Dental materials - last test
_______ are the most accurate, stable, and expensive impression materials. they are also called vinyl polysiloxanes and polyvinylsiloxanes
addition ilicones
latex gloves should not be worn when mixing ______.
addition silicones
which of the following impression materials set by physical means?
agar
which of the following materials may release fluoride?
all of the above
a _______ provides thermal insulation.
base
T/F hybrid ionomers release more fluoride than compomers or composites, but less than glass ionomers.
both parts of the statement are true.
T/F agar is a reversible hydrocolloid. reversible hydrocolloid is premixed by the manufacturer and supplied as a semisolid material in tubes and sticks.
both statements are true.
what is the most appropriate base material for a deep cavity prep?
calcium hydroxide
which of the following dental materials promotes the formation of secondary dentin?
calcium hydroxide
glass ionomer is the material of choice for what class of restoration?
class V
all of the following fillers are radiopaque except:
colloidal silica
varnish is not used with ______ materials because it would interfere with adhesion.
composite
______ shade require longer exposure.
darker
larger particles ______ the surface smoothness.
decrease
a ______ is a material that is placed on vital pulp tissue when the overlying dentin is removed and the pulp is exposed.
direct pulp cap
______ is a major component of oil of cloves.
eugenol
what are the three liquids used in dental cements?
eugenol, phosphoric acid, polyacrylic acid
all of the following are characteristics of zinc oxide eugenol except:
fluoride release
the root canal filling material, ________, is solid at room temperature and becomes soft and liable when heated.
gutta-percha
the fluoride content of ______ can be recharged with the of fluoride treatment or fluoride toothpaste.
hybrid ionomers
characteristics of a higher powder/liquid ratio includes all of the following except:
increased setting time
as the filler content _______, hardness and abrasion resistance increases and polymerization shrinkage decreases.
increases
the esthetics of glass ionomer materials are ______ to those of dental composites.
inferior
what is the least accurate impression material?
irreversible (alginate)
one of the principal advantages of zin polycarboxylate cement over zinc phosphate cement is:
its minimal pulpal irritation
retention of zinc phosphate cement is caused by ______ with the tooth and restoration.
mechanical interlocking
what are the types of dental composites based on filler content?
microfilled, macofilled, hybrid
the reaction of a reversible hydrocolloid is described as _____.
physical
all of the following are nonaqueous elastomeric impression materials except one. which one is the exception?
plaster
______ impression materials have a disagreeable smell and taste. they stain clothing and are generally regarded as unpleasant materials.
polysulfide
zinc oxide eugenol is ______ impression material.
rigid
zinc oxide eugenol cement is used for _____ fillings.
sedative
which of the following is a base that is placed over a pulp that has been damaged by decay or has been irritated during the process of removing the decay
sedative base
for _____, the material is mixed to a thicker consistency than is used for luting.
temporary restorations
if a luting mix becomes _____, the restoration may not seat adequately. in this case, the marginal gap is increased, as is the likelihood of caries.
too thick
_______ functions as a chemical barrier and is frequently used to seal preparations for amalgam restorations.
varnish
advantages of glass ionomer materials include all of the following EXCEPT:
wear resistant esthetically pleasing
what are the two materials used to make powders for dental cements?
zinc oxide and glass
what is the composition of zinc phosphate cement?
zinc oxide and phosphoric acid
what is the composition of zinc polycarboxylate cement?
zinc oxide and polyacrylic acid
_______ can not be used with composites.
zinc oxide eugenol
which of the following has an obtundent effect on the pulp?
zinc oxide eugenol
which of the following is not used for final cementation?
zinc oxide eugenol type 1
which of the following is not a direct esthetic material?
zinc phosphate
the setting time of zinc phosphate cement is increased by:
- cooling the glass mixing slab - adding the powder in small increments and mixing within 60 seconds
100% gold is ______ carat
24
_______ the most common matrix of a dental composite (resin).
Bis-GMA
______ has excellent resistance to corrosion and good malleability.
Gold
_______ is the removal of excess amalgam from margins.
Margination
what alloys are used for construction of partial denture framework?
Nickel-chromium and cobalt-chromium
The use of bonding in dentistry serves all of the following functions EXCEPT:
Retention of color in the restoration
