Color and Shade Management in Esthetic Dentistry

Abstract

The color and appearance of teeth is a complex phenomenon, with many factors such as lighting conditions, translucency,
opacity, light scattering, gloss and the human eye and brain influencing the overall perception of tooth color. To achieve
esthetics, four basic determinants are required in sequence; viz., position, contour, texture and color. The knowledge of
the concept of color is essential for achieving good esthetics. This review compiles the various aspects of color, physics
behind perception of color, measurements and shade matching in dentistry for various esthetic treatments.
KEY WORDS: Chroma, colorimeter, hue, shade matching, shade selection, value

Full text

Universal Research Journal of Dentistry · September-December 2013 · Vol 3 · Issue 3120
INTRODUCTION
Think of the world without the color. Color can turn
everything, even the unsightly, into a visual pleasure.
Properly used, color creates atmosphere, defines space
and proportion, establishes order and exudes emotion. To
perceive all these one has to have the so‑called color sense;
i.e., the ability to make the right color choice.
Today’s dental restoration is consolidated around three
mainstays: The use of non‑metallic materials, such
as composite resins and ceramics; adhesion to dental
structures; and the achievement of a natural cosmetic
look.[1] The first step to achieving clinical success in
cosmetic dentistry will therefore be to correctly identify
the tooth color we need to imitate and material that most
closely matches and to communicate this information
to the laboratory if the restoration is to be fabricated
out there.[1]
The color of the tooth is determined by the combined effects
of intrinsic and extrinsic colorations.[2,3] Intrinsic tooth
color is associated with the light scattering and absorption
properties of the enamel and dentine.[2,4] Extrinsic color is
associated with the absorption of materials (e.g., tea, red
wine, chlorhexidine, iron salts) onto the surface of enamel
and in particular the pellicle coating and which ultimately
cause extrinsic stain.[2,5]
Color and Shade Management in Esthetic Dentistry
Vineet S. Agrawal, Sonali Kapoor
Department of Conservative and Endodontics, M.P. Dental College, Hospital and Oral Research Institute, Vadodara, Gujarat, India
The surge of interest in the use of tooth colored restorative
materials and systems in recent years has been attributed
partly to rapid developments in dental materials science
and also to patient demand and operator interest. This has
made several conservative esthetic treatment modalities
available. Although restorative dentistry has been defined
as being a blend of art and science, conservative esthetic
dentistry truly emphasizes the artistic component.
PHYSICS OF COLOR
Sir Isaac Newton was the first to break down the physics
of color. He found that a beam of white light could be
separated into component colors, or wavelengths, by
passing it through a prism. Newton described resulting
continuous series of colors as a spectrum and named these
colors in the following order: Red, orange, yellow, green,
blue, indigo and violet, as represented by commonly used
mnemonicassociationRoyG.Biv.Thesewavelengthsare
perceived by three types of color receptors (called cones)
in the human eye as variations of red, green and blue light,
hence the term visible light spectrum. In physical terms,
the wavelengths of visible light range from approximately
400 to 700 nm.[2,6]
Without light, color does not exist. It is the interaction
of light with the object that allows the perception of
color. If the light interacts with an object, some of the
light is absorbed by an object. The wavelength that are
not absorbed (i.e., those that are reflected, transmitted, or
emitted directly to the eye) are perceived by receptor cells
REVIEW ARTICLE
The color and appearance of teeth is a complex phenomenon, with many factors such as lighting conditions, translucency,
opacity, light scattering, gloss and the human eye and brain inuencing the overall perception of tooth color. To achieve
esthetics, four basic determinants are required in sequence; viz., position, contour, texture and color. The knowledge of
the concept of color is essential for achieving good esthetics. This review compiles the various aspects of color, physics
behind perception of color, measurements and shade matching in dentistry for various esthetic treatments.
KEY WORDS: Chroma, colorimeter, hue, shade matching, shade selection, value
ABSTRACT
Access this article online
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Website:
www.urjd.org
DOI:
10.4103/2249-9725.123975
Address for Correspondence:
Dr. Vineet S. Agrawal,
101, Vinay Complex, Near Dudhdhara Dairy, Bholav,
Bharuch ‑ 392 002, Gujarat, India.
