Brainscape's Knowledge GenomeTM

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


See full index

Biomaterials > Optical Properties > Flashcards

Optical Properties Flashcards

1
Q

Color is the border bw the ___ and ___

There should be ___ ____ dentistry

“Fcnal dentistry” should still be ____

A

Color is the border bw the esthetic and nonestheticThere should be no nonesthetic dentistry

“Fcnal dentistry” should still be esthetic

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

Rationale: Why study color in dentistry?

___
___
____

A

Rationale: Why study color in dentistry?

Clinical: It is our task

Scientific: We can make it better

Commercial

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

ΔE*

Change in ___

Not ___ to color and sight

There are ΔE* for___ too

If it equals 0, that is a ___ ___

A

ΔE*

Change in sensation

Not exclusive to color and sight

There are ΔE* for hearing too

If it equals 0, that is a perfect match

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

Perceptibility and Acceptability Thresholds

ΔE*= ___

50:50% perceptibility threshold, _____ for 50% of observers under controlled conditions

Perceivable difference by ½ of people

50% see the difference

ΔE*= ____

50:50% acceptability threshold, ____ for 50% of observers under controlled conditions

More-_____ than 1.2

We need to be within acceptable difference

___ the better

A

Perceptibility and Acceptability ThresholdsΔE*= 1.2

50:50% perceptibility threshold, detectable for 50% of observers under controlled conditions

Perceivable difference by ½ of people

50% see the difference

ΔE*= 2.7

50:50% acceptability threshold, acceptable for 50% of observers under controlled conditions

More important than 1.2

We need to be within acceptable difference

Smaller the better

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

Over ___% of patients were aware of the color difference between the____ and the adjacent ___ ___

Correct match ___ (2.7) of 16 pairs of tabs of 2 shade guides

People asked to match 16 pairs of 2 shade guides

Each shade guide has 16 tabs.

Take 16 from one and 16 from the other and match the pairs

The matched ½

Those that match 16/16

____

Able to participate in__ ___

An average shade matching error: __ Vita Shades

A

Over 80% of patients were aware of the color difference between the restoration and the adjacent natural teethCorrect match 7.7 (2.7) of 16 pairs of tabs of 2 shade guides

People asked to match 16 pairs of 2 shade guides

Each shade guide has 16 tabs.

Take 16 from one and 16 from the other and match the pairs

The matched ½

Those that match 16/16

Competent

Able to participate in color research

An average shade matching error: 4.0 Vita Shades

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

Shade matching reproduction of ceramic disks–>monochromatics

Vitspan Classical/VMK 68- ΔEab = ___

This is over the accepted value

ShadeEye-EX/Vintage Halo- ΔEab = ___

Vitaspan 3-D Master/Omega 900- ΔEab =___

A

Shade matching reproduction of ceramic disksà monochromaticsVitspan Classical/VMK 68- ΔEab = 3.5

This is over the accepted value

ShadeEye-EX/Vintage Halo- ΔEab = 4.5

Vitaspan 3-D Master/Omega 900- ΔEab = 6.8

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

An average ΔEab = ___ was recorded among metal ceramic crowns made by two operators

Two technicians in the same room making the same thing

Tooth before preparation and crown before cementation: ΔEab = ___

Scary!

That is why all white is so safe, you can’t make a mistake

A

An average ΔEab = 3.6 was recorded among metal ceramic crowns made by two operators

Two technicians in the same room making the same thing

Tooth before preparation and crown before cementation: ΔEab = 10.5

Scary!

That is why all white is so safe, you can’t make a mistake

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

The field of esthetic dentistry has exploded in the last few years. Some 15 years ago, esthetic dentistry accounted for less than ___% of the money spend on dental care, now it exceeds __%.

Commercial

We are not all gifted for shade matching

Only __% are

A

The field of esthetic dentistry has exploded in the last few years. Some 15 years ago, esthetic dentistry accounted for less than 20% of the money spend on dental care, now it exceeds 70%.

