This presentation is about shade matching procedure in fixed denture prostheses.

1. Shade matching in FPD
DR. PARTHA SARATHI ADHYA
2nd year PGT, Dept. of
Prosthodontics and Crown & Bridge
Under the guidance of :-
Prof.(Dr.) Jayanta
Bhattacharyya.(H.O.D)
Prof.(Dr.) Samiran Das.
Dr. Sayan Majumdar.
Prof.(Dr.) Soumitra Ghosh.
Dr. Preeti Goel.

2. CONTENTS
• INTRODUCTION
• Light and colour
• Method of shade matching
• Factors affecting shade matching
• Visual Shade Guide
• Digital Shade Guide.
• Review of literature.

3. INTRODUCTION
• Shade selection is an important procedure to provide patients
with an esthetic restoration that harmoniously blends to the
patient’s existing dentition. There have been a number of
recent technologic and materials advances that offer the
potential to improve colour-matching skills in prosthetic and
restorative dentistry.

4. Light and colour
• Natural white light—daylight—is sunlight reflected back from the sky. It
falls between 380 and 770 nm along the electromagnetic spectrum.
• Is a mixture of component bands containing a continuous contribution
from radiation of each wavelength between these limits. The component
bands produce six different sensations (red, orange, yellow, green, blue,
violet), but there are an infinite number of gradations.
• Object color is dependent on the illuminant in which it is viewed. If
incident light does not contain a particular wavelength segment, the
object cannot reflect it.

5. • Colorants, either pigments or dyes, are responsible for chromatic
reflection of light. The chemical composition of a colorant makes it
selectively absorb more of one part of the visible spectrum than another.
• A phenomenon of light (such as red, brown, pink, or gray) or visual
perception that enables one to differentiate otherwise identical objects.
• The most popular method for describing color is the Munsell system given
in 1905.
• Just as a solid body can be described by three dimensions of physical form
(length, width, and depth), color has three primary attributes that allow it
to be described with the same precision. The three attributes of color in
this system are called Hue, Value, and Chroma.

6.  Hue
• Hue is defined as the particular variety of a color, shade, or tint.
• This refers to the dominant wavelengths present in the spectral
distribution.
• The Hue of an object can be red, green, yellow, and so on, and is
determined by the wavelength of the reflected and/or transmitted light
observed.
• The place of that wavelength (or wavelengths) in the visible range of the
spectrum determines the Hue of the colour. The shorter the wavelength,
the closer the Hue will be to the violet portion of the spectrum; the longer
the wavelength, the closer it will be to the red portion.
• In the Munsell color system, Hues are divided into 10 gradations: yellow,
yellow-red, red, red purple, purple, purple-blue, blue, blue-green, green,
green-yellow

7. • Each gradation is subdivided into 10 groups; for example, red can be
written 1R, 2R, 3R ... 9R, 10R.
• Most natural teeth fall into a range between yellow and yellow-red. In a
study of 95 extracted anterior teeth,
O'Brien et al found that the average
Hue was 1.2 Y for the gingival third,
1.3 Y for the middle third, and 1.4 Y
for the incisal third.
(O'Brien WJ et al: Dent Mater 13:179, 1997)

8.  Chroma
• Chroma is defined as the intensity of a Hue or the saturation or strength of
the Hue.
• Natural teeth are found with Chroma ranges from 0.5 to 4.
 Value
• Value is defined as the relative lightness or darkness of a color or the
brightness of an object.

9. • The brightness of a crown is usually increased in two ways: by lowering
chroma or by increasing the reflectivity of the surface. Lowering value
means less light returns from the illuminated object and the remaining
light is being absorbed or scattered elsewhere.
(Vimal K Sikri. Color: Implications in dentistry. Journal of Conservative
Dentistry;Oct-Dec 2010 ;Vol 13 ; Issue 4)

10.  Translucency
• Translucency is the three-dimensional representation of value.
• Increasing in the translucency of a object means lowering its value
because less light returns to the eye , With increased translucency, light is
able to pass the surface.
• The translucency of enamel varies with the angle of incidence, surface
texture and luster, wavelength and level of dehydration.
(Fondriest J. Shade matching in restorative dentistry; The science and
strategies. Int J Periodontics Restorative Dent 2003;23:467-79)

11. • Highly translucent teeth tend to be lower in value, since they allow light to
transmit through the tooth and pick up the shadows and darkness of the
oral cavity and the surrounding environment.
• More opaque teeth allow less light transmittance; they are more reflective
in nature and, therefore, appear brighter.
• Translucency/value are the most important parameters in shade selection,
since hue is not easily detectable and there is a lack of chroma in the
lighter shades.
(G. Gurel.The Science and Art of Porcelain Laminate Veneers.)

