MEASUREMENT OF COLOR
Karthikeya Vishwanath
210301030
CONTENT
• Introduction
• There dimensions of Color
• Measurement of Color Parameters
• Factors Affecting Color Matching
• Color Matching of Restorations with Tooth
• Problems of Color Matching
• Research paper
• Conclusion
• Bibliography
INTRODUCTION
• The most important goal of dentistry is to
restore or improve aesthetics the color and
appearance of natural dentition
• Light is a electromagnetic radiation that
can be detected by human eye
• The Human eye is sensitive to wavelengths
from 400nm(violet) to 700nm(dark red)
• The electromagnetic radiation in the visible
region interacts through reflection,
absorption, refraction or transmission
• These phenomena determine the opacity ,
translucency or transparency of an object
THREE DIMENSIONS OF COLOR
HUE
The dominant color of an object
example red, green and blue.
This refers to the dominant
wavelengths present in the spectral
distribution.
These sequence of different colors
creates 3D color solid as shown in the
figure
Value(Grey Scale)
It is the vertical or Z-axis of the 3
Dimensions of the color space
Its is also expressed as the L Factor
or the Lightness factor
Value identifies the lightness or
darkness of a color for a light
diffusing and a light reflecting
surface like a tooth or dental crown
Chroma
It is the degree of saturation of a dominant
color of an object or a particular HUE
Example- Red can vary from pink to scarlet
where pink has low saturation and scarlet
has high saturation
Higher the chroma more intense the color
Chroma is always associated with hue and
value of dental tissue, restorations and
prostheses
MEASUREMENT OF COLOR PARAMETERS
Munsell’s Color System
• It is a color space that specifies colors based on
three properties of color: hue (basic color),
chroma (color intensity), and value (lightness)
• The system consists of three independent
properties of color which can be represented
cylindrically in three dimensions as an irregular
color solid
• hue, measured by degrees around horizontal
circles
• chroma, measured radially outward from the
neutral (gray) vertical axis
• value, measured vertically on the core cylinder
from 0 (black) to 10 (white)
Other Techniques
Colorimeters Spectrophotometer Chromaticity Diagrams
FACTORS AFFECTING COLOR
MATCHING
Sources of Illumination
Incandescent lamp , fluorescent and white
light vary with brightness of emitted light
Surrounding reflectors, wall paints of
clinics ,color of patients dress, cosmetics like
lipsticks
Nature of the Object
• Transmission , scattering and absorption of colors
• Reflections-black surface absorbs all colors ,
colored surfaces absorbs all other colors and
reflects their own color
• Metamerism - Certain Colors match properly in
one source and mismatch in others
• Isomerism –Exact matching of any 2 shades at all
sources or colors
• Surface gloss or roughness: Glossy surface reflects
more light
Observers Physiological Aspects
• The human eye is almost equally sensitive to all
colors but has higher response to green
• Color blindness: Cone cell abnormalities or
deficiencies make one or two color detection
ineffective
• Color fatigue: When nerve ends are continuously
exposed to intense color , the intensity appears to
decrease .If that color suddenly vanish, its
complementary color may be perceived by fatigue
• Background or surrounding color influence the
perception
COLOR MATCHING
• Color matching is the most often performed with the
use of shade guide to select the color of ceramics,
veneers, inlays or crowns
• The hue, value, and chroma of patients , teeth should
exactly match with those of selected materials and
fabrication
• The individual shade tabs shown in the figureare
grouped according to hue:
A = Red-brown
B = Red-yellow
C = Gray
D = Red-gray
Followed by value (1 to 4 or lightest to darkest)
PROBLEMS OF COLOR MATCHING
• The hue, value and chroma of teeth depends on:
1.Patients Age and gender
2.Oral health conditions like discoloration of the teeth
3.Placement and position of teeth
4.Nature of light intensity, wavelength
• Due to these optical anomalies it is impossible to select a perfect color
matching materials
RESEARCH PAPER
OBJECTIVES
To review current status of hand held
systems for too color matching in vivo and
corresponding research
Methods
• Visual Method
• Spectrophotometer
• Colorimeter
• Digital Camera and Imaging systems
• Complete tooth surface Measuring devices
RESULT
• Complete tooth surface and limited area tooth surface measurement
devices exist and either measure the complete tooth surface providing a
‘‘color map’’ or a smaller diameter [3–5 mm] on the tooth surface,
respectively
• Both instrumental and visual color matching method should be used, as they
complement each other and can lead towards predictable aesthetic
outcome
CONCLUSION
• The development of a general purpose, technique insensitive, direct filling,
tooth colored, color stable restorative materials remain the most serious
challenges of current dental materials research Since esthetic dentistry
imposes severe demands on artistic abilities of the dentist and technician,
knowledge of underlying scientific principles in measurement of color is
essential
BIBLIOGRAPHY
• Phillis’s Science of dental Materials Second South Asia Edition
• Science of Dental Materials with Clinical Applications V Shama Bhat
• Researchgate.net
• https://en.m.wikipedia.org/wiki/Munsell_color_system
THANK YOU……