Commercial

We are not all gifted for shade matching

Only 16% are

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

Psychophysics

Scientific discipline dealing with ____ relations between ___ ___i and ____s they cause

A

Psychophysics

Scientific discipline dealing with mathematical relations between physical stimuli and sensations they cause

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

Colorimetry

____ of color based on a __ of ____

Color is not trivial addition or subtraction

A

Colorimetry

Measurement of color based on a set of conventions

Color is not trivial addition or subtraction

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

Color

___ ___ provoked in the___ by the__ ___ and interpreted by the ___

Brain tells us based on our stored memory what we ___ we see.

We look at the light ____ from the tooth

A

ColorPsychophysical sensation provoked in the eye by the visible light and interpreted by the brain

Brain tells us based on our stored memory what we think we see.

We look at the light reflected from the tooth

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

Visible part of the spectrum: 400-700 nm

This is all we see

A

Visible part of the spectrum: 400-700 nm

This is all we see

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

Light Source

Any___or ___y ___ ____in the ___ ___ range

A

Light Source

Any area or body emitting radiation in the visible spectra range

Primary

Lamp

Secondary

Tooth

Light comes to our eyes from the tooth

Natural

Sun

Artificial

Any other

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

Three things that define any color

___ ___ ___

A spectral characteristic of the ___ ___ ___ heated to a +__ ____ and expressed in _.

Daylight: ___

___ ___ ___ (CRI)The___ scale is used to show the relation bw the ___ and the___ light source (CRI=___)

How well does it represent ideal light

100 is ___

__ and above is what you want for dental shade matching

__ ___ ____ (SED)

Color “___” represented by __ ___

A

Three things that define any colorCorrelated Color Temperature

A spectral characteristic of the black body radiator heated to a certain temperature and expressed in K.

Daylight: D65

Color Rendering Index (CRI)The 0-100 scale is used to show the relation bw the examined and the standard light source (CRI=100)

How well does it represent ideal light

100 is perfect

90 and above is what you want for dental shade matching

Spectral Energy Distribution (SED)

Color “fingerprint” represented by reflection curve

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

Standard Light sources are

A:

B:

C
D65: daylight

A

Standard Light sources are

A:

B:

C
D65: daylight

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q
  • When light strikes a surface, the change in___ ___can cause light to be ____ by the surface antr-=d/or p___ the ___y of the material
  • Reflection:
    • Process by which ___ is ___ by a surface, ___ reflection or a ___-___ reflection
  • Volume reflection
    • Teeth are not transparent. They are ____ so some light will get refracted.
    • Light travels further than the surface of the tooth
      • Sometimes all the way to dentin
        • Dentin is more ___ (opaque) so majority of light is reflected from it
        • Reflection from the ___
A

When light strikes a surface, the change in refractive index can cause light to be reflected by the surface and/or penetrate the body of the material

Reflection:

Process by which radiation is returned by a surface, surface reflection or a medium-

Volume reflection

Teeth are not transparent. They are translucent so some light will get refracted.

Light travels further than the surface of the toothSometimes all the way to dentin

Dentin is more colored (opaque) so majority of light is reflected from it

Reflection from the inside

17
Q
  • …≥÷Angular Distribution+
  • ____l reflection + ___ reflection= total reflection
  • Spectral Reflection: ____ reflection
    • The same but opposite angle
    • In dentistry we call this ___
    • Shiny teeth
  • ____e Reflection
    • Any ___ ___of reflection
A

Angular Distribution

Spectral reflection + diffuse reflection= total reflection

Spectral Reflection: mirror reflection

The same but opposite angle

In dentistry we call this gloss

Shiny teeth

Diffuse Reflection

Any other angle of reflection

18
Q
  • àsz1`m v\
  • ,Absorption
    • The phenomenon in which light is ___ ___ or ___ by the object
  • Transparency
    • ____ of light____ an object with___ ____
    • Ex) ___ ____
    • ____
  • Translucency
    • ___ of light permitted but light is ____
    • Ex) ___ ____, ___
    • Light ____ so its not really clear
A

Absorption

The phenomenon in which light is absorbed fully or partially by the object

Transparency

Passage of light thru an object with little distortion.

