E3: COLOR, light, and shade!!! Flashcards
What is the range of the visible spectrum? What color is at the low end? What color is at the high end?
380-750nm…red at HIGH end (INFRAred- LONG waves) and Purple at LOW end (ULTRAviolet-short waves)
What color light do we see when ALL the colors are placed together?
White light
BIGGEST THEME OF ENTIRE LECTURE: What are the 2 factors considered when selecting a LIGHT SOURCE?
- the C-R-I Color Rendering Index and 2.Color Temperature
What is the OPTIMAL C-R-I??? What is this optimal CRI compared to?
100…in reference to Northern Daylight
Morning and Evening: SHORTER wavelengths SCATTER before penetrating the atmosphere, therefore it is rich in _______ and lacks ________
rich in YELLOW/ORANGE(longer) and lacks blue/green (shorter)
What is the ideal time of day for natural day light?
NOON. full spectrum visible
WHOLE POINT OF LECTURE: A light source with a CRI greater than ___ is recommended for shade matching…Wait what does CRI stand for again???
90…Color Rendering Index
Zoomed over-what is the Temperature of the IDEAL Northern Daylight?
6500Kelvin
___________ Light - emit higher concentrations of YELLOW light waves and is not suitable for shade matching.
InCanDescent Light
___________ Light - give off higher concentrations of BLUE waves. Common bulbs (CRI= 50-___) therefore not suitable for shade matching
Fluorescent…50-80 CRI
What color is the fluorescent light again?
BLUE
What are the three aspects of determining color?
Hue, Chroma, Value
What are the two systems for determining color?
1.MUNSELL and 2.C-i-E-Lab
What are the 3 primary subtractive colors?
Red, Yellow, Blue
What are the three secondary subtractive colors?
Green, Purple, Orange
What color occurs when all the PRIMARY subtractive colors are combined?
black
What are the colors obtained from emitting light? (TV and computer)…What are the 3 PRIMARY specific colors? What are the 3 secondary?
Additive…Red Green Blue…secondary: Cyan, yellow, Magenta
Munsell: The shorter the wavelength the closer the hue is to _____, longer the wavelength the closer the hue is to ___. Hues are arranged around the wheel.
violet….red
What are the two words to describe Chroma?
Saturation and Intensity
VALUE: _____ your eyes, dawg! What is the intensity of black in LOW value?
SQUINT your eyes!….LOW VALUE = BLACK. high value = White/light gray
Restorations TOO ____ in VALUE are EASILY detected!!!
HIGH in value (lighter grey/white)
What is the value range of NATURAL TEETH?? dark—>light
5.5—8.5
AGAIN: A restoration too _____ in value is easily detected by an observer and a common mistake in metal-ceramic prosthodontics
HIGH (too light!!) Toilet Bowl White!!!
Objects of different chroma / hue can be identical _____
value
It is a better system then Munsell system because of the magnitude of perceptibility:
C-I-E-Lab
What are the 3 coordinates of the C-I-E-Lab color system?
1.L-lightness (Value in munsell) 2.A- Chromatic characteristics of color: Red-purple/Blue-Green Axis 3.B-Chromatic characteristics of color: Yellow/purple-blue axis
Rods =
Black and White
Cones =
Color
Color vision decreases RAPIDLY! Don’t worry, you can restore color vision by:
Viewing a pale BLUE or GRAY surface between shade matching will restore color vision!! COOL!
That COOL,tricky picture of the same shade squares under different light sources is called:
Metam-erism
Use of the operatory light is ___ recommended.
NOT
What % of males are color blind? Females?
8% males…0.5% females
MAIN POINT OF LECTURE: What is the sequence of evaluating a color in the Munsell System?
1.Hue 2.Chroma 3.Value
MAIN POINT OF LECTURE: What is the sequence of evaluating a color in the C-I-E-Lab system?
1.VALUE 2.Chroma 3.Hue
The overall shade must blend well with the
contralateral and ________ teeth.
ADJACENT!
WHEN do we take the shade?
Beginning of Appointment!
What type of cement is used for translucent crowns?
Resin cement
Vita Classic Shade guide uses the _______ color system.
Munsell
The VitaPan 3D and Extended Range shade guides use the _______ color system
C-I-E-Lab
VITA: the A range is for the colors ________
red-yellow
VITA: the B range is for the colors ________
yellow
VITA: the C range is for the colors ________
gray
VITA: the D range is for the colors ________
Red-yellow-gray
VITA: the Chroma is indicated with _______ values
numerical- A3 = chroma of 3
***Use area of tooth highest in chroma for hue selection ( Cervical region of ______)
CANINE
Squinting eyes for Value: The one that fades first has the _____ value.
LOWER (black)
*** If the value of the shade tab is _____ (_____) than that of the natural teeth, a change is usually necessary!!
LOWER (darker)
increasing the ______ of a restoration is not possible by means of staining.
value
Don’t worry if your restoration has a ______ (_____) value than the natural teeth, it can be adjusted with staining!!
higher (lighter)
Vita-3D: 1st select _____..The ______ group will be on the left and the ______ on the right.
VALUE…dark left…light right
Step 2 of vita-remove the 3 ___ tabs to determine chroma
M
What is the 3rd step of Vita 3D? What are the options?
Determine the hue- L M or R
