Color in fixed prosthodontics

By Dr.Swathi Pai on Tuesday, December 9, 2008 with 0 comments

Hue: the name of the color (red, blue, green, etc.)

Hue order: violet, blue, green, yellow, orange, red (380-760nm)

Value: the whiteness or blackness of a color

  • a low value is closer to black and a high value is closer to white

Chroma: the saturation or intensity of the hue

Munsell color system: recognized the basic color ordering system---a 3-D sphere of hue, value, & chroma

The 10 hue in order: red, yellow-red, yellow, green-yellow, green, blue-green, blue, purple-blue, purple, red-purple

The additive color system:

  • the primary colors of this system: red, green, & blue
  • mixing of the 3 primary colors in this system gives white
  • the secondary colors of this system: magenta or violet (red + blue)
  • yellow (red + green)
  • cyan (blue + green)
  • Complimentary colors: the addition of a primary and secondary color gives white

The subtractive color system:

  • the primary colors of this system: cyan, magenta, & yellow
  • mixing of the 3 subtractive colors in this system gives black
  • the secondary colors of this system: red, green, & blue

The partitive color system (aspects of both the primary and secondary systems)

  • here, insert orange to replace cyan
  • the primary colors in this system are red, green, blue, & yellow
  • The complimentary colors of the modified subtractive color system wheel:
  • red----green
  • orange----blue
  • yellow----violet
  • transparent: allows the transmission of all light
  • translucent: allows transmission of light, but one cannot see through the object
  • spectral reflectance: reflection without diffusion (surface reflection of light without diffusion.
  • Metamerism: a phenomenon that occurs when 2 objects match in color under certain lighting conditions, but do not match under others. This occurs when objects have different spectral curves
  • rods of retina: responsible for interpreting brightness differences. Used for vision at low light levels.
  • cones of retina: mediators of color vision
  • the act of squinting reduces the light on the retina, activates the rods and discriminates value differences
  • the easiest modification with color: raising the chroma (add yellow, brown, or red)
  • yellow = vita B, brown = vita A, and red = vita D
  • Hue shift: to move yellow toward orange, add pink
  • Adding yellow decreases redness of an orange hue
  • A more difficult modification: reducing the chroma---utilize this with the complimentary color: ex: yellow---add violet orange---add blue
  • To reduce the value, add the complimentary color or brown
  • A very difficult procedure: raising the value---yellow is the only color that will change the hue, increase chroma, & raise the value.
  • To create apparent translucency, blue is the key hue

Category: Prosthodontics Notes



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