12.  Fluorescence
• Fluorescence is the absorption of light by a material and the spontaneous
emission of light in a longer wavelength.
• In a natural tooth, it primarily occurs in the dentin because of the higher
amount of organic material. UV light is absorbed and fluoresced back as light
primarily in the blue end of the spectrum.
• The more the dentin fluoresces, the lower the chroma.
 Metamerism
• Two colors that appear to match under a given lighting condition but have
different spectral reflectance are called metamers, and the phenomenon is
known as metamerism.
• The problem of metamerism can be avoided by selecting a shade and
confirming it under different lighting conditions, such as natural daylight and
fluorescent light.
(Baltzer A, Jinoian VK. Determination of tooth colors. Quintessenz Zahntech
2004;30:726-40)

13.  Opalescence
• Opalescence is the phenomenon in which a material appears to be of one
colour when light is reflected from it and of another colour when light is
transmitted through it.
• The hydroxyapatite crystals of enamel also act as prisms. Wavelengths of
light have different degrees of translucency through teeth and dental
materials.

14. CIE 1931 system
• In 1931, the CIE introduced a system of instrumental colour measurement
for describing colours. It is based on the fundamental property of
trichromacy.
• There are 3 primary colours which are known as primaries. Theses are red,
green, blue.
• These three colours are in different proportions in any cololurs. The
amount of the three primaries used (ie R, G and B) are known as the
tristimulus values of the colour new colour [C].

15.  Additive color theory
• The additive primary colors are red, green and blue (RGB). Combining one
of these additive primary colors with equal amounts of another one
results in the additive secondary colors of cyan, magenta and yellow.
• The subtractive primary colors are cyan, magenta and yellow Subtractive
color mixing occurs when light is reflected off a surface or is filtered
through a translucent object.

16.  Chromaticity
• As mentioned, colour is three-dimensional, with the three attributes of
colour being hue, lightness and chroma. This means that the CIE system
must be three-dimensional which gives rise to the concept of colour
space.
o L* = 116(Y/Yn)1/3 – 16
o a* = 500[(X/Xn)1/3 – (Y/Yn)1/3]
o b* = 200 [(Y/Yn)1/3 – (Z/Zn)1/3]
• Xn, Yn and Zn are the tristimulus values
for a particular
standard illuminant and standard
observer for a sample reflecting100% of the light at all wavelengths.

17. • In this three-dimensional colour space, lightness is represented by L* on a
scale of 0 for black to 100 for white. The hue and chroma of a sample are
represented on an a* versus b* plot.

18. Method of shade matching
• Remove bright color from the working field. If the patient is wearing bright
clothing, it is prudent to cover the patient with neutral color bib (grey).
Any dark color lipstick should be removed, because it could affect shade
matching.
• Always clean the tooth by using prophylaxis paste prior to shade selection.
• Its important not to view the shade comparision for more than 7 s to avoid
eye fatigue.
• Clinician should be at a distance of 28-33 cm from the patient during
shade selection.

19. • Always determine shade when the teeth are most hydrated, because
enamel dehydration reduces its translucency by 82%, misleading the
clinician.
• Shade comparison should always be done in between 10 am and 2 pm,
because at this time color temperature is around 5500 K and then under
color corrected light to ensure the accuracy of the match.
• During the shade comparison always place shade tabs either above or
below the tooth to be match, never place shade tab adjacent to the tooth
to avoid binocular effect.
• Always, value is analyzed first, followed by chroma and then hue.

20. • Shade selection should not be done immediately after bleaching, patient
should be recalled after 2-3 weeks for shade comparison.
• Always during shade selection teeth should be divided in 3 regions.
Gingival area (gives accurate determination of dentinal chroma), Body
area and Incisal area (enamel is thickest here and varies from translucent
to transparent).

