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IN THE NAME OF GODIN THE NAME OF GOD IN THE NAME OF GODIN THE NAME OF GOD

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COLOR COLOR &&

LIGHT LIGHT

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COLOR IS PROBABLY THE MOST COLOR IS PROBABLY THE MOST IMPORTANT DETERMINANT OF IMPORTANT DETERMINANT OF

EASTHETICSEASTHETICSIN PROSTHODONTICSIN PROSTHODONTICS

► ESTHETIC IS THE FIRST DEMAND OF ESTHETIC IS THE FIRST DEMAND OF PATIENTSPATIENTS

.

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THE EYE AND COLOR PERCEPTION

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The nature of lightThe nature of light

►Light is electromagnetic (EM) radiation, the fluctuations of electric and magnetic fields in nature

►Light has the properties of both particles and waves.

►Light particles, called photons, radiate from their source in a wave pattern at a constant speed of 186,000 miles per second.

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► They are measured by wavelength, the distance between two crests (in meters or, sometimes, in angstroms which are 1/100,000,000th of a meter), and by amplitude, the vertical distance between the crest and the trough.

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The part of the spectrum below 380 includes:

ultravioletx-ray

gamma raysThe wavelengths longer than 750:

infrared microwaves

Television and radio waves

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THE NATURE OF LIGHTTHE NATURE OF LIGHT

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PURE WHITE LIGHTPURE WHITE LIGHT

► Equal quantitition of energy over the visible range

► When passed through a prism white light is broken down into its component wave lenghts

► Longer waves are reflected less than shorter ones

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CCOOLLOORR

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COLOR MEASURMENTCOLOR MEASURMENT

►HUEHUE

►VALUE VALUE

►CHROMACHROMA

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►Color Color ►ShadeShade

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CChhrroomama

►SaturationSaturation►PurityPurity

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VVaalluuee►Achromatic Achromatic ►Brightness Brightness ►BrillianceBrilliance

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Additive Subtractive

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Subtractive color mixingSubtractive color mixing

► Primary colors: red yellow blue

► Secondary colors : orange green violet

► Complementary colors

Black

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Additive color mixingAdditive color mixing

•. Primary colors Red Green Blue • Secondary colors :Yellow Cyan Magenta

•Complementary colors

White

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Opacity , Translucency , Opacity , Translucency ,

TransparencyTransparency

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Translucent Translucent

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FACTORS EFFECTING COLOR FACTORS EFFECTING COLOR PERCEPTIONPERCEPTION

►DECEPTIVE COLOR PERCEPTION : complementary color effects each other and when placed side-by-side they may appear to increase chroma

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FACTORS AFFECTING COLOR PERCEPTION

►COLOR BLINDNESS: very few cannot see color at all,most have an inability to detect the differences in chroma (this is called monochromatism)

►requires then an alternative method of shade selection:

-use of office staff-spatial training to overcome or adapt

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LIGHT IN DENTAL OFFICELIGHT IN DENTAL OFFICE

► Most common lighting is either:

► incandescent► fluorescent► Neither is pure white

light ► -incandescent is

higher yellow than blue

► fluorescent is higher than blue waves

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METAMERISMMETAMERISM

► AN OBJECT APPEARS TO BE INDIFFERENT COLORS WHEN VIEWED WITH DIFFERENT LIGHT SOURCES

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METAMERISMMETAMERISM

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