Deck 6: Composites, Glass Ionomers, and Compomers

Question 1

If a commercially made radiometer is not available, a rough estimate of curing light output can be made by taking a sample of composite, placing it __________________, and light-curing it on one end for 40 seconds.

A) on the counter after rolling it into a long, thin piece
B) between your forefinger and thumb
C) into a 4-mm length of drinking straw
D) under water

Answer 1

into a 4-mm length of drinking straw

Question 2

Which of the following is a direct-placement esthetic material?

A) Composite resin
B) Silver amalgam
C) Porcelain inlay
D) Full gold crown

Answer 2

Composite resin

Question 3

Flowable composites:

A) are high-viscosity, light-cured resins that may be lightly filled (about 40%) or more heavily filled (up to 70%)
B) are useful as liners in large cavity preparations because they adapt to the preparation better than more viscous materials such as hybrid and packable composites
C) have a high elastic modulus, which allows them to cushion stresses created by polymerization shrinkage or heavy occlusal loads
D) are useful for class I but not class V restorations

Answer 3

are useful as liners in large cavity preparations because they adapt to the preparation better than more viscous materials such as hybrid and packable composites

Question 4

The catalyst paste of a chemically cured composite resin contains __________ as an activator.

A) benzoyl peroxide
B) a tertiary amine
C) camphoroquinone
D) dimethacrylate

Question 5

Composite resins are composed mainly of an organic resin matrix and inorganic silica filler particles joined together by a _______ coupling agent.

A) colloidal
B) surfactant
C) silane
D) hydrophobic

Question 6

In the polymerization process for composite resins, an activator causes an initiator molecule to form a _________ that breaks one of the carbon-to-carbon double bonds to form a single bond and another free radical.

A) eutectic
B) ( $\gamma$ -phase)
C) free radical
D) ketone

Question 7

The fillers used in composite resins are:

A) bis-GMA
B) urethane dimethacrylate (UDMA)
C) inorganic silica particles
D) a low molecular weight monomer called TEGDMA

Question 8

What type of restorative material is used for the atraumatic restorative treatment (ART) of caries?

A) High-viscosity glass ionomer composite
B) Hybrid (resin-modified) ionomers
C) Compomers
D) Conventional composite resins

Question 9

Which of the following types of curing lights is currently the most popular?

A) Halogen (quartz-tungsten-halogen, or QTH)
B) Plasma arc (PAC)
C) Laser (initially argon laser)
D) Light-emitting diode (LED)

Question 10

Nanohybrids have a particle size of ________ microns ( $\mu$ m).

A) 10 to 100
B) 0.03 to 0.5
C) 0.1 to 3
D) 0.005 to 0.020

Question 11

In general, it is recommended that light-cured composite be placed in increments no thicker than __ mm.

A) 0.5
B) 2.0
C) 4.0
D) 8.0

Question 12

Which part of the tooth is generally closest to the dentin in color?

A) Cervical
B) Body
C) Occlusal area of posterior teeth
D) Incisal area of anterior teeth

Question 13

Which of the following is true of nanohybrid composite resins?

A) With more resin than previous generations, these composites shrink less when polymerized.
B) The shrinkage has been reduced from roughly 3% with earlier composites to less than 1% with some of the nanohybrids.
C) These are weak composites.
D) These composites cannot be polished to a high shine.

Question 14

It is recommended to ______________ to reduce sticking of the composite material to the placement instrument.

A) wet the composite instrument with alcohol
B) use a little of the bonding agent
C) use a little of an unfilled resin
D) place the composite material in the refrigerator

Question 15

Which of the following chemicals is used to prepare the dentinal tooth surface for placement of glass ionomer cement?

A) 35% phosphoric acid
B) 10% polyacrylic acid
C) A rotary cutting instrument such as a diamond bur
D) Nothing; it bonds to calcium without surface preparation

Question 16

Glass ionomers can be used as:

A) restorations
B) cements
C) sealants
D) All of the above

Question 17

Which of the following is true concerning polymerization shrinkage of composite resin restorations?

A) Recent research indicates that the composite resin material does not shrink toward the light.
B) When composite is placed and cured in a preparation that has two opposing walls, the composite will expand and push against the walls.
C) The greater the resin content of the composite, the less will be the shrinkage.
D) Microfills and flowables shrink less than hybrids and packables.

