1386.12.2

A C R D

Specialized Symposium

A Dr. S. Nematipresentation

Light

Shadow

Light

Visible electromagnetic energy whose wavelength is measured in nanometer (nm) or billionth of a meter

The eye is sensitive to a narrow band 380-750 nm

Vision

Natural Tooth Is Polychromatic

The principles of Color

Light production

incandescence,Luminescence

incandescence,. The production of light from heat, or incandescence, is familiar to everyone. The Sun gives off both heat and light as a result of nuclear reactions in its core. An incandescent light bulb gives off light when a wire filament inside the bulb is heated to white heat. One can read by the light of a candle flame because burning wax gives off both heat and light.

LuminescenceThe term luminescence is used to describe a process by which light is produced other than by heating

A general term that describe any process in which energy is emitted from a material at a different wavelength from that at which it is absorbed

So ……

Fireflies have a bioluminescent organ in their abdomen that they use to attract mates. Chemicals within the organ react with oxygen to produce light. The insect

controls the flashes by regulating the flow of oxygen .

IridescenceIs the rainbow-like effect of different color which change according to the angle from which they are viewed

Iridescence is caused by multiple reflections from multi-layered,

materialBecause such intense reflection is usually seen from polished metal they look like metals

FluorescenceLuminescence that stops within 10 nanoseconds after an energy source has been removed.

is the absorption of light by a material and the spontanious emission of light in a longer wavelength

Absorption of UV and emission of visible light

For this to occur the emission must take place within 10 nanosec. after activation

phosphorescenceLuminescence that continues for more than 10 nanoseconds after an energy source has been removed.

Electron excitation

Light emitted by an atom or molecule persist after the exciting source is removed

It is similar to fluorescence but the species is excited to a metastable state from which a transition to the initial state is forbidden

1-Munsel color order system

2-CIELAB color system

HUE (name of color)

CHROMA (saturation)

VALUE (brightness)

Value is the most important factor in shade matching

HUE

Chroma

Value

A B C D

Value Sequencing

With a different shade guide sequenced in value order

B1 A1 B2 D2 A2 C1 C2 D4 A3 D3 B3 A3.5 B4 C3 A4 C4

Primary hues ( RYB)

Secondary Hues ( mix. Of 2 primary)

Complementary hues (directly opposite each other)

Complementary Colors

Enhance the appearance of each other

Primary hue + Complementary Secondary hue =cancel out both colors

ie: Gray

Clinical Tip To change hue, lessen chroma, or lower value , place the complementary hue over the color to be

modified

Back Ground Effect

بخوانید؟ را این توانید می

The Best Way for Color Matching Use 3 Light Source

Day Light Operatory LampCool White Fluorescent

Metamerism

There is more than one way to produce color1- pure color ( green)2 -mixture (blue + yellow)

Metamerism PURE GREEN GREEN (Y+B)

Opacity the ability of a material to block he passage of the light completely

(Dentin)

Transparencyis the ability of a material to allow the

passage of light completely(glass)

translucency

permitting light to pass through but diffusing it so that persons, objects, etc., on the opposite side are not clearly visible: Frosted window glass is translucent but not transparent.

Translucency provide realism

Optical absorption /scattering

Transparent …………………………………….both nil

Translucent………………………….…………..both low

Opaque ………………………………………….either or both high

OpalescenceOptical property in which there is a scattering in shorter wave length

It gives a material bluish appearance under reflected light

And orange / brown under transmitted light

Caused by particle transmitted in the material

Light

Short wave Long wave

Producing Opalescent Glass

To understand what opalescent glass is, has always been easy; to explain the process of making this glass is quite another matter. If you think of two layers of glass, one colored and one clear, that have been fused so that the clear areas become milky when fired a second or third time, the picture of the process becomes easier to see. It is, of course, much more complicated then that but for the sake of clarity; imagine the clear layer being pressed so that the second firing gives this opal milkyness to the outer edges, be it the design or the edges themselves, and the process becomes clearer. It is, of course, the skill of the glassmaker to control this opalescence so that it does what he wants. It is a fascinating process and anyone who has the privilege of watching a glassmaker at work can testify to it being a near-miracle.

