a cool slab is essential because. Give best answer
A. Final mix will be cooler
B. More powder can be incorporated into the mix
C. It allows more control over the work
D. The slab will be easier to clean
More powder can be incorporated into the mix
ZOP should be mixed in approximately one minute
A. True. B. false
False
ZOE should be mixed in approximately one minute
A. True. B. false
True
For best result, the amalgam restoration should be polished: A. Immediately B. at least 12 hrs later C. 24 to 48 hrs later D. At least 48 hrs later
24 to 48 hrs later
Ultimate strength is the point at which stress is too great and the material fractures
A. True. B. false
True
In pouring, stone should be added at one corner of an impression to prevent:
A. Air or water from being trapped on the surface of the cast
B. stone of poor quality from being present on the ridge area
C. Artifacts in the body of the cast
Air or water from being trapped on the surface of the cast
If zinc phosphate cement is mixed to rapidly, it will A. Not affect its setting time B. set faster/ decrease its setting time C. Set slower/ increase its setting time D. Not set
Set fasted/ decrease its setting time
Zinc phosphate cements should be mixed A. Over a small area of the slab B. over a large area of the slab C. As slowly as possible D. As quickly as possible
Over a large area of the slab
What material is used for "pulp-capping?" A. Zinc phosphate B. calcium hydroxide C. ZOE D. Durelon
Calcium hydroxide
During setting, plaster will A. Cool B. expand C. Contract D. Become thermoplastic
Expand
Polishing an acrylic resin denture should:
A. Be done at slow speed to prevent overheating
B. leave a high gloss on all surfaces
C. Be confines to peripheries only
Be done at a slow speed to prevent overheating
What type of materials emit heat heat during a chemical reaction?
a. exothermic B. hygroscopic C. endothermic. D thermoplastics
Exothermic
Why hold a bottle straight up and down when dispensing liquids
A. So it doesn’t drip
B. so it doesn’t change the size of drop
C. So there’s no change in molecular chemistry
D. So you can mi more cement
So it does not change the size of a drop
What does " amalgamate" mean A. Squeeze out excess Mercury B. mull material prior to condensation C. Measure each substance on the scale D. Unite a metal alloy with mercury
Unite a metal alloy with mercury
The laboratory lathe is used primarily to:
A. Trim models. B. polish
C. Reduce wax bulk
D. Sharpen hand cutting instrument
Polish
Any full or partial prosthes fabricated of acrylic should be kept submerged water to:
A. Keep it from picking up odors
B. Prevent distortion
C. Maintain color shades
Prevent distortion
And acrylic appliance store in a sealed plastic bag prior to delivery from a laboratory in order to avoid
A. Discoloration. B. contamination
C. Distortion. D. All above
All above
The ability of a material to withstand permanent deformation, under load without rupture is termed:
A. Tenacity. B. ductility
C. Elasticity. D. Malleability
Malleability
In mixing plaster of Paris, which product is stronger, one with,
A. More water
B. less water
Less water
Increased water in gypsum mix will: A. Prolong setting time B. increase the surface hardness C. Accelerate the setting time reaction D. Increase the compressive strength
Prolong setting time
When a cavity is close to the Pulpal area, the material used to promote formation of secondary dentin is: A. Zinc phosphate B. copalite C. Cavit D. Calcium hydroxide
Calcium hydroxide
Zinc oxide and Eugenol cements are used for: A. Endodontic cementation B. permanent filling C. A base for pulp sensitivity D. Luting permanent restoration
A base for pulp sensitivity
What is the advantage for using glass ionomer cements? A. Long mixing time B. Soothing to pulp C. Easy to manipulate D. Cariostatic
Cariostatic
What is another advantage to using glass ionomer cements? A. Temporary cementation B. slow setting time C. Easy to clean D. Chemical bond to dentin and enamel
Chemical bond to dentin and enamel
The bases of trimmed models (study models) should be --- thick. A. 1/8" B. 1/4" C. 1/2" D. 1"
1/2”
Adding water to a mixture of ZOP will: A. Contaminate the mix B. speed up the final set C. Slow down the final set D. Not alter the final setting time
Speed up the final set
What wax do you use to hold pieces of a broken denture together?