Ex) Incisal porcelain

Clear

Translucency

Passage of light permitted but light is distorted

Ex) Body Porcelain, Composite

Light changes so its not really clear

19
Q

Opacity

Optical property that ___ ___ of ____

Opaque medium is the medium that ___ __ ___ in the __ __ of ____

Ex)___ ____

Opposite of____

Absolute opacity is _ translucency and vise versa

A

Opacity

Optical property that prevent passage of light

Opaque medium is the medium that transmit no radiation in the spectral range of interest

Ex) Opaque Porcelain

Opposite of translucency

Absolute opacity is 0 translucency and vise versa

20
Q

Fluorescence

Process by which___, usually ___, is ___ by certain chemicals or materials and ____ at other, usually ____ wavelengths

Property of our dental tissue and materials

A

Fluorescence

Process by which Energy, usually UV, is absorbed by certain chemicals or materials and re-emitted at other, usually longer wavelengths

Property of our dental tissue and materials

21
Q

Opalescence

The material appears _______ in ____ light and___ in ____ light perpendicular to the____ light

A

Opalescence

The material appears yellowish-red in transmitted light and blue in scattered light perpendicular to the transmitted light

22
Q

Eye: All visually sensations are brought to the brain through the ___

A

Eye: All visually sensations are brought to the brain through the eye

23
Q

Retina

A complex mosaic of millions of ___ ____

Rods only record ___

They see in black and white

Cones: Nerve endings that enable __ ___

Sensitive to

Blue

Green

Red

A

Retina

A complex mosaic of millions of nerve endings

Rods only record light

They see in black and white

ConesNerve endings that enable color visionSensitive to

Blue (S)

Green (M)

Red (L)

24
Q

Brain

On reaching the brain, the ____, the messages from rods and cones will connect the picture ____ with something ___ ___.

A

Brain

On reaching the brain, the interpreter, the messages from rods and cones will connect the picture presented with something previously experienced

25
Q

Females are better ___ ___ than men

Color Deficiency

A ____ hereditary color vision disorder that occurs as a consequence of abnormality on __ csome.

Women___ and men ___ color deficiency

__ of males

__ of females

  • Need __ ___to be color deficient

Among color normal individuals, there is __ ___ bw __ and ___

No one is color blind unless they are blind. We all see colors. Some people are deficient

A

Females are better shade matchers than men

Color Deficiency

A recessive hereditary color vision disorder that occurs as a consequence of abnormality on X csome.

Women bring and men inherit color deficiency

8% of males

0.5% of females

Need both parents to be color deficient

Among color normal individuals, there is no difference bw males and females

No one is color blind unless they are blind. We all see colors. Some people are deficient

26
Q

Computer simulation

Allows us to compare how a normal person would see colors vs. people deficient is R G or B

____ L: Red deficiency

___: M: Green deficiency

____: S: Blue deficiency

__ and ___deficiencies look similar

A

Computer simulation

Allows us to compare how a normal person would see colors vs. people deficient is R G or B

Protanope: L: Red deficiency

Deuteranope: M: Green deficiency

Tritanope: S: Blue deficiency

Red and Green deficiencies look similar

27
Q

Chromatic Adaptation

The inability of ___ the color of the ___ scene when the ___ ___ is ___

A

Chromatic Adaptation

The inability of changing the color of the viewed scene when the light source is changed

28
Q

Metamerism: 4 definitions and they are all correct:

Change of __ ___ of 2 objects viewed under ___ ___sources

Two color samples appear to ___ ___ ___ ____ but not under another

____match: They look the same under one light and look different under a different light

______match

____: The opposite

  • ____match
  • They are the ___ thruout the visible spectra range
A

Metamerism4 definitions and they are all correct:

Change of color matching of 2 objects viewed under different light sources

Two color samples appear to match under one condition but not under another

Conditional match: They look the same under one light and look different under a different light

Non-spectral match

Isomerism: The opposite

Unconditional match

They are the same thruout the visible spectra range

29
Q

Dichroism

Refers to a situation when the color of an object, viewed by ____ light may be different according to the____ of the sample viewed (blood, water..)

Thickness is the essence of color reproduction

A

Dichroism

Refers to a situation when the color of an object, viewed by transmitted light may be different according to the thickness of the sample viewed (blood, water..)

