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The shade-matching tools that mostdental practitioners use to identifyand communicate color and shade

information with others are called colorreference standards or, simply, shade guides.Presently, dentists use shade guides fordescribing tooth shades, prepared teeth(dentin/stump guides), gingival tissues,and even human skin.

BRIEF HISTORICAL BACKGROUNDHue-Based and Value-Based

Shade GuidesTooth shade guides were first developed inthe late 1920s in response to the acceptanceof Munsell’s color theory1 and the develop-ment of dental ceramics intended for artifi-cial porcelain teeth and customized dentalrestorations. The individual shade tabs ofthose early guides were empirically devel-oped, based on the availability and popular-ity of commercially available porcelainshades. The best-known and most popularguide worldwide is the VITA ClassicalShade Guide (Figure 1). Introduced in 1927,this guide is still manufactured by VITAZahnfabrik in Bad Säckingen, Germany.Surprisingly, the manufacturer never used alogical arrangement, systematic, or scientif-ic approach based on range of known hu -man tooth shades to develop this guide. Infact, the 16 shades of the VITA Classic ShadeGuide have been reported to cover only 6%of the color range of human teeth.2 Anyonewho has ever struggled to find a match toone of those 16 tabs can attest to this limita-tion. The Vitapan 3D Master Guide (VITA),which was introduced in 1998, has 26shades and has been systematically ar -ranged and designed to address some short-comings of earlier guides (Figure 2). It has asuperior range of coverage but still on lyapproximates 25% of tooth color range.3According to Paravina et al,4 the actual cov-erage for each guide is somewhat higher,and when the range of the 2 shade guidesare combined, can be as high as 52%. Otherpopular guides fall somewhat in betweenthe range of these 2 guides. In addition to having a limited shade

range, the vast majority of tooth shade

guides are hue-based and not value-based. Val -ue represents the optical brightness (orluminosity) of the color, according to Mun -sell.1 Detecting the value of objects is thefunction of the rod cells, one of the 2 mainphotoreceptors of the eye. The cone cells,which are sensitive to color, are the other.There are approximately 120 million rodcells and 6 to 7 million cones in the humaneye. Comparing the relative number of rodsto cones means that humans are incrediblymore sensitive to the value of an object thanits hue. Even small differences between thevalue of a restoration and the tooth beingmatched can be readily detected and mayappear to be a mismatch in shade. This whyachieving a good value match is much moreimportant than a perfect hue match.

Despite its popularity, the VITA ClassicShade Guide is hue-based. Its tabs are subdi-vided into the following 4 major hue groups:A = reddish brown, B = reddish yellow, C =gray, and D = reddish gray. Each of those pri-mary hue groups is further broken downinto 3 to 5 variations of the same hue withincreasing chroma (ie, for the A hue group,the variations are A1, A2, A3, A3.5, and A4,and for the B group, the variations are B1, B2,B3, and B4). Of course, each of the individualtabs does possess a specific value and may bearranged from lightest to darkest. TheChromascop Shade Guide (Ivoclar Vivadent)is also hue-based. It has 20 possible shades inthe following 5 hue groups: Group 100 =white, Group 200 = yellow, Group 300 = light

Mark L. Pitel,DMD

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Figure 1. VITA Classical Shade Guide (VITA) has 16 shade tabs arranged by 4 standard hue groups.

Figure 2. VITA Tooth Guide 3D Master (VITA) has 26 regular shade tabs and is currently the only “value-based” shade guide.

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brown, Group 400 = gray, and Group500 = dark brown (Figure 3). Each huegroup has 4 shade variations ofincreasing chroma (ie, Group 100 =110, 120, 130, and 140). Another popular guide, the

Trubyte Bioform Color Ordered ShadeGuide (DENT SPLY Trubyte) has 24shades that are based more directly onMun sell’s work1 rather than on com-mercial factors. Its shade tabs are bro-ken down into the following 4 hues:reddish brown, yellow, gray, and red-dish gray. The guide may be purchasedin 2 different materials—plastic andporcelain—and 2 different versions—Style A, where all 24 tabs are orderedby value from lightest to darkest, andStyle B, where the tabs are ordered firstby hue and then lightest to darkestwithin the hue group (Figure 4). It isworth noting that the only tooth shadeguide which uses a value-based designis the Vitapan 3D Master and its varia-tions (Vitapan 3D Master BleachGuide, Linear Guide). Including theoptional bleach shades, it has 26 tabsthat cover the following 6 value-basedgroups: zero, 1, 2, 3, 4, and 5 (with zerobeing the lightest or highest value and5 being the darkest or lowest value).Within each value group, there are thefollowing 3 hue variations: M = stan-dard hue, L = yellow, and R = red. Eachof the hue groups is further differenti-ated by 2 or 3 chroma variations (ie,1M1, 1M2, and 1M3). In spite of thelimited shade range and less than idealdesign for all manual shade guides,they are so universally entrenched into