21. Factors affecting shade matching
 1938 issue of the Journal of the California Dental Association, Dr. Charles
Pincus had mentioned 3 factors which essential for shade selection-
1. Direction of light
2. Movement of light
3. Color of light.
 Wagenaar and Smith suggested 3 factors for shade selection
1. How the tooth being is viewed
2. How the light source being used
3. The eyes of the observer.
(Burkinshaw SM. Colour in relation to dentistry: fundamental of colour
science. Br Dent J. 2004;196:33-41.)

23. Light
• Different parameters of light are related to shade selection such as its color
rendering index (CRI), color temperature and its nature.
 Colour rendering index (CRI)
• measure of the ability of a light source to reproduce the colors of various
objects being lit by the source.
• It is rated from 0 to 100. A CRI of 100 gives the best possible rendition of color.
• The average incandescent dental-unit lamp has a CRI of 75.
• A CRI greater than 93 is preferred for shade matching..
 Light intensity
• measured in foot-candles or lumens per foot²

24. • If light intensity is too small, fine details are missed and the eye has
difficulty perceiving hue.
• Too great an intensity decrease the accuracy of color rendering. Dental-
unit lights should not be used for color rendering; they are too bright and
cause glare.
• Glare fatigues the eyes; rendering shades immediately after using a
dental-unit light is also contraindicated.
• The ideal luminosity for dental shade matching is 75 to 250 footcandles.
• To have 175 footcandle intensity at the level of the dental chair, ten to
twelve 4-foot bulbs would be needed in a 10 ft x 10 ft room with 8-foot
ceilings.
(Shade Matching in Restorative Dentistry: The Science and Strategies. James F.
Int J Periodontics Restorative Dent 2003;23:5 466–479.)

25. • The distribution and intensity of sunlight depends on different factors
such as time of the day, relative humidity, environmental pollution,
weather conditions and season of the year.
• light during morning or evening hours is rich in yellow and orange but
lacking in blue and green, with its distribution changing under cloud cover
• sunlight has been standardized for shade selection purposes in the form of
“northern daylight” i.e. sunlight around the noon hour on a bright day
with slight overcast.
(Dagg H, O’Connell B, Claffey N, Byrne D, Gorman C. The influence of some
different factors on the accuracy of shade selection. J Oral Rehabil.
2004;22:900-04.)

26.  Colour temperature
• Color temperature is the mean wavelength of the ambient light.
• Light at this temperature can be described as having a medium-
temperature feel and is considered “white” light.
• dental-unit lamp has a temperature of averages 3,800 K.
• Ideal temperature needed for shade selection is 5000k.
• For shade selection CIE standard D65, D50, D55 lights can be used.

27. View of the object
• Surfaces perpendicular to the viewer send the most light back. The
reflective surfaces of a tooth will not return as much light to the eyes if
they are not perpendicular to them.
• Reflection from a smooth, mirror- like surface results in a clear, well
defined image. Such a “specular reflection” returns a high percentage of
direct, non diffused light, and if strongly illuminated, will be brighter and
stand out.
• Smoothing the texture of the buccal surface will make teeth appear lighter
and brighter and is therefore a primary determinant of value.

28. The eyes of the observer
 Role of cone cells
• Humans have three types of cone-shaped receptor cells, each sensitive to
one of the three primary colors of light (red, green, and blue).
• Impulses from the three types of receptor cones are combine into a coded
signal prior to transmission from the eye.
• The combination takes place in the ganglion cells in the retina.

29. • The eye cannot distinguish the component wavelengths in a color sample.
• Two lights of different colors when mixed produce a third color, and no human
eye can detect its composite nature.
• Ultimately, the perceived hue is the dominant or average wavelength.
 Afterimage and visual distortion
• Afterimages are frequent physiologic effects of the cone receptors with
normal function that cause alterations in perceptions.
• Afterimage that commonly affects clinicians is the spreading effect that occurs
when light is removed from the retina; the receptors continue for a short time
to be active and send a signal to the brain.
• If presented simultaneously with two adjacent areas of different color, the
eyes will flick back and forth between them involuntarily. The color seen for
each is a combination of the true color of the area and the afterimage of the
adjacent area.