Opaque halo

Opaque halo

Push the tongue against the teeth and the evaluate the halo the area between these 2 region is the area of blending tooth color with incisal color

1-Munsel color order system

2-CIELAB color system

CIELAB color system

For color research since 1979L a b L is similar to valueL describe the achromatic character of the color ---

CIELAB color system

a and b describe the chromatic character of the colora & b describe Hue and Chroma ….

E : the color difference is calculated from the sum of the squares of the differences among the three coordinates

Hue selection

The region with the highest chroma (cervical region of the canine )should be used for initial hue selection If the chroma is low accurately determining a given hue may be difficult

CLASSIC

3D MASTER

Chroma selection

When the hue is selected the best chroma match is chosen ….

Chroma selectionAfter Hue selectionB1 …………………….B4A1………………………A4……

Value selection

Finally value is determined with a secondary guide sample arranged in order of increasing lightness …..

B1 - A1 - B2 - D2 - A2 - C1 - C2 - D3 - A3 - B3 - A3.5 - B4 - C3 - A4 - C4

B1 A1 B2 A2 B3 A3 C1 B4 D2 A3.5 D4 D3 A4 C2C3 C4

Value Sequencing

With a different shade guide sequenced in value order

B1 A1 B2 A2 B3 A3 C1 B4 D2 A3.5 D3 A4 C3 C2 C4

1. Value selection in 5 level ( mid one) 2. Chroma selection (top to bottom) 3. Hue variation ( L to yellow , R to red)

First, determine the value (lightness) by selecting the closest match from one of five value groups .

Alternative way

Second, determine the Chroma within the value group from three choices .

To the yellow (L) or to the red (R)

Third, pick the hue by determining if the tooth has a more yellow or red cast.oth has a more yellow or red cast.

Extended shade guide

Dentin shade guide for full ceramic crowns to mimic clinical appearance

Color matching

A light source with a color temperature close to 5500 K that is spectrally balanced in visible spectrum is ideal for color matching

Lux is a unit of illumination Originally based on the illumination provided

by a house hold candle at a distance of 1 m

Affecting parameters

Dental operatory lampClothing of the dentistClothing of the assistanceClothing of the patientMake up color

Summary of guideline for visual shade matching

1. Balanced lighting2. Lipstick removed3. Teeth cleaned4. Beginning of patient visit (value increase when dry)5. Cheek retractor preferred6. Pt at eye level (most color sensitive part of retina is used)7. Pt distance # 25 cm8. Wet surfaces (both)9. Not more than 5 sec. staring10. Rest his eye ( at neutral gray not blue card , blue fatigue)11. Canine for hue guidance12. Staff cooperation13. If not an exact match possible a lower Chroma and higher value is preferred……………………..

Shade duplication errorsErrors associated with duplicating the selected shade of porcelain

1. Underlying metal used2. The batch of the porcelain powder3. The brand of the porcelain4. The number of times glazing performed 5. ………….

Thank you for your attention

Color measuring instruments Spectrophotometer use for measuring surf. Color measure a reflected light ratio from object to white

Spectroradiometer designed to measure radiametric quantities

measure light reflectance at wavelength intervals over the visible spectrum

spectrophotometer has a stable light source and an aperture between the detector and sample

Colorimeter useful for comparing 2 objectsProvide direct color coordinate specifications without mathematical

manipulation . Accomplished by sampling light reflected from an object through 3 color filter that simulate eye

Edge loss phenomenon

It occurs when light is scattered through a translucent material that originally would be seen by the eye but is simply not measured by the instrument

Color measuring instruments with an aperture between the translucent object and the illumination and sensor exhibit this phenomenon