Thickness is the essence of color reproduction

30
Q
  • Primary Colors
    • __
      __
      ​__
  • Secondary Colors
    • The ___of any ___ __ ___
    • Yellow:
    • Cyan:
    • Magenta:
  • Complementary Colors
    • ___on the ___ sides of the color wheel
    • Used extensively
  • Shades
    • Colors with ___ of ___ added to a__ __
A

Primary Colors

Red

Green

Blue

Secondary Colors

The blend of any two primary colors

Yellow: Red and green

Cyan: Blue and green

Magenta: Blue and red

Complementary Colors

Hues on the opposing sides of the color wheel

Used extensively

Shades

Colors with quantum of black added to a base color

31
Q
  • Additive mixture
    • Mixing of colored ____
    • The mixture results in the occurrence of ___
  • Subtractive mixture
    • Mixing of colored substances and ___
    • The mixture results in the occurrence of ___
A

Additive mixture

Mixing of colored lights

The mixture results in the occurrence of white

Subtractive mixture

Mixing of colored substances and pigments

The mixture results in the occurrence of black

32
Q

Visual Comparison

A comparison with some known ___ ___ accepted as ___

___ Book of Color

Dental ____ ____

A

Visual Comparison

A comparison with some known physical standard accepted as referral

Munsell Book of Color

Dental Shade Guides

33
Q

Color measuring instruments

Designed to overcome ____, the major drawback of ___ ___ ____

Parameters that have to be defined

___ ___

___ ___ ____

___ ____

___ ___

Instruments are designed response on the reaction of the human eye

A

Color measuring instruments

Designed to overcome subjectivity, the major drawback of visual shade matching

Parameters that have to be defined

Light source(s)

CIE standard observer(s)

Optical geometry(s)

Colorimetric System(s)

Instruments are designed response on the reaction of the human eye

34
Q

Optical GeometryBroken down into:_____t Geometry

First number is always ____ geometry

____ geometry

A

Optical GeometryBroken down into:Illuminant Geometry

First number is always illuminant geometry

Viewing geometry

35
Q

Hue (H): ___ ___

Dimension that enables differentiation between ___ ___

Placed in a closed __ ___

360 degrees

Different degree means different color

A

Hue (H): Color Name

Dimension that enables differentiation between color families.

Placed in a closed hue circle

360 degrees

Different degree means different color

36
Q

Value (V): __ ___

Value or ____ is a dimension that enables discrimination between___and ____ color and is represented as a _______

Black (___) to white (___) with many shades of grey in bw

A

Value (V): No color

Value or lightness is a dimension that enables discrimination between light and dark color and is represented as a black-white axis

Black (bottom) to white (top) with many shades of grey in bw

37
Q

Chroma (C): ___ ____

Enables differentiation between __ and __colors

Presented as the distance from the ____ (___ axis)

Pale to strong

Same color but differ intensity

Close to center is ____

Farther out:___

A

Chroma (C): Color Strength

Enables differentiation between pale and strong colors

Presented as the distance from the vertical (achromatic axis)

Pale to strong

Same color but differ intensity

Close to center is pale

Farther out: stronger

38
Q

CIELAB system Color coordinates:

L* :

____, ___

a*
____

b*
_____

C*
___

H°
___

H and C are calculated mathematically from_____

Color difference between the compared colors is expressed in ____ units and it represents the ___ ___ __ ___ ___ ____ ((_ _ _ or _ _ _°)

A

CIELAB system Color coordinates:

L* :

Lightness, black-white

a*
green-red

b*
blue-yellow

C*
Chroma

H°
Hue

H and C are calculated mathematically from a and b

Color difference between the compared colors is expressed in ΔE* units and it represents the sum of all coordinate color differences ((L*, a*, b* or L*, C*, H°)

39
Q

Munsell System

Not used anymore because of problems with numbers

But it is the same

Black to white

Different hue

Different chroma

A

Munsell System

Not used anymore because of problems with numbers

But it is the same

Black to white

Different hue

Different chroma

Biomaterials (15 decks)

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