Introduction to Composites

Question 1

This was used to restore caries in anterior teeth in 1878; it released fluoride but was very soluble and became rough fast

Answer 1

Silicate Cement

Question 2

This was, because of its weakness, was used as esthetic veneer on facial surfaces of class II and IV metal restorations in the 1930s

Answer 2

acrylic resin

Question 3

What were some issues with acrylic resin in the 1930s

Answer 3

high polymerization shrinkage
high coefficient of thermal expansion
lack of wear resistance
recurrent caries
color change

Question 4

What is the composition of composite resin in the 1960s

Answer 4

polymer (resin matrix) + inorganic filler particles

Question 5

What properties do the inorganic filler particles give to the composite resin in the 1960s

Answer 5

increase strength

decrease thermal expansion

Question 6

This was added to composite resin to cover the filler particles, gluing the particle to the resin; fillers no longer falling out of the composite

Answer 6

coupling agent

Question 7

How are composites classified, and which ones do we use

Answer 7

according to filler size, amount, and composition

we use nano-filler

Question 8

What are the three classifications of composite

Answer 8

flowable
packable
universal

Question 9

This is needed regarding composites

Answer 9

a bonding agent

Question 10

What happens when a composite undergoes polymerization

Answer 10

shrinkage

Question 11

This determines the stress on a restoration; the number of bonded walls to unbounded walls; the high the number the more stress applied

Answer 11

C factor

Question 12

Which classification of composite restorations have the highest and lowest C factor

Answer 12

Class I = highest

Class V and IV = lowest

Question 13

Internal stresses in high C-factor configurations can be reduced by what three things

Answer 13

soft-start polymerization instead of high intensity light
incremental addition of material
use of stress breaking liner

Question 14

What are two methods of composite polymerization

Answer 14

self-cured

light-cured

Question 15

What are the differences between amalgam and composite in terms of retention

Answer 15

amalgam; must be mechanically locked inside the tooth

composite; held in place by micro-mechanical retention of the bonding agent

Question 16

What are six advantages of using composites

Answer 16

esthetics
conserves tooth structures
easier, less complex, tooth preparation
insulation
bonds to tooth structure, increases strength of remaining tooth structure
repairable

Question 17

What are five disadvantages of using composites

Answer 17

gap forming at margins
more technique sensitive to achieve good results
more difficult and time consuming to place
may exhibit occlusal wear (more than amalgam)
lower fracture toughness than most indirect restorations

Question 18

What is a contraindication of using composites

Answer 18

operating field that can not be adequately isolated

Question 19

What are the 5 steps to restoring with composite

Answer 19

rubber dam isolation
remove caries/defect
remove unsupported tooth structure
prepare margins
restore

Question 20

How long do composites last

Answer 20

anterior composites have been shown to last about 30 years

Question 21

What three things does the success of any restoration depend upon

Answer 21

operator
patient
material

Question 22

What three things must the operator do properly to ensure success of the restoration

Answer 22

proper isolation
proper handling of the material
proper bonding

Question 23

What four things regarding the patient does the success of the restoration depend upon

Answer 23

nature and extend of caries or defect
occlusion
caries risk
parafunctional occlusal habits