Basic Principles of Dental Esthetics Flashcards
(37 cards)
Are short or long light waves more dangerous?
Short waves are more dangerous (such as cosmic rays)
Longer waves are not as dangerous (radio)
Additive colors
RGB
If you combine colors, you get more colors
All colors together are white
Subtractive colors
CMY
If you combine colors, you get less color
All colors together are black
T/F - Additive colors and Subtractive colors are the reverse of each other
True
What are the 3 dimensions of color?
Hue
Chroma
Value
Munsel sphere v. CIE
They are the same concepts, but different scales
Banana shaped region
Region on the CIE where teeth colors are located
It’s banana shaped
Hue
What we think of as ‘color’
Chroma
Saturation
The intensity of the color
“If you add more food coloring to water, you get more chroma”
Value
How light the color is
What is color temperature measured in
Kelvin
What are factors that effect color perception?
The eye (rods and cones) Color adaptation Deceptive color perception Metamerism Fluorescence Opalescence Color blindness
What is the color of human teeth
Teeth don’t have a single uniform color
What site of the tooth represents color best?
Middle site
Incisal and cervical sites are affected by the surroundings
How do women’s teeth compare to men’s?
Women have lighter, less saturated and less reddish teeth
What are the ideal circumstances for shade selection
Neutral environment
No makeup
Rapid shade comparison and gaze at a blue card
Asses value by squinting
Rapidly scan shades to discard colors
Compare under varying conditions (wet/dry)
Check shade under different light sources
Use canines as references (highest chroma)
Check adjacent shades of teeth for variations
If you are unable to match shades, which should you select? Why?
Select the lower chroma and higher value
This is because it will look lighter, and it’s easy to darken it if necessary
T/F - Shade guides fully duplicate natural tooth color
False
Why is there a lack of consistency in shade choice among dentists?
Duplication of choice is difficult
Natural tooth colors are not fully duplicated in shade guides
Color perception varies between individual dentists
T/F - Bleached teeth will stay their whitest color
False - due to dehydration, bleached teeth will usually rebound 1/2 shade following bleaching
Structure of enamel
97% HA Protein = amelogenin Cells = ameloblasts Microenvironment = sealed Maintenance = none
Structure of Dentin
67% HA Protein = collagen Cells = odontoblasts Microenvironment = moserately leaky Maintenance = odontoblastic process
Structure of Cementum
45-50% HA Protein = collagen Cells = cementoblasts Microenvironment = cells widely spaced Microenvironment = cementocytes
What is the mechanism of bleaching?
Oxidizing agent (H-peroxide, Carbamide peroxide) diffuses and penetrates through enamel into dentin Break down producing unstable free radicals that react with organic colored pigments within inorganic apatite crystals Smaller and less heavily pigmented molecules are formed that reflect less color - hence creating a whitening effect