30. • Strong red lipstick next to the tooth being evaluated will fatigue the red
receptors in the roaming eyes, while the blue and green receptors remain
fresh and can be fully stimulated. This can yield a perception of the tooth
that is too blue-green.
• An 18% reflective gray colour is an excellent background for evaluation of
hue and chroma. It has no complementary colors (thus, no afterimages are
produced), and it is bright enough to limit the contrast of brightness
between the teeth and background.
(Pensler AV. Photography in the dental practice. Quintessence Dent Technol
1983;14:855–858.)

31.  Binocular Difference in Color
• Perception Binocular difference is a perception variance between the right
eye and the left eye. Such color perception disparity between the eyes of
an individual is small; however, when it is present, there must be a
compensation for it. When two objects of the same shape and color are
juxtaposed (arranged side by side), they may appear to be different (i.e.
one seems to be slightly lighter than the other)

32. • Binocular color differences cause disharmony in shade selection and color
matching. Placing shade tabs on the same side of the tooth to be matched
will help to eliminate error and compensate for this effect .

33. VITA classical
• The VITA classical shade family is divided into the following categories.
• A1 . A2 . A3 . A3,5 . A4- hue= Reddish-brownish.
• B1 . B2 . B3 . B4- hue = reddish-yellowish
• C1 . C2 . C3 . C4- hue = grayish
• D2 . D3 . D4- hue = reddish-grayish
• B1, A1, B2, D2, A2, C1, C2, D4, A3, D3, B3, A3.5, B4, C3, A4, C4 – according
to value.

34. VITAPAN
3D-Master Shade System
• Introduced in 1998.
• According to the manufacturer, this shade system provides a systematic
arrangement of ‘‘virtually all existing natural tooth shades,’’ and it has
been determined that the order of color dimensions in this guide is
adequate.

35. • Based on spectrophotometric measurements of natural teeth, the shade
guide is organized so that it covers the three-dimensional natural tooth
color space in logical, visually equidistant order. Rather than grouping the
shades by Hue, as in the Vita Classical.
• Each set shows a single value, 1 being the lightest (high value) and 5 being
darkest (low value).

36. • The five levels cover that area of the CIELAB color solid occupied by
natural teeth, with approximately 50% of natural tooth shades occupying
the middle value level. 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. About 2% of natural teeth occupy these outer levels.
• In each of the groups, Chroma increases from top to bottom (1 being least
chromatic and 3 being most chromatic).

37. • All the group except 1 and 5; have 3 letters: L, M, R which allow hue to be
chosen (L is yellow hue; M is yellow-red and R is red hue)
• Recently, Vitapan 3D-Master was modified with the introduction of 6
groups in it. No. 0 for the shade matching of bleached teeth
(Advances in color matching. Jane D. Brewer. Dent Clin N Am 48 (2004) 341–
358)

38. VITA Linearguide 3D-MASTER
• Instead of 3 step matching process this include 2 step mating process.
• The VITA Valueguide 3D-MASTER, which is located on top, contains 6
shade samples of the lightness levels 0 – 5.
• The 5 VITA Chroma / Hueguides 3D-MASTER positioned vertically in the
lower part of the acrylic box contain the 29 shade samples as found in the
VITA SYSTEM 3D-MASTER.
1. Lightness level 0/1: 0M1, 0M2, 0M3, 1M1, 1M2.
2. Lightness level 2: 2M1, 2L1.5, 2R1.5, 2M2, 2L2.5, 2R2.5, 2M3
3. Lightness level 3: 3M1, 3L1.5, 3R1.5, 3M2, 3L2.5, 3R2.5, 3M3

39. • Lightness level 4: 4M1, 4L1.5, 4R1.5, 4M2, 4L2.5, 4R2.5, 4M3.
• Lightness level 5: 5M1, 5M2, 5M3.