Edge loss phenomenon

This happens when the light is scattered in a

translucent object away from aperture and does

not return back through the aperture to the

sensor and is wavelength dependent

Current shade measuring device

Shade Eye …...shofu dental ……colorimeter….…5500$

Easy shade ….Vident CA ..spectrophotometer….3000$

Shade scan…..Sinovad……..colorimeter………...3500$

Shade vision ...Xrite………...colorimeter ……..…5500$

Spectroshade..MHT switz...spectrophotometer…10,000$

Clear match….smart tech..….software…….……..3000$

1.    Antimony = Naples Yellow 1a.   Lead+Tin = Light bright Yellow 2.    Cadmium = Yellow, Orange, Red 3.    Chrome Green = Green        Chrome + Alumina = Translucent Corumdum Red        Chrome + Cobalt = Blue/Green        Chrome + Tin = Pink (light Magenta)        Chrome + Tin + Silica = Red        Chrome + Tin + Calcium = Red, Magenta, Violet        Chrome = Tin + Cobalt = Ultramarine Blue, Purple, Violet 4.    Chromium = Green Opaque        Chromium + Iron + Manganese = Black        Chromium Trivalent = Green        Chromium Hexavalent = Yellow 5.    Cobalt = Azure Blue        Cobalt = Uranium = Green        Cobalt + Zinc = Ultramarine Blue        Cobalt + Chromium + Manganese = Black 6.    Copper = Green, Turquoise, Red, Ruby Red Violet        Copper Oxide = Green        Copper Oxide + Zinc = Brilliant Green

7.    Ferris Oxide Lead Silicate = Yellow        Iron = Green, Yellow, Orange, Red, Brown, Black, Cyan, Ultramarine Blue        Iron Oxide = Opaque Brown to Red 8.    Gold = Magenta 9.    Lead = Yellow        Lead + Chromate = Red        Litharge = Red Minium (Roman) 10.   Divalent Manganese = Yellow to Brown        Manganese = Brown, Red, Magenta, Purple, violet 11.   Magnetite = Black 12.   Molybdenum = Smokey Gray to Blue 13.   Nickle = Gray, Blue, Purple, Green, Yellow, Brown        Nickle Oxide = Slate Blue Gray 14.   Potassium Oxide = Yellow Green

15.   Platinum = Silver 16.   Silver = Dull Silver        Silver Chloride = Yellow Side Silver 17.   Selenium + Cadmium + Sulphur = Red        Selenium + Cadmium = Orange        Selenium + Sulphur = Yellow 18.   Salt fires clear Glossie 19.   Tin = White        Tin + Chrome = Crimson        Tin + Vanadium = Yellow 20.   Titanium = Opaques 21.   Uranium = Red, Black 22.   Vanadium = Emerald Green, Yellow Green, Yellow, Orange, Red, Brown 23.    Zirconia = Pink, Magenta        Zirconium + Vanadium = Cyan, Turquoise 24.   Clay = Glossie Red Oxide (Terra Sigillata, Roman) 25.   Clay = Black (Terra Nigra, Roman)

WHITEGYPSUM, native calcium sulfate, calcined 250 degrees. IRON, native ore calcite, oxide. LEAD, Lead white, "ceruse", basic sulfate of lead, native or burnt galena ore. LEAD, "White vitriol", made with sulfuric acid fumes. LEAD, Lead white carbonate oxide, made by acetic acid fumes and carbonic acid fumes on lead in a closed container. MAGNESIUM, carbonate found native, the whitest ore pigment. MICA. Silicate laminated natural, native. Japanese pigment. SHELL, powered. TIN. Calcined tin oxide. ZINC oxide found native. ZINC "White Vitriol", made with sulfuric acid fumes.

BLACKBONE and HORN. Roman "atramentum", charred deep black. CARBON. Oil soot, lamp black. IRON. Iron oxide, native. MANGANESE. Black manganese dioxide native, ancient "pyrolusite". ROCK, Slate gray, crushed. SULFUR. Ultramarine ash, the first washing contains some matrix rock, this leaves a cool opaque gray.

