Dental Materials Exam

Question 1

What are the 3 main classes of dental materials?

Answer 1

1. Metals
2. Ceramics
3. Polymers

Question 2

What are the 3 mechanical properties of metals?

Answer 2

1. Hard
2. Ductile - Tough
3. Strong

Question 3

What are the 3 mechanical properties of ceramics?

Answer 3

1. Hard
2. Brittle
3. Strong

Question 4

What are the 3 mechanical properties of polymers?

Answer 4

1. Soft
2. Ductile - Tough
3. Weak

Question 5

Which materials have a high processing temperature?

Answer 5

Metals and Ceramics

Question 6

What material has a lower processing temperature?

Answer 6

Polymers

Question 7

Which material is used as a direct processing material?

Answer 7

Polymers

Question 8

What 4 dental examples were given for the use of metals?

Answer 8

1. Cast crowns
2. Implants
3. Posts & Core
4. Metal-ceramic crowns

Question 9

What type of bonding do metals use?

Answer 9

Metallic

Question 10

Because of electrons having free mobility thermal and electrical conductivity is higher or lower?

Answer 10

Higher

Question 11

List 2 ceramic dental examples given in class.

Answer 11

1. All ceramic crowns

2. Metal-ceramic crowns

Question 12

What type of bonding do ceramics use?

Answer 12

Ionic and covalent

Question 13

Place in order of strength. Metallic, Ionic, Covalent bonding

Answer 13

Covalent > Ionic > Metallic

Question 14

How are polymers processed?

Answer 14

By melting at high temperatures

Question 15

What type of bonding do polymers use?

Answer 15

Covalent bonds

Question 16

How do polymers derive strength?

Answer 16

From their entanglement

Question 17

What are the 4 steps of the polymerization process?

Answer 17

1. Light activation
2. Initiation of monomer
3. Propagation of free radical
4. Termination of free radical

Question 18

Liquid monomers and solid polymers are found in which dental material?

Answer 18

Polymers

Question 19

Initiators will typically do what to the monomer they act on?

Answer 19

Create a free radical

Question 20

Which stage does the free radical continues by building of polymers by different monomers.

Answer 20

Propagation

Question 21

During propagation does volume increase or decrease?

Answer 21

Decrease

Question 22

During propagation do the molecules grow or shrink?

Answer 22

Shrink

Question 23

During which stage are the free-radicals capped no longer active to work on other monomers?

Answer 23

Termination

Question 24

There can be two types of chains created, what are they?

Answer 24

1. Linear chains

2. Branched and cross linked chains

Question 25

What is one characteristic of cross linked chains?

Answer 25

Stronger

Question 26

Which materials use direct or indirect processing? Metals, ceramics, and polymers

Answer 26

Metals - indirect
Ceramics - indirect
Polymers - direct

Question 27

What is the exception for metals being placed indirectly?

Answer 27

Amalgams - placed directly

Question 28

What is the exception for ceramics being placed indirectly?

Answer 28

Cements - placed directly

Question 29

What is the exception for polymers being placed directly?

Answer 29

Indirect composites - placed indirectly

Question 30

When would we use linear polymers in dentistry?

Answer 30

Temporary crowns

Question 31

When would we use cross linked polymers in dentistry?

Answer 31

Adhesives - Restoratives

Question 32

What type of material is impression alginate?

Answer 32

Polymer

Question 33

What is a material that has been mixed with metals, ceramics, and/or polymers called?

Answer 33

Ceramics