Ch 43

Question 1

Restorative

Answer 1

the ability to remove decay or disease and bring proper function back to the tooth

Question 2

Esthetic

Answer 2

the recreating the tooth or teeth with an artistically pleasing appearance

Question 3

Criteria for a new dental material

Answer 3

It must not be poisonous or harmful to the body

It must not be harmful or irritating to the tissues of the oral cavity

Question 4

criteria for new dental material

Answer 4

It must help protect the tooth and oral tissues of the oral cavity

It must resemble the natural dentition as closely as possible so as to be esthetically pleasing.

Question 5

criteria for new dental material

Answer 5

It must be easily formed and placed in the mouth

It must conform to function

Question 6

The Council on Dental Materials, Instruments and Equipment, a subcommittee of the American Dental Association,

Answer 6

works with federal agencies to ensure that strict specifications are followed by manufacturers in the development of new dental materials.

Question 7

The following characteristics enhance the ability of dental materials to withstand the oral environment and allow for easy application….

Answer 7

Mechanical properties

Thermal changes

Electrical properties

Corrosive properties

Solubility

Application properties

Question 8

electrical and corrosive properties are…

Answer 8

important with metallic restorations

Question 9

thermal insulation is desirable for example…

Answer 9

under an extensive restoration and under a denture base we would like thermal transfer.

Question 10

mechanical properties

Answer 10

Materials must be able to withstand the biting and chewing force in the posterior area of the mouth.

Question 11

force

Answer 11

any push or pull on matter

Question 12

stress

Answer 12

the reaction within the material that can cause distortion

Question 13

strain

Answer 13

the change produced within the material that occurs as the result of stress

Question 14

A restoration will eventually reach a breaking point…

Answer 14

causing permanent deformation (change) after a certain amount of both stress and strain is applied over a certain amount of time.

Question 15

Mechanical properties of a material placed in the anterior area should also withstand various forces caused by factors,

Answer 15

including occlusion and a patient’s habits.

Question 16

Remember that different materials have different properties

Answer 16

under different types of force

Question 17

tensile stress

Answer 17

pull and stretches the material

Question 18

compressive stress

Answer 18

pushes the material together

Question 19

shear stress

Answer 19

breakdown of the material as the result of something sliding over 2 areas

Question 20

a patient enjoys eating sticky candy

Answer 20

tensile stress

Question 21

a patient reports clenching his teeth when he is concentrating hard at work

Answer 21

compressive stress

Question 22

a patient has a habit of grinding her teeth at night or nocturnal bruxism

Answer 22

shear stress

Question 23

ductility

Answer 23

the measure of the capacity of a metal to be stretched or drawn by pulling or tensile force w/o fracturing

Question 24

malleability

Answer 24

the measure of the capacity of a metal to be extended in all directions by a compressive force, such as rolling or hammering

Question 25

thermal changes

Answer 25

A change in temperature in the oral cavity resulting from a hot or cold product.

Question 26

These thermal changes are of major concern because of

Answer 26

Contraction and expansion | The need to protect the pulp from thermal shock from extreme differences in temperature

Question 27

When the restorative material and surrounding tooth structure have different rates of contraction and expansion, ______ may occur

Answer 27

microleakage

Question 28

Space between the tooth and the restoration allows _____or_______ to enter, causing sensitivity and/or breakdown of that interface and ultimately destroying the restoration and permitting decay in the tooth.

Answer 28

saliva or bacteria

Question 29

Space between the tooth and the restoration allows saliva or bacteria to enter, causing _________ of that interface and ultimately destroying the restoration and permitting decay in the tooth.

Answer 29

sensitivity and/or breakdown

Question 30

Space between the tooth and the restoration allows saliva or bacteria to enter, causing sensitivity and/or breakdown of that interface and ________________

Answer 30

ultimately destroying the restoration and permitting decay in the tooth.

Question 31

what does galvanic shock feel like ?

Answer 31

an undesirable tingling sensation

Question 32

Conditions that allow these electrical currents include:

Answer 32

Saliva contains salt, a good conductor Two metallic components of different composition can act as a battery Galvanic action, or shock,

Question 33

Galvanic action, or shock...

Answer 33

is the coming together of all these conditions

Question 34

An electrical current, or galvanic action, in the oral cavity can take place ....

Answer 34

when there are two different or dissimilar metals present.

Question 35

One patient who may report such a feeling is someone who has teeth on opposing arches that contact each other in function....

Answer 35

The teeth contain restorations composed of different metals (e.g., a full gold crown opposing a large amalgam).

Question 36

Corrosive properties

Answer 36

The reaction of metals that occurs within a metal when it is exposed to corrosive products such as temperature, humidity and saline

Question 37

Most corrosion involves surface discoloration and can be removed easily with the use of

Answer 37

polishing agents

Question 38

What common drinks or foods have corrosive properties?

Answer 38

Soft drinks, concentrated lemonade, and other products that create a highly acidic oral environment.)

Question 39

Plaque that remains for an extended period on the margin between an amalgam and the tooth may also produce...