40. Digital Shade Guide
• There are 2 basic types of devices used for shade selection
 Colorimeters
• These were the first type of colour measuring instrument and, in essence,
attempted to copy the human visual process by using three (or sometimes
four) light filters.
• ΔE = [(L2 – L1)² + (a2* – a1*)² + (b2* – b1*)²]
• Based on technology, colorimeters can be of two types.
• Photoelectric tri stimulus colorimeters
• Silicon photodiode array

41. • In the first type of apparatus, dyed polymer optical filters are being used –
each corresponding to one of the primary colors – are deposited on the
top of the photo detector cells in a specific pattern.
• Each photo detector will then produce an output signal that is determined
by the transmittance characteristics of the overlying optical filter.
• This construction allows the intensity of each primary color component of
the incident light to be measured. The information provided by three
photo detectors (one specifically registering tristimulus value x, y, z each)
enables the position of the incident light’s color to be plotted within the
color triangle.
• The second type has an integrated trans impedance amplifier that
provides a low impedance voltage source and widens the dynamic range
of output signal.

42. • This facility enables the output signal to be monitored by either 4 –
channel chart recorder or on the screen of an oscilloscope.
 ShadeEye
• It consists of two components - a main unit that includes an integrated
printer and a mobile measuring unit.
• The mobile wireless measuring unit analyses the tooth shade digitally and
instantly transmits the information to the main unit through an infrared
interface.
• The technique involves the placing of a disposable contact tip in the 1st in
the gingival one-third of the tooth and then subsequently middle third and
incisal a color and shade map of the tooth is generated.

43.  Shade Vision
• Shade-X (X-Rite, Grandville, MI) is basically imaging colorimeter, which is
commonly used in the professional settings. This device blends
colorimeters filtering technology with a digital colour image.
• It uses three different databases (gingival, medial and incisal third) for the
complete tooth image. Practical testing of colour reproduction during
fabrication can be performed with the aid of virtual try in.

44.  Shofu's Shade NCC Chroma Meter
• Shofu's Shade NCC (Natural Colour Concept) Chroma Meter (Shofu's
Dental, Menlo Park, California) was introduced in the late 1990s. It is an
example of tristimulus colorimeter. It is made up of hand held probe of 3
mm in diameter. In the database of Shofu's Shade NCC Chroma Meter,
porcelain samples are stored in memory.

45.  Spectrophotometer
• spectrophotometer is a device that measures the spectral reflectance of a
body by accessing light intensity.
• Spectrophotometers differ from spectroradiometers primarily because
they include a stable light source.
• There are two types of basic designs commonly used for these
instruments. The traditional scanning instrument consists of a single
photodiode detector that records the amount of light at each wavelength.
The light is divided into small wavelength intervals by passing through a
mono chromator.

46. • A more recent design uses a diode array with a dedicated element for each
wavelength. This design allows for the simultaneous integration of all
wavelengths. Both designs are considerably slower than filter colorimeters but
remain the tools that are required to examine and develop accurate color-
measuring devices.
(Shade Matching in Aesthetic Dentistry – From Past to Recent Advances. Smitha
AJ, Savitha PN. Journal of Dentistry and Oral Care Medicine. Volume 3 .Issue 1)
 The Vita Easyshade
• It is a hand-held spectrophotometer that consists of a handpiece connected to
a base unit by a monocoil fiberoptic cable assembly.
• The contact probe tip is approximately 5 mm in diameter. It contains 19 .1-
mm-diameter fiberoptic bundles. During the measurement process, the tooth
is illuminated by the periphery of the tip, directing the light from a halogen
bulb in the base unit into the tooth surface.

47. • A combination of various filters and photodiode arrays receive the light as
it is directed through the return fibers located in the center of the probe
tip. Through this arrangement, spectral reflectance of the scattered light is
essentially measured in 25 nm bandwidths.

48. Shade selection for resin-bonded fixed partial
dentures
• shade selection for the pontic can be quite difficult, because the shade of
the abutment changes when the metal framework is seated.
• The shade difference is mainly seen in anterior teeth region where where
there is a change in the translucency.
• Try-in the metal framework and check for fit.

49. • Select a resin cement for bonding.
• For powder/liquid cements, mix the powder with glycerin instead of the
liquid to produce a simulated try-in cement. For 2-paste cements, select
the more opaque paste.
• Try-in the metal framework on the abutments using the simulated
cement. Modify the opacity of the simulation cement until the desired
translucency is achieved for the abutments and the pontic.
(Shade selection for resin-bonded fixed partial dentures. Yuuji Sato , Takayasu
Kubo. J Prosthet Dent 2000;83:528-9.)