E‑mail: vineetdent@yahoo.co.in
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Agrawal and Kapoor: Color and shade in esthetic dentistry
121Universal Research Journal of Dentistry · September-December 2013 · Vol 3 · Issue 3
depends on the object’s capacity to modify the color of the
incident light. Color appears because the material absorbs
the radiating visible light, with the exception of the
wavelength reflected to the viewer’s eyes. A transparent
medium will allow visible light to pass through almost
unaltered. Translucent object scatter, transmit and absorb
portions of wavelengths of visible light, while opaque
materials do not transmit, but reflect and absorb various
wavelengths of visible light.
The observer
Visible light enters the eye through the transparent area
of the cornea and is focused by the crystalline lens on the
retina. The retina is composed of two types of specialized
photosensitive cells and is the receptor system for vision.
These specialized receptor cells are called rods and cones
and they contain photosensitive pigments.[7]
THREE DIMENSIONS OF COLOR
Color is usually described according to the Munsell color
space in terms of hue, value and chroma. When color is
determined using the Munsell system, value is determined
first followed by chroma. Hue is determined last by
matching with shade tabs of the value and chroma already
determined[10] [Figure 2].
Hue
“Hue” is the quality that distinguishes one family of
color from another. It is specified as the dominant range
of wavelengths in the visible spectrum that yields the
perceived color, even though the exact wavelength of the
perceived color may not be present.[11]
Value
Value is defined as the relative lightness or darkness of
a color or the brightness of the object. The brightness of
any object is a direct consequence of the amount of light
energy the object reflects or transmits. Munsell described
the value as a white‑to‑black gray scale. Bright objects
have lower amounts of gray and low‑value objects have
larger amounts of gray and will appear darker.[12]
(i.e., rods and cones) in the eye and recognized by the
brain as specific color.[7]
PRIMARY PREREQUISITE FOR PERCEPTION
OF COLOR(COLOR TRIAD)
The primary prerequisites for color perception include
three variable elements: The object, a light source for
illumination and an observer [Figure 1].
Light source
Color perception depends on the quality of light illuminating
the object. The ideal light source is natural light, occurring
around mid‑day for accurate color comparison. The time of
the day, month and weather conditions affect the color of
sunlight. If the light source changes, then the light reflected
from an object changes too; in that case, a different color
is perceived. The absence of ideal conditions has led to
the use of artificial lighting for color matching. The light
source that approximates standard daylight is ideal for
shade matching. Color temperature, spectral reflectance
curves and color rendering index (CRI) are all used to
measure the capacity to reproduce standard daylight (CRI
over 90 is recommended for color matching).[8,9] Dental
unit lights are usually incandescent lights that emit light
high in the red–yellow spectrum and are low at the blue
end. Regular cool white fluorescent lights are high in
the green–yellow spectrum. Color‑corrected fluorescent
lights are also available, which render the color more
accurately.[8] Full‑spectrum light‑emitting diodes (LEDs)
are now replacing incandescent bulbs. The shade‑matching
ability is better with a light‑correcting source than under
natural light.[2]
The object
Color is a physical property of the light that is modified
by the object and the total appearance of the material
Figure 1: Color triad Figure 2: Three dimensions of color
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Agrawal and Kapoor: Color and shade in esthetic dentistry
Universal Research Journal of Dentistry · September-December 2013 · Vol 3 · Issue 3122
Chroma
Chroma is defined as the saturation, intensity or strength
of hue. Envision placing red food dye into a glass of
water. Each time more of the same color dye is added, the
intensity increases, but it is the same red color (hue). As
more dye is added, the mixture also appears darker, so the
increase in chroma has a corresponding change in value.
As chroma is increased, the value is decreased; chroma
and value are inversely related.[10,12]
COLOR IN DENTISTRY
Color perception and reproduction processes can be
applied in dentistry, specifically to shade matching
techniques. The important concept includes pigment
colors and the dimensions of color.
PIGMENT COLORS
Pigment colors are inherent hues of an object. Because
these colors are perceived through either transmission
or reflection of light, they are same as the subtractive
color used in color reproduction for reflective and
transmissive media. In dentistry it is necessary to
understand pigment colors as they are inherent in
restorative materials (e.g., ceramic, composites and
acrylic resins).
Primary colors: Red, yellow, blue
The primary pigment colors are similar to subtractive
primaries, but they are referred to as red, yellow and blue,
rather than magenta, yellow and cyan, respectively.
Like subtractive primaries these are the colors that are
perceivedwhenoneoftheRGB,wavelengthsisabsorbed;
red is perceived when green is absorbed, yellow when blue
is absorbed and blue when red is absorbed.