Question 18

Packable composites are used for restoration of:

A) anterior teeth in areas of high function
B) anterior teeth in areas of low function
C) posterior teeth in areas of high function
D) posterior teeth in areas of low function

Question 19

During incremental addition of composite resin, each additional increment will bond to the previously placed increment of composite:

A) if etchant is used between layers
B) if etchant and primer are used between layers
C) if etchant, primer, and bond agent are used between layers
D) as long as good isolation is maintained and no contaminants are introduced

Question 20

For composite restorative materials, the greater the filler content, the _____ the coefficient of thermal expansion (CTE), and the greater the resin content, the _______ the CTE.

A) greater; greater
B) greater; lower
C) lower; greater
D) lower; lower

Question 21

Composite resins should be placed in:

A) Large increments to avoid shrinkage
B) Small increments to avoid shrinkage
C) The material doesn't shrink.

Question 22

Match the items with the correct description below.

-Hybrid composite

A)A light-cured, low-viscosity composite resin that contains fewer filler particles
B)An early generation of composite that contained filler particles ranging from 10 to 100 $\mu$ m in diameter
C)A light-cured, highly viscous, heavily filled composite resin for dentists who use a placement technique with composite that is similar to amalgam
D)Composite that contains both macrofill and microfill particles
E)Composite that contains very small filler particles averaging 0.04 $\mu$ m in diameter

Question 23

Match the items with the correct description below.

-Flowable composite

A)A light-cured, low-viscosity composite resin that contains fewer filler particles
B)An early generation of composite that contained filler particles ranging from 10 to 100 $\mu$ m in diameter
C)A light-cured, highly viscous, heavily filled composite resin for dentists who use a placement technique with composite that is similar to amalgam
D)Composite that contains both macrofill and microfill particles
E)Composite that contains very small filler particles averaging 0.04 $\mu$ m in diameter

Question 24

Curing time for a curing light with a halogen bulb should be:

A) 10 to 15 seconds
B) 15 to 30 seconds
C) 20 to 40 seconds
D) per manufacturer's instructions

Question 25

Color is matched to the patients existing tooth structure by:

A) using a shade guide
B) moistening the teeth
C) curing a small amount
D) All are good choices.

Question 26

Match the items with the correct description below.

-Microfilled composite

A)A light-cured, low-viscosity composite resin that contains fewer filler particles
B)An early generation of composite that contained filler particles ranging from 10 to 100 $\mu$ m in diameter
C)A light-cured, highly viscous, heavily filled composite resin for dentists who use a placement technique with composite that is similar to amalgam
D)Composite that contains both macrofill and microfill particles
E)Composite that contains very small filler particles averaging 0.04 $\mu$ m in diameter

Question 27

Match the items with the correct description below.

-Macrofilled composite

A)A light-cured, low-viscosity composite resin that contains fewer filler particles
B)An early generation of composite that contained filler particles ranging from 10 to 100 $\mu$ m in diameter
C)A light-cured, highly viscous, heavily filled composite resin for dentists who use a placement technique with composite that is similar to amalgam
D)Composite that contains both macrofill and microfill particles
E)Composite that contains very small filler particles averaging 0.04 $\mu$ m in diameter

Question 28

Match the items with the correct description below.

-Packable composite

A)A light-cured, low-viscosity composite resin that contains fewer filler particles
B)An early generation of composite that contained filler particles ranging from 10 to 100 $\mu$ m in diameter
C)A light-cured, highly viscous, heavily filled composite resin for dentists who use a placement technique with composite that is similar to amalgam
D)Composite that contains both macrofill and microfill particles
E)Composite that contains very small filler particles averaging 0.04 $\mu$ m in diameter

Question 29

List the advantages and disadvantages of composite resins.

Question 30

Some composite resin materials give off heat when cured. This is called a/an:

A) chemical reaction
B) thermal conductivity
C) exothermic reaction
D) None of the above

Question 31

The use of two different restorative materials in the same restoration is referred to as the:

A) hybrid technique
B) sandwich technique
C) layered technique
D) veneer technique

Question 32

Which of the following composite resin materials would not be used in non-stress-bearing areas?

A) Macrofilled
B) Microfilled
C) Microhybrid

Question 33

The organic matrix of composite resins is made up of:

A) bis-GMA
B) glass
C) silica
D) quartz

Question 34

Which of the following materials is fluoride releasing?

A) Porcelain
B) Glass ionomer
C) Composite resin

Question 35

List the three different types of composite resins and describe how they each polymerize.