clinical and dental laboratory practicesand dental material manufacturingthat we are forced to use them to theirbest capacity and potential.

MANUAL SHADE GUIDESSUGGESTIONS

TO OPTIMIZE SHADE MATCHING 1. Try to utilize a shade guide that iscolor keyed for the restorative material ormedia that you are using. In most cases,manufacturers offer their dentureteeth, porcelain powders, ceramicsblocks, and acrylic and compositeresins in the shades corresponding toone of the common shade guides(VITA Classic, VITA 3D Master,Chromascop, and Trubyte Bioform).

If their materials correlate well tothat guide, then using the brand-spe-cific guide should improve chances ofa shade match. When another shadeguide is used, the dentist or dentallaboratory needs to convert the shadefrom one guide to the color standardsof another. This second order conver-sion greatly diminishes the chancesfor a good match. If an alternate guidemust be used, sending the actualshade tab from the guide to the dentallaboratorywill help improve commu-nication of the shade and color matchneeded for the case and aids conver-sion of one color standard to another.

2. Try to use a shade guide made ofthe actual restorative material. When

using a shade guide that is made of amaterial other than the actual materi-al, it will likely have different opticalproperties. Fluorescence, opales-cence, and translucence all varygreatly from one material type toanother, and even one brand toanother; and so does surface finishand texture. Using a porcelain or plas-tic shade tab to select a shade for aresin composite may not always pro-duce a good match. If a manufacturerdoes not make such a guide available,the dentist or lab technician shouldconsider making up a custom guidefrom the actual materials.

3. Use multiple shade guides toextend the shade range coverage.

Assuming that all current guidesoffer only partial coverage of the totaltooth color space, using one guideexclusively is extremely limiting.Additional guides extend the likeli-hood of finding a better match.

4. Always take the shade at the verybeginning of the dental appointmentbefore the teeth have a chance to dehy-drate. It is well known that dehydra-tion temporarily raises the value ofthe teeth. This effect is significant andmay not fully resolve for up to 24hours.5 If you forget to take the shadeat the beginning of the appointmentand the aesthetic match of the restora-tion is critical, it is better to have thepatient return the following day fortreatment or shade evaluation.

5. Your first step in any shade evalu-ation is always to find the best valuematch. Buy your shade guides pre-arranged by value or arrange them byvalue from lightest to darkest. Even ifthey are hue-based, most manufactur-ers can offer you a recommendationfor value ordering. To save time and tohelp with finding the best hue andchroma match, it is a good idea to keepa second shade guide which has beenprearranged by hue groups.

Recommended Procedure for Using a Hue-Based Shade Guide

Step 1. Review and optimize yourambient lighting conditions6 or use adedicated task light to help facilitatethe most ideal lighting to select theshade. An example of a particularlyuseful hand held task light is the Rite-Lite 2 (AdDent). It uses 2 types of LEDsto provide a choice of the following 3different controlled light tempera-tures: 5,500 K (the daylight standardfor dentistry), 3,900 K (ambient mix),and 3,200 K (incandescent). This of -fers the operator the ability to judgethe shade match under differing light-ing situations and help avoid prob-lems related to metamerism (Figure5). Metamerism happens when 2shades appear to match well under aspecific lighting condition or colortemperature, but match poorly underdiffering lighting conditions. Thistask light also makes use of dispos-able mauve color cards which can beused a backdrop to help reduce colordistractions and more accuratelydemonstrate the tooth’s value.7

Step 2. Get 2 identical shadeguides. Prearrange the tabs of oneguide in value order (lightest to dark-est) with the incisal edges of the tabsfacing up and away from the holder.Leave the other guide in its nativeorder arranged in hue groups with thecervical portion of the tabs facing up.