Secondary colors: Orange, green, violet
Secondary colors are formed by combining two of the
primary colors: Red and yellow create orange, yellow and
blue create green, blue and red create violet.
Complementary colors
Complementary colors are those that, when combined
in equal proportions, will form a dull gray that absorbs
and reflects/transmits all wavelength in equal amounts.
Complementary pigment color pairs are blue/orange,
red/green and yellow/violet.
Additive principle of complementary color may be used
to alter the value of restorations; for example, if the value
of a restoration needs to be lowered, the complementary
color can be added to that restoration to make the shade
grayer and hence lower in value.
METAMERISM
Metamerism occurs when the perception of color of two
objects is different because one of the variables of the
color triad (object, light source, or observer) is altered
while the other two remain the same. The phenomenon
of two objects to match in color under one condition but
showing apparent differences under another is termed
metamerism.[13] There are two types of metamerism:
Object metamerism and observer metamerism.
Object metamerism occurs when the two items appear
the same in one lighting condition, but appear differently
when the light source is changed. In dental terms, it occurs
when crown is matched to the natural dentition under
incandescent light, but, when viewed under color‑corrected
or fluorescent light, appears not to match the natural
teeth. To prevent metamerism, objects should have the
same spectral reflectance curves, since only materials with
identical spectral energy distribution curves will match
under all light sources. Color match does not require the light
source and objects to have the same reflectance spectrum.
Therefore, to obtain an acceptable shade determination,
it is advisable for the viewer (technician, clinician and
assistant) to observe the color matching under three
different lighting conditions – daylight, color – corrected
light and dim light.[14]
Observer metamerism occurs when the light source
remains the same and the observer changes, caused by
either human visual stimulus or instrumental stimulus.
Since color perception is dependent upon physiological
spectral response sensitivities of the cones in the fovea
and psychological interpretation by the brain, it is
recommended that a third observer (assistant, technician,
friend, or family member) evaluate the selected color prior
to cementation of any final restoration.
MEASUREMENT OF COLOR
Color determination in dentistry can be divided into two
categories:
• Visual
• Instrumental.
Visual technique
A popular system for visual determination of color
is the Munsell color system, the parameters of which
are represented in three dimensions [Figure 3]. Value
(lightness) is determined first by the selection of a tab that
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123Universal Research Journal of Dentistry · September-December 2013 · Vol 3 · Issue 3
most nearly corresponds with the lightness or darkness of
the color.[15] Value ranges from white to black. Chroma is
determined next with tabs that are close to the measured
value but are of increasing saturation of color. Chroma
ranges from achromatic or gray to a highly saturated
color. Hue is determined last by matching with color tabs
of the “value” and “chroma” already determined. Hue is
measured on a scale from 2.5 to 10 in increments of 2.5
for each of the 10 color families (red, R; yellow‑red, YR;
yellow,Y; green‑yellow, GY;green, G; blue‑green,BG;
blue, B; purple‑blue, PB; purple, P; red‑purple, RP).
Visual color determination of a patient’s tooth is the most
frequently applied method in clinical dentistry. However,
visual determination of shade selection has been found to
be unreliable and inconsistent. Visual color assessment is
dependent on the observer’s physiologic and psychologic
responses to radiant energy stimulation. Inconsistencies
may result from uncontrolled factors such as fatigue,
aging, emotions, lighting conditions, previous eye
exposure, object and illuminant position and metamerism.
Paravina[16] evaluated a newly developed visual
shade‑matching apparatus, Shademat visual+ (SV+).
The SV+ apparatus enabled better shade‑matching
results than daylight. Correlated color temperature of the
daylight varied from 4500 to 6800 K, while light intensity
varied from 140 to 1000 lux. In SV+ trials, these values
were constant at the measuring place: 5000 K and 1400
lux. There is a need for a more scientific and consistent
means of shade matching in restorative dentistry.
Instrumental technique
In this system, the color space consists of three coordinates:
L*, a* and b* [Figure 4].[15] The L* refers to the lightness
coordinate and its value ranges from 0 for perfect black to
100 for perfect white. The a* and b* are the chromaticity
coordinates in the red–green axis and yellow–blue axis,
respectively. Positive a* values reflect the red color
range and negative values indicate the green color range.
Similarly, positive b* values indicate the yellow color range
while negative values indicate the blue color range. The
differences in the lightness and chromaticity coordinates
(ΔL*,Δa*,Δb*)asaresultofultravioletlightexposureare
determinedfirstandthetotalcolorchange(ΔE*ab) can be
calculated using the relationship.