A. Utility. B. inlay
C. Compound. D. Sticky
Sticky
In what order will the asst mix and pass the rubber base material while assisting with an impression for a crown. 1. Load the syringe 2. Mix the heavy body material 3. Mix the light body material 4. Load the custom tray A. 2,1,3,4. B. 3,4,2,1 C. 3,4,1,2. D. 3,1,2,4
D. 3,1,2,4
What material will the dentist place first in amalgam preparation that requires minimal pulpal protection?
A. Amalgam. B. varnish
C. Zinc oxide Eugenol
D. Zinc phosphate
Varnish
The best methods for altering the setting time of irreversible hydrocolloid is to... A. Change the water/ powder ratio B. Change the water temperature C. Change the spatulation time D. Add an accelerator
Change the water temperature
The sequence in which the following medications should be prepared for treatment in the cavity preparation is.… 1. Calcium hydroxide 2. Varnish 3. Zinc phosphate A. 1,2,3. B. 2,1,3. C. 3,1,2. D. 3,2,1
A. 1,2,3
While mixing zinc phosphate for cementation of an onlay, the consistency has become too thick. Which of the following should the dental assistant do? A. Add more liquid B. Leave out some of the powder C. Prepare a new mix D. Decrease spatulation
Prepare a new mix
Which of the following materials is used to stimulate secondary dental formulation? A. Formocresol B. cavity varnish C. Zinc Phosphate D. Calcium hydroxide
Calcium hydroxide
All of the following may be mixed on the paper pad except: A. Calcium hydroxide B. Polycarboxylate cement C. Zinc Phosphate cement D. Zinc oxide eugenol cement
Zinc Phosphate cement
If a reusable capsule with several scratches on the inside is used to triturate amalgam, the new mix may be affected in which of the following ways?
A. It will be unaffected if the scratches are few.
B. it will be contaminated by the previous mix
C. It will have excessive expansion because of the scratches
D. It will have in sufficient expansion because of the scratched
It will be contaminated by the previous mixes
Which of the following types of waxes would be the best choice for use on the periphery of an Alginate impression tray?
A. Baseplate wax B. sticky wax
C. Utility wax. D. Impression wax
Utility wax
Prior to constructing a custom acrylic tray. Wax may be placed over the study cast to…
A. Absorb heat
B. identify anatomical landmark
C. Provide a spacer for the final impression material
D. Conserve acrylic tray material
Provide spacer for the final impression material
In the construction of a custom-made tray, the mixed resin mass should be —-.
A. Sticky. B. doughy
C. Hard. D. Fluid
Doughy
Which of the following statements concerning dentures made out of acrylic type resin is true?
A. They may be cleaned with household scouring powder
B. they may be cleaned with soap and water
C. They should be kept dry if stored for long time
D. They should be stores in a container with hot water
They may be cleaned with soap and water
The mixing time for most plasters and stones is approximately____.
A. 30sec B. 1 min
C. 3 min D. min
1 minute
Broken plastic appliances are temporarily repaired with A. zinc phosphate cement B.sticky wax C.chrome cobalt D. cold cure acrylic
COLD CURE ACRYLIC
For which impression material is it most critial that a model be poured immediatly
- Irriversible hydrochloride material
- . Silicone impression
- .Reversible hydrocolloid material
- Rubber base impression
123
The mixing time for most plasters and stones is approximately____.
A. 30sec B. 1 min
C. 3 min D. min
1 minute
Broken plastic appliances are temporarily repaired with A. zinc phosphate cement B.sticky wax C.chrome cobalt D. cold cure acrylic
COLD CURE ACRYLIC
For which impression material is it most critial that a model be poured immediatly
- Irriversible hydrochloride material
- . Silicone impression
- .Reversible hydrocolloid material
- Rubber base impression
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