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Figure 3. Chromascop Shade Guide (Ivoclar Vivadent) has 20 shade tabs arranged in 5 huegroups by increasing chroma.

Figure 4. The Trubyte Bioform Color Ordered Shade Guide (DENTSPLY Trubyte) has 24 shadetabs, which cover 4 hue groups. It is available in plastic and porcelain varieties.

Figure 5. This handheld LED task light (Rite-Lite 2 [AdDent]) helps optimize lighting conditions. It offers the operator 3 differentchoices for lighting: daylight, incandescent,and an ambient mixture.

Figure 6. To establish value, orient theshade tabs with their incisal edges towardthe tooth. Concentrate on the junction of themiddle and incisal one third.

Optimizing Your Shade-Matching...

If an alternate guide must be used, sending the actual shade tab from the guide to thedental laboratorywill help improve communication of the shade and color match needed....

AESTHETICS

Lightly wet the patient’s teeth and thetabs of the guide with water or a clearfluid to eliminate any surface texturaldifferences. Using the guide whichhas the value ordered tabs, squint theeyes slightly while quickly movingthe various tabs across the toothbeing matched. As the tabs move, tryto focus on the junction betweenincisal and middle one third of theteeth and tabs and only on their rela-tive brightness (value). In most cases,you should be able to eliminate mostof the tabs while finding 2 or 3 tabsthat seem to match well to the bright-ness range of tooth (Figure 6). If youhave a digital camera available, take 2images of the selected tabs againstthe tooth, one in monochrome orgray scale and one in color (Figure 7).The monochrome photo demon-strates only value information, so itcan help confirm a value match whilethe color photo can be used to evalu-ate hue and chroma.

Step 3. Now take the other shadeguide, which has the tabs set upaccording to hue with the cervicalportions facing up. If the tabs youpreselected for value fall within only

one hue group, you may skip to step 4to establish the best chroma. If morethan one hue group is represented inthe value selections, you’ll need todetermine which hue group providesthe best color match. For hue match-ing, focus mainly on the junction ofmiddle and cervical one third of thetooth and the shade tabs. If using aVITA Classic Shade Guide, you maywant to grind off the necks of the tabsbecause these tend to be higher inchroma and could distract from thetrue hue (Figure 8). As before, try toeliminate obvious hue mismatchesfirst leaving the one hue group thatseems the best overall match. Toavoid color fatigue, each color assess-ment should take no more than 5 sec-onds and may be improved by occa-sionally looking at a neutral gray orblue colored card or patient napkin.

Step 4. The final step is to estab-lish the best chroma. Once you haveselected the appropriate hue group,remove those tabs from the shadeguide, fan them out, and pass themacross the tooth being matched. Witha little luck, you’ll find one tab that isthe best chroma match to the tooth.

As a final check, take color andgrayscale photographs with the tabselected near the tooth to help verifythe value, hue, and chroma of yourselection.

VALUE-BASED SHADE GUIDESRecommended Procedure

To select a shade with a value-basedshade guide (VITA 3D Master), thefollowing clinical protocol is recom-mended.

Step 1. Review clinical and ambi-ent lighting conditions or use a dedi-cated task light to facilitate the mostideal lighting.

Step 2. Evaluate the best valuegroup. While this can be done with alltabs in the 3D Master guide, it is some-what easier if you remove all of the Rand L hue groups from the guide leav-ing only the M hue groups (Figure 9).Alternatively, it may be more conven-ient to purchase a Valueguide 3DMaster (VITA), consisting of only the 6value tabs in the M hue (Figure 10).Starting from darkest to lightest, movethe tabs across the tooth beingmatched while squinting the eyesslightly. It should be easy to eliminate

some groups/tabs that are obviouslytoo light or dark. Remove those tabsfrom the guide. Focusing on theremaining tabs, try to select the 3value groups where one is clearlylighter than the tooth being matchedand one is clearly darker than thetooth. Select the value group betweenthose 2. If you are not sure which isthe best for value, take a monochromeor grayscale photograph of the shadetab and tooth. This will be very help-ful to confirm the best value match.

Step 3. The next step is to selectthe most appropriate chroma. Takethe M hue group with the value deter-mined earlier out of the holder andfan the 3 tabs out. Pass each tab one ata time over the tooth adjacent to thetooth being matched viewing themside by side. Try to select the bestchroma match of the 3 tabs. In mostcases, if you have gotten a very closematch with the value and chroma, itmay not be necessary to look at varia-tions in hue.

