Properties of Dental Materials

Question 1

stress is blank property

Answer 1

mechanical

Question 2

push or pull that has a magnitude and direction

Answer 2

force

Question 3

force is measured in blank

Answer 3

newtons

Question 4

when a force acts on a body, a blank is developed to this external force

Answer 4

resistance

Question 5

internal reaction to the external force

Answer 5

stress

Question 6

stress is measured in force per blank

Answer 6

unit area

Question 7

stress hase these units

Answer 7

N/m^2 (Megapascals MPa)

Question 8

two forces directed away from each other in a straight line

Answer 8

tension

Question 9

load of tension tends to blank a body

Answer 9

stretch/elongate

Question 10

two forces directed toward each other

Answer 10

compression

Question 11

compression load blank a body

Answer 11

shortens

Question 12

compression internal resistance is blank

Answer 12

compressive stress

Question 13

glass is great at handling blank forces but not blank

Answer 13

compressive, tension

Question 14

stress that is a result of two forces directed toward each other but not in the same plane

Answer 14

shear

Question 15

most common missing tooth

Answer 15

first molar

Question 16

complex stress example

Answer 16

bridge during mastication

Question 17

most destructive force

Answer 17

shear

Question 18

stress when a body undergoes deformation when a force is applied to it

Answer 18

strain

Question 19

strain =

Answer 19

deformation / original length

Question 20

graphical method of studying the stress strain relationship of a dental material

Answer 20

stress strain curve

Question 21

maximum stress that a material will withstand before permanent deformation

Answer 21

proportional limit (elastic limit)

Question 22

stress strain curve is no longer straight and is curved because new shape will never go back to old shape

Answer 22

plastic deformation

Question 23

point of deformation is aka the blank

Answer 23

yield point

Question 24

point at which material fractures

Answer 24

failure point

Question 25

material is considered strong when the proportional limit is blank

Answer 25

high

Question 26

property of having a constant ratio of stress to strain

Answer 26

elasticity

Question 27

distance that the wire will bend elastically before permanent deformation occurs

Answer 27

range (elastic strain)

Question 28

describe relative stiffness or rigidity of a material

Answer 28

modules of elasticity

Question 29

when the proportional limit is exceeded, the material exhibits blank behavior

Answer 29

plasticity

Question 30

materials that have little plastic behavior are blank

Answer 30

brittle

Question 31

area under the elastic portion of the ss curve

Answer 31

resilience

Question 32

ability of a material to withstand permanent deformation under a compressive load without ruptures

Answer 32

malleability

Question 33

ability of a material to withstand permanent deformation under a tensile load without ruptures

Answer 33

ductilitty

Question 34

area under elastic and plastic portions of ss curve combine

Answer 34

toughness

Question 35

ductility and malleability are area under ss curve in the blank portion

Answer 35

plastic

Question 36

strain that occurs when the material is stressed to its proportinoal limit

Answer 36

stiffness/springiness

Question 37

springiness =

Answer 37

1/stiffness

Question 38

stiff has a blank slope compared to springy in the ss curve

Answer 38

steeper

Question 39

small surface cracks grow larger and larger upon cycling, until fracture

Answer 39

fatigue

Question 40

reaciton of a stationary object to a collision with a moving object

Answer 40

impact

Question 41

three physical properties

Answer 41

mechanical, thermal, electrical