Introduction to Restorative Dentistry

Question 1

Define metals

Answer 1

Elements that share valence electrons among all the atoms in the solid

Question 2

Define metal alloy

Answer 2

Any intentional mixture of metallic elements
- Mixture of metal so it’s better for mouth

Question 3

Define ceramics

Answer 3

Chemically intimate mixtures of metallic and non-metallic elements which allow covalent or ionic bonding

Question 4

Examples of ceramics

Answer 4

Dental porcelains & refractories

Question 5

What are the categories of dental materials?

Answer 5

Metals
Metal alloy
Ceramics
Polymers
Composites

Question 6

Define polymers

Answer 6

Long molecules composed primarily of non-metallic elements that are bonded covalently

Question 7

Examples of polymers

Answer 7

Acrylics, waxes, & cements

Question 8

Define composites

Answer 8

Physical mixtures (blends) of metals, ceramics, or polymers to use the desired properties of each

Question 9

Resins, ionomers, compomers, bonding agents, and cements are examples of

Answer 9

Composites

Question 10

___ is the controlling factor in bond formation

Answer 10

Energy

Question 11

When 2 atoms come together, they may link to form a molecule. This is ___ bond

Answer 11

Primary

Question 12

Bonds form only if it results in

Answer 12

A lowering of the total energy of the atoms being joined

Question 13

Define covalent bonds

Answer 13

• Strongest and simplest
• Atoms share electrons
• Highly directional bonds

Question 14

Define ionic bonds

Answer 14

• 1 atom gives up an electron to another atom
• Atom that gives up electron becomes + while the atom that accepts the electron becomes -
• Nondirectional
• Attract each other & reduction in total energy

Question 15

___ bonds occurs where there is a large group of atoms, usually in a solid, that will readily give up valence electrons

Answer 15

Metallic

Question 16

What types of bonds are non-direcitonal?

Answer 16

Ionice and metallic

Question 17

Define bond energy

Answer 17

Amount of energy that has to be supplied to separate 2 atoms

Question 18

Which type of bond has the highest and lowest bond energy?

Answer 18

Highest = covalent
Lowest = metallic

Question 19

Ionic solids are beneficial and ___ the energy

Answer 19

Lowers

Question 20

Metallic solids have ___ electrostatic attraction between atoms

Answer 20

No strong

Question 21

Metallic solids are held together by

Answer 21

Cloud of electrons

Question 22

Covalent solids have ___ bonds that ___ the possible arrangement of atoms

Answer 22

Directional
Limit

Question 23

Define secondary bonds

Answer 23

When electrons are shared, they may spend a disproportionate time in 1 particular position
- one end of molecule will be + and the other -

Question 24

Define molecular solids

Answer 24

• Molecules solid at room temp
• If they’re long enough the dipole-dipole interactions can bond molecules together

Question 25

What are examples of secondary bonds?

Answer 25

- Molecular solids - Solid arrangements

Question 26

What are examples of primary bonds?

Answer 26

- Ionic solids - Metallic solids - Covalent solids

Question 27

___ are crystalline atoms arranged in symmetrical pattern

Answer 27

Solid arrangements

Question 28

Amorphous has ___ symmetrical arrangement of atoms

Answer 28

No

Question 29

What are the properties of materials

Answer 29

- Physical - Mechanical - Chemical - Biological - Electrical - Surface Properties - Surface energy - Wettability - Adsorption - Absorption

Question 30

Describe physical properties

Answer 30

Reversible interactions of a material w/ its environment

Question 31

Describe mechanical properties

Answer 31

A response to loading stress-strain - Strength of material in response to having a load on it

Question 32

What are the 3 atomic building blocks?

Answer 32

Ceramics, metals, and polymers

Question 33

Changes in primary and secondary bonding is what type of property?

Answer 33

Chemical

Question 34

Toxity and sensitivity reactions that occur locally or systemically within associated tissues is what type of material?

Answer 34

Biological

Question 35

Describe electrical properties of materials

Answer 35

Galvanism The generation of electrical currents by dissimilar metals

Question 36

A low surface energy liquid will readily spread over a high surface energy substrate is what property of material?

Answer 36

Surface energy

Question 37

Define wettability

Answer 37

Measure of the affinity of a liquid for a solid as indicated by the spreading of a drop

Question 38

___ is the angle between the liquid surface and the solid surface depends on surface energies

Answer 38

Contact angle

Question 39

What is the perfect wettability contact angle?

Answer 39

0

Question 40

Define adsorption

Answer 40

- Dissimilar substances in intimate contact w/ the surfaces of a solid stick together - Appears on surface - High energy surfaces will absorb molecules more readily

Question 41

Define absorption

Answer 41

- Uptake of a liquid by a bulk solid - Substance absorbed diffuses into solid material

Question 42

___ is the ability of a material to elicit an appropriate response in a given application in the body

Answer 42

Biocompatibility

Question 43

In a ___ test, material is placed in a situation identical to its intended clinical use

Answer 43

Usage test

Question 44

Advantages & disadvantages of in vitro tests

Answer 44

Advantages - quick - least expensive - can be standardized - good control - large scale screening Disadvantage - Relevance is quiestionable

Question 45

Advantages & disadvantages of in vivo tests

Answer 45

Advantages - Allows complex systemic interactions - Response more comprehensive than in vitro tests - More relevant than in vitro tests Disadvantages - Relevance is questionable - Expensive - Time consuming - Legal/ethical concerns - Difficult to control - Difficult to interpret & quantify

Question 46

Advantages & disadvantages of usage tests

Answer 46

Advantages - Relevance to use of material is assured Disadvantages - Very expensive - Time consuming - Legal/ethical issues - Difficult to control - Difficult to interpret & quantify