∆∆
∆∆
E* Lab
ab =++(
***
)½
222
Instrumental color analysis, on the other hand, offers a
potential advantage over visual color determination because
instrumental readings are objective, can be quantified
and are more rapidly obtained. Spectrophotometers and
colorimeters have been used with modifications in an
attempt to overcome problems with visual shade matching
in dentistry. Photoelectric tristimulus colorimeters have
the potential to remove some of the shortcomings of
the visual method and have been shown to provide accurate
and repeatable measurements; however, they are not
error‑proof. In dentistry, the results of a colorimetric device
can be altered because the standardized illuminating light
emitted from the device may be scattered, absorbed,
transmitted, reflected and even displaced in a sideways
direction as a result of the translucent optical properties
of teeth and dental ceramics.
SHADE TAKING DEVICES
Shade guides
Shade matching tools are called color standards or shade
guides. There are different types of color standards
for dentistry, depending on their purpose and the tissue
for which they are intended. Tooth color standards, color
standards for oral soft‑tissues and color standards for
facial prostheses‑commonly known as dental, gingival
and facial shade guides, respectively ‑ are possible.
Clark introduced a custom shade guide in 1931 based on
visual assessment of human teeth, recorded in Munsell hue,
value and chroma. Acknowledging the deficiencies of the
available guides, Sproull, in the 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. Quality
control issues regarding color mismatches of shade tab and
porcelain batches from the same manufacturer could be
as problematic as mismatches among manufacturers. The
limitations of shade guides are factors that compromise
shade‑matching procedures in dentistry and contribute to the
dissatisfaction of clinicians, technicians and patients. A new
generation of shade guides has been developed to address
these deficiencies. Shofu offered the natural color concept
(NCC)[17] while Vita introduced a 3‑dimensional shade guide
system (Vita 3D‑Master). The NCC[18] system consists of
208 color blends based on 38 basic shades. The manufacturer
purports that these blends are logically arranged in L* a* b*
color space according to Munsell hue, chroma and value. In
addition, the shade guides and veneering material are made
of the same material to avoid the effect of metamerism.
The Vita 3D‑Master shade guide[6] [Figure 5a] features a
systematic colorimetric distribution of 26 shade tabs within
the tooth color space. The manufacturer purports that this
shade guide demonstrates an equidistant distribution in
the color space. The shade guide is organized into five
primary value levels, with a secondary distribution based on
chroma and hue. These value groups are arranged from the
lightest (value level 1) to the darkest (value level 5), left to
right. Intermediate shades can be achieved based on mixing
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Agrawal and Kapoor: Color and shade in esthetic dentistry
Universal Research Journal of Dentistry · September-December 2013 · Vol 3 · Issue 3124
formulas. The manufacturer advocates a three‑step process:
Value is determined first in making a shade determination
and then the chroma and hue are determined. The selection
process is simplified because the number of choices decreases
throughout the procedure. The shade tabs arrangement
in the Vita classical[6] [Figure 5b] is by hue, whereas in the
chromascop guides[6] [Figure 5c], the tabs are arranged in five
clearly discernible value levels. Within each level are tabs that
represent different chromas and hues. The five levels cover
that area of the CIELAB color solid occupied by natural
teeth. The lightest value level has only two chroma steps of a
single hue and the darkest value level has three chroma steps
ofonehue.Groups2,3and4havethreechromalevelsofthe
middle and orange hue and two chroma levels in each hue
shift toward yellow or red. The sequence of shade selection is
value, then chroma, followed by hue.
There are certain principles that should be followed during
shade selection.[13,14,19‑21] These are as follows:
• Patient should be viewed at the eye level so that the
most color‑sensitive part of the retina will be used
• Shadecomparisonshouldbemadeunderdifferentlighting
conditions. Normally, the patient is taken to a window
Figure 3: Munsell color system
and the color is confirmed in natural daylight after initial
selection under incandescent and fluorescent lightening
• Theteethtobematchedshouldbeclean
• Shadecomparison should be madeat the startof  the
patient visit
• Brightlycoloredclothingshouldbedrapedandlipstick
should be removed
• Shade comparison should be made quickly, with the
color samples placed under the lip directly next to the
tooth being matched
• The eye should be rested by focusing on a gray‑blue
surface immediately before a comparison since
this balances all the color sensors of the retina and
re‑sensitizes the eye to the yellow color of the tooth.
