Dental Materials Ch. 5

Question 1

one problem with polymers is their high coefficient of thermal expansion. These coefficients can be ___to___times greater than that of tooth structure.

(a) 1 to 3
(b) 3 to 5
(c) 2 to 5
(d) 2 to 10

Answer 1

(d) 2 to 10

Question 2

Which of the following components of restorative resins acts as a “coating” and serves to transfer stress from a weak component to a stronger one?

(a) Matrix
(b) Filler particle
(c) Silane coupling agent
(d) Polymers
(e) Adhesives

Answer 2

(c) Silane coupling agent

Question 3

What advantage do microfilled composities have compared to macrofilled composties?

(a) Low coefficient of thermal expansion
(b) Smooth and lustrous polished surface
(c) Greater overall strength
(d) Higher percentage of filler

Answer 3

(b) Smooth and lustrous polished surface

Question 4

Which of the following characteristics best describes chem-
ical-cure composite restorative materials?

(a) Unlimited working time
(b) Supplied as single paste materials
(c) May incorporate air bubbles during mixing
(d) Contains less matrix and more fi ller particles

Answer 4

(c) May incorporate air bubbles during mixing

Question 5

A specific amount of composite (thickness) that is cured by a light source is termed

(a) Depth of cure
(b) Incremental addition
(c) Depth of addition
(d) Incremental polymerization

Answer 5

(a) Depth of cure

Question 6

The size of the filler particles in a dental composite determines the

(a) Polymerization reaction
(b) Technique for incremental additions
(c) Etching time before the primer and adhesive are placed
(d) Surface smoothness of the resulting restoration

Answer 6

(d) Surface smoothness of the resulting restoration

Question 7

The __________ composite restorative materials are those with a lower viscosity (decreased filler) to aid in placement.

(a) Preventive resin
(b) Hybrid
(c) Flowable
(d) Condensable

Answer 7

(c) Flowable

Question 8

hybrid composites are recommended for

(a) Surface luster
(b) Areas needing strength
(c) Low-stress areas
(d) Class V restorations

Answer 8

(b) Areas needing strength

Question 9

a combination of a pit and fissure sealant and a composite restoration is termed

(a) Flowable composite
(b) Condensable composite
(c) Compomer
(d) Preventive resin restoration

Answer 9

(d) Preventive resin restoration

Question 10

abrasion resistance for hybrid composite restorative material is said to be

(a) Poor
(b) Fair
(c) Good
(d) Very good

Answer 10

(d) Very good

Question 11

thermal expansion for microfill composite restorative material is considered to be

(a) Poor
(b) Fair
(c) Good
(d) Very good.

Answer 11

(a) Poor

Question 12

which composite material has the largest percentage of filler by weight

(a) Microfill
(b) Hybrid
(c) Macrofill
(d) Flowable

Answer 12

(b) Hybrid

Question 13

composite materials that polymerize using light activation are

(a) Initiated by mixing
(b) Not as popular as chemically activated resins
(c) Supplied as a single paste
(d) Lack the “set on demand” characteristic

Answer 13

(c) Supplied as a single paste

Question 14

a restorative material that initially releases some fluoride like glass ionomers and sets like composites is called

(a) Flowable composites
(b) Condensable composite
(c) Compomer
(d) Preventive resin restoration

Answer 14

(c) Compomer

Question 15

which of the following best describes microfill composite materials?

(a) Abrasion resistance is poor; fi ller size is 10-25 microns
(b) Abrasion resistance is poor; strength is high
(c) Polishability is poor; strength is high
(d) Polishability is very good; strength is low

Answer 15

(d) Polishability is very good; strength is low