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