Technology based shade matching devices
• Digitalcameras
• Spectrophotometers
• Colorimeters.
Spot measurement (SM) devices measure a small area
on the tooth surface, while complete‑tooth measurement
(CTM) devices measure the entire tooth.[1,7] For SM
Figure 4: CIELAB system
c
Figure 5: Shade guides; (a) Vitapan 3D master shade guide; (b) Vita
lumin shade guide; (c) Chromascop shade guide
b
a
Figure 6: Technological based shade matching devices; (a) Shade
scan; (b) Spectro shade; (c) Vita easy shade; (d) Crystal eye;
(e) Shade eye NCC; (f) Shade vision
d
c
b
f
a
e
c
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125Universal Research Journal of Dentistry · September-December 2013 · Vol 3 · Issue 3
devices, the size or diameter of the optical device aperture
(generally about 3 mm2) will determine how much of the
tooth surface and subsequent shade is measured. Examples
of such SM technologies are the Shofu ShadeEye‑NCC
chroma meter system and the Vita EasyShade system. CTM
systems measure the entire tooth surface and provide a
topographical map of the tooth in one image. Measurement
of the complete surface gives the operator more consistent
and reproducible information about the tooth structure.
Digital cameras
Digital photography, like many of the newer electronic
technologies in the industry, offers significant benefits to
dental practices. The digital camera is extremely efficient
and easy to use. Instead of focusing light on the film to
create a chemical reaction, digital cameras capture images
using charged coupled devices, which contain millions
of microscopically small light‑sensitive elements.[22] The
advantage of this method is that the camera records each of
the three colors at each pixel location. ShadeScan [Figure 6a]
combine digital color analysis with colorimetric analysis,
but SpectroShade [Figure 6b] is the only one that combines
digital color imaging with spectrophotometric analysis.
Spectrophotometers
A spectrophotometer measures and records the amount of
visible radiant energy reflected or transmitted by an object
one wavelength at a time for each value, chroma and hue
present in the entire visible spectrum.[23] There are two basic
optical light settings used in reflectance spectrophotometer
instruments: Illumination at 0 degrees and observation
at 45° (0/45) or illumination at 45° and observation at
0° (45/0). Because of the limited access afforded by the oral
cavity, only the 45/0 option is suitable for clinical use.[23,24]
The SpectroShade (MHT Optic Research, Niederhasli,
Switzerland) is the spectrophotometer developed
for clinical use that combines digital imaging with
spectrophotometric analysis. The unit consists of a
high‑intensity halogen light source that is directed to
the tooth through fiber‑optic bundles and lenses to
uniformly illuminate the field at a 45° angle. The Vita
EasyShade [Figure 6c] is a handheld spectrophotometer for
tooth shade matching. The fiber optic tip is approximately
5 mm in diameter (SM technology) and contains nineteen
1 mm diameter fiber‑optic fibers. A new spectrophotometer
Crystaleye [Figure 6d], is an extremely precise dental
color analysis system, which provides extremely precise
color measurement based on spectral estimation using a
LED light source.
Colorimeters
Filter colorimeters generally use three or four silicon
photodiodes that have spectral correction filters.
These filters act as analog function generators that limit
spectral characteristics of light striking the detector
surface.[6] The filter colorimeters are considered inferior to
scanning devices like spectrophotometers because of the
inability to match the standard observer functions. However,
because of their consistent and rapid sensing nature, these
devices can be used for quality control.[25‑27] The ShadeEye
NCC chroma meter [Figure 6e] is example of tristimulus
colorimeter. The ShadeVision system [Figure 6f] is a
device that combines digital color image technology with
colorimetric filtering technology.
THREE STEP SHADE MATCHING
PROCEDURES
First lightness, then chroma and then hue should be
matched. It is the same order as for Clark’s, Hayashi’s and
Hall’s shade guides as well as in vitapan 3D master.
What is actually needed is to reduce the number of
potentially adequate tabs to between 2 and 4 as quickly
as possible, by choosing tabs from the same or different
groups.
The next step is to choose the closest tab or combination
of appropriate shade tabs.
If there is no perfect match, a lighter and less chromatic tab
should be chosen, because it would be easy to do extrinsic
correction later.
Dentists position
A tooth should be viewed along its normal axis (the line of
sight perpendicular to the surface), using a diffuse light
source.
The dentist’s eye should be at the level of the patient’s
tooth. Regarding shade matching distance, visual acuity
for near vision is to be tested by Ophthalmologist at the
standard reading distance of 25‑33 cm. Viewing distance
should enables a viewing angle of not less than 2°.
Tab placement
The shade tab should be placed parallel to the tooth being
matched and with the same relative edge position. If
possible it should be in the same plane with the tooth‑not
in front of it or it will appear lighter and not behind it or it
will appear darker.
Time length and pauses
The first impression is frequently the best match and
shade matching trials should be limited to 5 s, at a time to
prevent eye fatigue and the recommendation to relax the
eyes by observing a blue card between two trials.
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Agrawal and Kapoor: Color and shade in esthetic dentistry
Universal Research Journal of Dentistry · September-December 2013 · Vol 3 · Issue 3126
PROBLEMS DURING SHADE MATCHING
Color vision problem/color blindness
Most complex and misunderstood area of color sensation
is the detection of radiant energy by the receptors in the
human eye and the interpretation of this visual stimulation
by human brain.
Color blindness is caused by a deficiency in or absence of
one or more of the three types of photosensitive pigments
able to detect red, green and blue.
Different types of color vision confusion exist:
• Achromatism: Complete lack of hue sensitivity
• Dichromatism: Sensitivity to only two primary hues
usually either red or green is not perceived
• Trichromatism: Sensitivity to all three hues with
deficiency or abnormality of one of the three primary
pigments in the retinal cones.
Age
Aging is detrimental to color‑matching abilities because
the cornea and lens of the eye become yellowed with age,
imparting a yellow‑brown bias. This process begins at
age 30, becomes more noticeable at age 50 and has clinical
significance after 60 years of age. After age 60, many people
have significant difficulties in perceiving blues and purples.
Fatigue
Tired eyes cannot perceive color as accurately as alert
eyes. Compromised visual perception is due to systemic,
local or mental fatigue. Successive shade observations
(treating many patients requiring shade assessment during
a single workday) can be primary cause of fatigue.
Emotions
Color can function as a language. For, e.g., many places
in world, red suggest anger, yellow represents joy, blue is
associated with sadness.
It is generally known that emotion can affect papillary
diameter, causing dilation or constriction and this has a
direct effect on color discrimination.
Medications
The abuse of drugs, alcohol and caffeine will affect not
only judgment, but also color perception. Medications
can act on any part of the visual system from the visual
cortex to the retina. Viagra, a drug used to treat erectile
dysfunction, is notorious for causing vision to have a blue
tint. Of special concern for female practitioners are the
side‑effects caused by oral contraceptives, i.e., red‑green
or yellow‑blue discrimination defects. Long use of oral
contraceptives will cause a decrease in color perception of
blues and yellows.
Binocular difference
Binocular difference is the perception difference between
the left and the right eye. To test for binocular difference,
two objects are placed side by side under uniform
illumination. They may appear different, e.g., the one on
right may seem slightly lighter than the one on the left.
Placing shade tabs either above or below (rather than next
to) the tooth to be matched will help to eliminate error
caused by binocular difference.
Environmental influences
The setting in which an object is viewed can influence the
perceived color. The background and surroundings can
affect the saturations and the hues perceived. Patient’s
complexion, make‑up and even reflection from the operatory
equipment and walls can modify the color of the oral
environment and the shade sample, which can influence the
shade determination. Therefore, it is advisable to remove the
patient’s make‑up and utilize a neutral gray background in
the operatory to reduce the influence of surrounding colors
and to prevent an inaccurate shade determination.
CONCLUSIONS
The color and appearance of teeth is a complex phenomenon,
with many factors such as lighting conditions, translucency,
opacity, light scattering, gloss and the human eye and
brain influencing the overall perception of tooth color.
Continued research on the human visual system has given
us greater insight into how color discrimination is affected
by environment and other features such as disease, drugs
and aging. The basic fundamentals of color and light, the
radiation spectrum and the optical characteristics of the object
is to be understood before evaluating and selecting the proper
color shade for the restoration. The measurement of tooth
color is possible through a number of methods including
visual assessment with shade guides, spectrophotometry,
colorimetry and computer analysis of digital images.
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How to cite this article: Agrawal VS, Kapoor S. Color and shade manage-
ment in esthetic dentistry. Univ Res J Dent 2013;3:120-7.
Source of Support: Nil, Conict of Interest: None declared
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