50.  An Evaluation of Shade Differences Between Natural Anterior Teeth in
Different Age Groups and Gender Using Commercially Available Shade
Guides.
 Shobha Rodrigues ,S. Ramanand Shetty ,D. R. Prithviraj.
 J Indian Prosthodont Soc (Oct-Dec 2012) 12(4):222–230.
 The aim of the study is to determine
o To determine the most suitable shade for the maxillary central incisor of
different age groups.
o To determine the most suitable shade for the mandibular central incisors
of different age groups.
o To analyze shade variation with age and gender.

51.  Male and female subjects are categorized in four age groups: 15–25, 25–
35, 35–45 and 45 years above
 Used shade guides i.e. Vita Lumin (Vita Zahnfabrik, Bad Sackingen,
Germany), Chromascop (Ivoclar, Vivadent, UK) including the Vita 3D
Master (Vita Zahnfabrik, Bad Sackingen, Germany) .

52. • The results also suggest that mandibular teeth are lighter as compared to
the maxillary teeth. With the Vita Lumina shade guide 87.75 % of the
subjects had lighter mandibular incisors as compared with the upper,
89.50 % had lighter mandibular incisors with Vita 3D Master and 87 % had
lighter mandibular incisors with the Chromascop shade guide.
• Although generally males had darker teeth as compared to females.

53.  A comparison of conventional visual and spectrophotometric shade taken
by dental professionals.
 IF Alshiddi, LC Richards.
 Australian Dental Journal 2015; 60: 176–181
 The aim of this study was to compare the accuracy of shade selection
using a spectrophotometer with a conventional method using a shade
guide for observer.
 Nine dental professionals participated in this experimental study. Each
professional matched the shade of middle third of maxillary right central
incisor for eight test subjects using both methods.( VITAPAN- 3D,
EASYSHADE)

54. • A SpectroShade reflectance spectrophotometer was used to access colour
difference and difference in lightness in EasyShade and vitapan-3 master.
• The overall results showed that the Vita Easyshade spectrophotometer
was more accurate for shade matching than the visual method. Overall,
the average ΔE for the spectrophotometric method for all operators (was
3.6 compared with 4.2 for the visual method.

55. CONCLUSION
• Each individual perceive color differently ,the knowledge and skill of each
practitioner always play a significant role. There are several factors that
can influence the clinicians’ color assessment. Technology based system
provides an accurate shade selection and natural looking restoration.

56. REFFERECES
• O'Brien WJ et al: Dent Mater 13:179, 1997
• Vimal K Sikri. Color: Implications in dentistry. Journal of Conservative
Dentistry;Oct-Dec 2010 ;Vol 13 ; Issue 4
• Fondriest J. Shade matching in restorative dentistry; The science and
strategies. Int J Periodontics Restorative Dent 2003;23:467-79
• G. Gurel.The Science and Art of Porcelain Laminate Veneers.)
• Burkinshaw SM. Colour in relation to dentistry: fundamental of colour
science. Br Dent J. 2004;196:33-41
• Shade Matching in Restorative Dentistry: The Science and Strategies.
James F. Int J Periodontics Restorative Dent 2003;23:5 466–479

57. • Shade Matching in Restorative Dentistry: The Science and Strategies.
James F. Int J Periodontics Restorative Dent 2003;23:5 466–479
• Dagg H, O’Connell B, Claffey N, Byrne D, Gorman C. The influence of some
different factors on the accuracy of shade selection. J Oral Rehabil.
2004;22:900-04
• Pensler AV. Photography in the dental practice. Quintessence Dent Technol
1983;14:855–858
• Advances in color matching. Jane D. Brewer. Dent Clin N Am 48 (2004)
341–358
• Baltzer A, Jinoian VK. Determination of tooth colors. Quintessenz Zahntech
2004;30:726-40

58. • A comparison of conventional visual and spectrophotometric shade taking
by trained obsevers. IF Alshiddi, LC Richards. Australian Dental Journal
2015; 60: 176–181
• An Evaluation of Shade Differences Between Natural Anterior Teeth in
Different Age Groups and Gender Using Commercially Available Shade
Guides. Shobha Rodrigues ,S. Ramanand Shetty ,D. R. Prithviraj. J Indian
Prosthodont Soc (Oct-Dec 2012) 12(4):222–230.