Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

F16: Dental Materials > Intro to Biomaterials > Flashcards

Intro to Biomaterials Flashcards

1
Q

What are the three main classes of materials?

A
  1. Polymers
  2. Ceramics
  3. Metals
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

_________ have the properties of being strong, ductile, and hard.

A

Metals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

_________ have the properties of being hard, brittle, and strong.

A

Ceramics

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

________ have the properties of being soft, ductile, and weak.

A

Polymers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Which material has the lowest processing temperature?

A

Polymers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Which material is used as a direct processing material?

A

Polymers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are metal alloys and what properties are associated with them.

A

Mixture of two or more metals.

Stronger and less ductile

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

How are metals bonded?

A

Metallic bonds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Describe the process as metal goes from molten to cool.

A

Single atoms -> crystal growth -> formation of grains (polycrystalline structures)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What type of bonds are associated with ceramics?

A

Ionic and covalent bonds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

T/F: Metallic bonds are stronger than both ionic and covalent bonds.

A

FALSE.

Both ionic and covalent are stronger than metallic bonds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Which is a stronger bond, covalent or ionic?

A

Covalent

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

T/F: Ceramics involve only non-metallic elements.

A

FALSE.

Both metallic and non-metallic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the building block of most ceramics?

A

SiO4

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

T/F: Crystalline microstructure of ceramics is involved with long range order.

A

TRUE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

T/F: Noncrystalline ceramic microstructure is involved with long range order.

A

FALSE

Short range order

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What type of microstructure do most dental ceramics have?

A

Semicrystalline or polycrystalline

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

How is porcelain processed?

A

Sintering or melting at high temperatures

19
Q

T/F: Polymers form ionic bonds.

A

FALSE

Covalent bonds!

20
Q

Do polymers have a low or high molecular weight?

A

HIGH

21
Q

T/F: Polymers contain mostly nonmetallic elements.

A

TRUE

22
Q

How do polymers get their strength and properties?

A

The entanglement of a long chain of covalent bonds.

23
Q

What are the steps in the polymerization process?

A
  1. Activation: free radical initiation
  2. Initiation: free radical combines with monomer opening
  3. Propagation: chain growth, volume decrease, shrinkage
  4. Termination
24
Q

What are the three ways polymerization can be initiated?

A
  1. Light
  2. Heat
  3. Chemical mixing
25
Q

T/F: Polymerization reactions are fast and may generate a lot of heat.

A

TRUE

26
Q

What is the importance of polymerization in dentistry?

A

Allows for direct placement of a flowable material, followed by rapid processing into a stable material

27
Q

What is the major metal that allows for direct processing?

A

Amalgam

28
Q

What ceramic allows for direct processing?

A

Cements

29
Q

T/F: Temporary crowns are made from cross linked polymers.

A

FALSE.

Linear

30
Q

T/F: Adhesives and restoratives are made from crosslinked polymers.

A

TRUE

31
Q

What is a composite?

A

Physical mixture of metals, ceramics, and polymers.

32
Q

What is the rule of mixtures?

A

By understanding the phases present in the structure of a material and its interactions, properties can be predicted

33
Q

How much filler is typically found in a composite and what are common filler types?

A

75-80 wt%

Silicate glass (1-100 um)
Colloidal silica (.05 um)
34
Q

If I wanted a composite with a very fine surface would I want one with silicate glass or colloidal silica?

A

Colloidal silica because it is smaller

35
Q

What happens as a composite has an increased filler volume.

A

Strength, modulus, and viscosity all INCREASE

Shrinkage DECREASES

36
Q

What is the specific gravity of a material?

A

Density of the material/density of water

37
Q

T/F: Most things expand when heated, and contract when cooled.

A

TRUE

38
Q

List the three major dental materials in order from least to greatest potential for thermal expansion.

A

Ceramics (1-15)
Metals (10-30)
Polymers (30-600)

39
Q

What is the coefficient of thermal expansion for teeth? Amalgam? Composite?

A 
Tooth = 9-11
Amalgam = 25
Composite = 28-35
40
Q

Why do metals need an insulator such as base?

A

They have a high thermal conductivity and the pulp cannot withstand large temperature changes for long periods of time.

41
Q

T/F: Composites have low thermal conductivity so they do not need base.

A

TRUE

42
Q

Color is defined in a _______ _________ coordinate system.

A

Three dimensional

43
Q

What are the three dimensions of color?

A

Hue: wavelength, color

Value: intensity, brightness

Chroma: purity, concentration

44
Q

What is metamerism?

A

When two objects appear the same color under one light source and different under another light source

F16: Dental Materials (5 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions