Color and Perception

Value - Chroma - Hue

Chronology of determining color.

Hue

The dominant color of the object, distinguishing one family color from another.

A

(Hue) Reddish brown.

B

(Hue) Reddish yellow.

C

(Hue) Grey.

D

(Hue) Reddish grey.

Value

The lightness of color. Amount of light returned from an object.

Value

The WHITE-TO-BLACK GRAY SCALE (light to dark).

Chroma

INTENSITY of the color in a scale of 1-10 (10 is saturated).

1-3

The tooth has how many chroma?

Decreased

As chroma is increased, the value is?

Increased

HIGHER numbers on the Vita Classic Shade Guide _________ chroma.

Clark (1931)

Introduced a CUSTOM shade guide based on VISUAL ASSESSMENT of human teeth, recorded in MUNSELL HUE, VALUE, AND CHROMA.

Sproul (Early 70s)

Suggested that an ideal shade guide should consist of SHADE (COLOR) TABS that are WELL DISTRIBUTED AND LOGICALLY ARRANGED in color space, preferably based on the MUNSELL COLOR SYSTEM.

Miller (Mid 90s)

Acknowledged that the MATERIAL of the shade guide should be the SAME AS THE RESTORATION.

Vita Classical Shade Guide

Based on the hue, 16 TABS are arranged into FOUR GROUPS and within the groups corresponding to the chroma.

Vita 3D Master

Since there are some LIMITATIONS with Vita Classical Shade Guide, this shade guide is the most commonly used among the commercially available shade tabs.

Vita 3D Master

A systematic colorimetric distribution of 26 SHADE TABS within the tooth color space.

Vita 3D Master

The shade guide is organized into FIVE PRIMARY VALUE LEVELS, with a SECONDARY DISTRIBUTION based on chroma and hue.

Chromascop

It uses a NUMBERING SYSTEM to identify shades. It is organized into groups depending on the hue.

Natural Color Concept (Shofu)

This system consists of 208 COLOR BLENDS based on 38 BASIC SHADES. The manufacturer claims that these blends are LOGICALLY ARRANGED in LAB COLOR SPACE according to MUNSELL HUE, CHROMA, AND VALUE.

Natural Color Concept (Shofu)

The shade guides and veneering material are made of the SAME MATERIAL to avoid the effect of METAMERISM.

Composite Resin - Ceramic - Acrylic

Used to fabricate custom-made shade guides.

Aluminum Oxide

Shade guide modifications can be performed using SURFACE COLORANTS or by SURFACE ABRASION using?

Ceramic

Dentin system can be used for the fabrication of TRANSLUCENT ALL _______ crowns and veneers.

Dentin and Extended Shade Guides

This shade guide helps in communicating a SPECIFIC SHADE to the dental laboratory.

Colorimeter

Measures color (hue, chroma, and value) AS PERCEIVED BY A HUMAN EYE.

Colorimeter

It can only measure color by measuring TRISTIMULUS VALUES under FIXED ILLUMINATION AND OBSERVER CONDITIONS.

Colorimeter

KEY OPTICAL ELEMENTS: The light source, integrating sphere, and detector (three or four filters).

Tristimulus Values

(Colorimeter) The three results are expressed as X, Y, and Z, respectively and are called?

Spectrophotometer

Commonly used to ANALYZE SURFACE COLORS.

Spectrophotometer

They measure the amount of SPECTRAL REFLECTION from the body.

Spectrophotometer

It is a photometer that can measure INTENSITY based on color, or more specifically, WAVELENGTH.

Digital Cameras

The MOST BASIC FORM of an electronic shade matching device.

Digital Cameras

In contrast to film cameras, this device records images using CHARGE-COUPLED DEVICES (CCDS) which comprise PHOTOSITES.

Digital Cameras

It provides a THOROUGH AND PRECISE picture of the tooth surface and is also useful for COLOR MAPPING.

Digital Cameras

There is a FLASHCARD that records ALL MEMORIES and allows the recording of VOICE FEEDBACK that can be SENT DIRECTLY to the lab without the need for a computer.

Hybrid Devices

Provides a combination of DIGITAL IMAGING AND SPECTROPHOTOMETRIC analysis.

Hybrid Devices

It uses CLEARMATCH software system (Hood River, OR: Smart Technology) and is a HARDWARE INDEPENDENT product.

Color Rendering Index (CRI)

Its value indicates HOW GOOD A LIGHT SOURCE (for example LED lighting) is able to show the real color of an object.

100

Maximum CRI value.

Whiter

The tooth should be MOIST WITH SALIVA as dehydration results in a ______ APPEARANCE.

Squint Test

It is performed by bringing the EYELIDS CLOSER and then looking at the shade guide and the natural tooth.

Translucency

Dehydration of teeth decreases?