Answer 39

a more acidic environment locally

Question 40

An acidic environment (lactic acid under dental plaque)

Answer 40

drastically changes the solubility of tooth structure, such as enamel.

Question 41

Because enamel is the hardest substance in the body,

Answer 41

the plaque must have been present for a considerable amount of time for a cavity to occur

Question 42

solubility

Answer 42

The degree to which a substance will dissolve in a given amount of another substance

Question 43

sand has low solubility bc..

Answer 43

it does not dissolve easily

Question 44

sugar has high solubility bc...

Answer 44

it does dissolve easily

Question 45

The mouth is exposed to many kinds of acids,

Answer 45

which can dissolve materials

Question 46

many sodas and sports drink have a very _____ pH

Answer 46

acidic

Question 47

Citric acid is added to many food to give them....

Answer 47

a tart taste

Question 48

For a dental material to have specific mechanical properties, steps must occur in the

Answer 48

application of the dental material

Question 49

What are the different properties of dental materials that may affect the application properties?

Answer 49

(Flow, adhesion which includes wetting and viscosity, retention, and curing.)

Question 50

flow

Answer 50

dental materials are designed to have a certain amount of flow for placement

Question 51

this allows the material to fill in the preparation of the tooth

Answer 51

flow

Question 52

When ______ that help prevent decay are placed on newly erupted permanent molars that are deeply fissured,

Answer 52

sealants

Question 53

the sealant material ___________ to plug up and protect areas that are not easily cleaned.

Answer 53

must flow well

Question 54

adhesion

Answer 54

the strength that causes unlike materials to adhere to each other

Question 55

without proper adhesion,

Answer 55

micro leakage can occur and restoration could come out

Question 56

Characteristics of dental materials that can affect the adhesion process are:

Answer 56

wetting, viscosity, surface characteristics, film thickness

Question 57

wetting

Answer 57

ability to flow over a surface

Question 58

viscosity

Answer 58

property of a liquid that causes it not to flow easily

Question 59

surface characteristics

Answer 59

influence the wetting ability

Question 60

film thickness

Answer 60

thinner means stronger adhesive junction

Question 61

adhesion may be thought of as placing....

Answer 61

tape on paper

Question 62

hydrophilic

Answer 62

water loving

Question 63

hydrophobic

Answer 63

water hating

Question 64

a hydrophilic surface would not wet well by a...

Answer 64

hydrophobic liquid

Question 65

A consideration in wetting is whether two materials are ......

Answer 65

hydrophilic (water loving) or hydrophobic (water hater)

Question 66

example of ideal film thickness

Answer 66

think of piecing together a broken china ornament using Krazy Glue rather than the thicker glue used in grade school craft projects.

Question 67

retention

Answer 67

The ability of holding two things firmly together when they will not adhere to each other naturally

Question 68

Even though retention holds the material in place,

Answer 68

it does not completely seal the two structures together.

Question 69

_________ can occur if an additional material such as a bonding material is not placed to create a seal.

Answer 69

microleakage

Question 70

Microleakage can occur if an additional material such as a ___________ is not placed to create a seal.

Answer 70

bonding material

Question 71

________ is very important in the preparation of teeth that are to receive amalgam fillings.

Answer 71

retention

Question 72

Retention is very important in the preparation of teeth that are to ____________________

Answer 72

receive amalgam fillings.

Question 73

One of the ways in which retention is achieved is preparing ....

Answer 73

the opposing inside walls of the tooth to slant slightly inward

Question 74

One of the ways in which retention is achieved is preparing the opposing inside walls of the tooth to slant slightly inward so

Answer 74

that when amalgam is placed and set it will not slide out.

Question 75

there are 2 types of retention....

Answer 75

mechanical and chemical

Question 76

The application of sealant is an example of .....

Answer 76

mechanical retention

Question 77

The _______ increases the surface area for retention and the sealant material flows into all the nooks and crannies on the surface of the tooth.

Answer 77

etchant

Question 78

curing

Answer 78

A setting process of a dental material that is initiated by a chemical reaction or by light in a blue wave spectrum

Question 79

auto cured

Answer 79

material hardens as a result of a chemical reaction of the materials once mixed together.

Question 80

light cured

Answer 80

material does not harden until it has been exposed to a curing light.

Question 81

dual cured

Answer 81

material, some curing takes place as the material is mixed. The final cure does not occur until the material has been exposed to a curing light.

Question 82

Bonded materials are set (hardened) by various means, including exposure to light of a particular ______. chemical reaction (auto), or a combination of the two.

Answer 82

wavelength

Question 83

Bonded materials are set (hardened) by various means, including exposure to light of a particular wavelength, _____________ , or a combination of the two.

Answer 83

chemical reaction

Question 84

Bonded materials are set (hardened) by various means, including exposure to light of a particular wavelength, chemical reaction (auto), or _______________

Answer 84

a combination of the 2

Question 85

What is an example of a dental material that has been the subject of a lot of public discussion about its safety?

Answer 85

amalgam, due to the mercury content, and other alloys