YELLOWARSENIC. Orpiment, arsenic sulfide, native, Egypt early, 3000 B/C. ANTIMONY. Naples yellow, native, 500 B/C, replenished 79 A/D in the Visuvious eruption. IRON. Yellow ocher natural, "minette", "sil", "chamois", heated to gold ocher, flesh ocher and red. IRON. Raw sienna, heated to burnt sienna and translucent vermilion hue. Rubens used this glaze IRON. Amberg yellow, a very bright fresco yellow ocher no longer available, except at Kramer in Germany, native. LEAD. Lead oxide white heated to a cool yellow, "Massicot", "King's Yellow", "Cassel Yellow", lead also heated to orange, red and brown. LEAD-TIN. Lead-tin Yellow is a light cool yellow often mistaken for Naples Yellow. ORGANIC-ANIMAL. Indian yellow is magnesium euxanthate, an early dye used in, sandarac, (Sandracca), mastic, and oil pigment until 1899. Made from cows urine, India. Yellow to brown and brown, orange to yellow, transparent. ORGANIC-PLANT. Tree sap, "gamboge" translucent yellow, alcohol base, Thailand. ORGANIC-PLANT. "Turmeric" root, "curcuma" root, transparent yellow to brown, India, Asia. ORGANIC-PLANT. "Saffron", flower power, bright yellow, India. TIN. calcined from white to pale yellow.

ORANGEARSENIC. Realgar, arsenic di-sulphide, native, Egypt 3000 B/C. "Risalgallo", Roman, red-orange clear crystal. IRON. In clay, burnt sienna, high in silicic acid until calcined from raw sienna, than it's high in silica and is transparent. TIN, calcined from pale yellow to pale orange. ZINC. Zincite, native zinc oxide, ore of zinc, a brittle mineral ranging in color from yellow, orange to deep-red, opaque. The word "orange" comes from the Sanskrit "naranga" which was related to the Tamil word "naru" meaning fragrant.

REDCOPPER. Cupric crystals native, transparent red. That is the opposite of the copper pigment color. HEMATITE IRON, ore, native red streaks of iron oxide, where abrasion has ground off hematite ore in place. IRON, in clay, "cinabrese", Cennini described a native light vermilion red hue good for flesh colors IRON, in clay, "Armenian bole", red ocher. IRON, in clay, "sinopia", native red oxide, Roman 100 B/C IRON, in clay, "sinopis", a very light red ocher from Asia Minor, exhausted. LEAD. "Minium", red lead oxide is made by heating white lead in the presence of air, turns dark in fresco as all leads do, this was a mastic, oil and wax pigment that is unaffected by alkalis. Phoenician, 1000 B/C, Greek, Roman, 500 B/C. MERCURY. "Cinnabar" native, is the ore of mercury. "Vermilion" natural was one of the two most prized and expensive pigments of the ancients, not counting gold. Mercuric Sulfide. ORGANIC-PLANT SAP, Brazilwood lake, blood red transparent. "Dragon's Blood", ruby red lac, Singapore, as ancient as karmes. ORGANIC-PLANT FLOWER. Safflower red, "Carthame". ZINC. Zincite red, native red oxide zinc ore. The word "red" came from the Sanskrit word "rudhiras".

Thank you for your attention

Esthetic smile

In general an extensive smile that showed the complete outline of the maxillary ant. Teeth and teeth posterior to the first molar was considered the most attractive and youthful

An aging smile shows less maxillary incisor and more mandibular incisors

Buccal corridorIs the space between the teeth and the cheeks in a smile and

Is related to the width of the dentition and the width of the mouth during smile

Smile arc

The relative curvature of incisal edge of the maxillary teeth and the curvature of the lower lip

In attractive smiles these curvatures are very similar . .

proportion

Golden proportion 0.618 # 60% in frontal view

In glorious architectural monument this ratio has been employed progressively

Balance

Including the location of midline

Mean threshold for facial and dental midline deviation is 2.2+/- 1.5 mm