Step 4. The final step would be to“confirm or refine” the hue. The Mhue group is found exactly in the mid-dle of the yellow to red color range of

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teeth and is therefore orange. Studieshave shown that this hue is very closeto more than 50% of the population.However, if you feel the actual hue forthe tooth being matched is skewed tothe yellow or red range, you’ll want toevaluate the L (yellow) and R (red)hues. These hues only contain 2 possi-ble chroma variations, one light andone dark. Even if a color shift is notsuspected, it is a good idea to confirmthat an L or R hue is not better thanthe M hue. As before, always confirmyour final hue, value, and chromaselection by taking a color and gray -scale photograph using electronicflash as the sole illumination.

TECHNOLOGY-ASSISTED SHADE MATCHING

Included in this high-tech arena areelectronic digital shade analyzers,computer software assisted shade-matching programs, and digital cam-eras, which have been discussed pre-viously. Several clinical studies haveconfirmed that these devices may bemore accurate and more consistentthan subjective shade assessmentusing manual shade guides.8 Ideally,they can help provide an objectivetool that can complement or evensupersede a subjective approachusing standard manual shade guides. There are a few key technological

variations found in the digital shadeanalyzers of which the dentist shouldbe aware. First, these fall into 3 maincategories: RGB devices, spectropho-tometers, and colorimeters. RGB de -vices are the least complicated andwork by capturing a digital image,which is then used for additive color(red, green, and blue) and chromaticmapping. The final color maps areinterpreted by complimentary soft-ware to elicit shade information. Theweak link for these devices is the qual-ity of the digital image captured. Withhigher quality optics and digital sen-sors, they should provide clinicallyuseful shade information. How ever,these devices may not be able to effi-ciently evaluate other key color vari-ables that were discussed earlier. So itis highly important that the coloranalysis obtained from an RGB devicebe confirmed subjectively. To theauthor’s knowledge, there are nolonger any dental RGB shade analyzersthat are commercially available. TheShade Scan (Cynovad) is an example ofa previously available RGB shade-matching device.

Colorimetersmake use of filters tomeasure the intensity of red, green,and blue light reflected from theobject/tooth. This is sometimes

referred to as tristimulus values. Assuch, they are engineered to work ina similar fashion as the human eye.The color filters reduce the total spec-tral information down to just a fewkey wavelengths. This lowers dataloads and manufacturing costs whileincreasing operational speeds. Be -cause color filters are subject to agingand fading, the long-term accuracy ofcolorimeters may be adversely affect-

ed. Overall, they are thought to bemore accurate than RGB devices butless accurate than spectrophotome-ters. The ShadeStar (DeguDentGmbH) is an example of a smallportable colorimeter that is still com-mercially available (Figure 11). TheShadeVision (X-Rite) and ShadeEyeNCC (Shofu Dental) are examples ofdental colorimeters that are nolonger available commercially.

Spectrophotometers are the finalgroup of digital shade analyzers andare considered to be the most accuratefor color matching in dentistry. Theymeasure and record the amount of vis-ible radiant energy reflected or trans-mitted by an object/tooth one wave-length at a time for each value, chro-ma, and hue present over the entirevisible spectrum, generating consider-able amounts of data. Until recently,the complexity and expense of pro-ducing spectrophotometers has hin-dered their introduction into den-tistry. However, as in other areas oftechnology, miniaturization and man-ufacturing costs have fallen, making itpossible to produce affordable andpractical units for dental research andclinical use. Examples of dental spec-trophotometers that are currentlyavailable include the following: TheEasyshade Compact (VITA) (Figure12), SpectroShade Micro (MHT OpticResearch), and the Shade Pilot(DeguDent GmbH).One important feature for all digi-

tal shade devices is whether they aredesigned for spot measurements (SM)or for complete tooth measurements(CTM). The average optical diameter ofthe SM shade device is 3 to 5 mm, thusproviding only a limited spot readingof color and shade. Considering thatmost teeth are not monochromatic,multiple readings should be takenwith SM devices to ensure that the den-tist and technician have an accuratemapping of the tooth’s shading. Incomparison, CTM devices read theentire tooth surface and provide a com-plete map of colors and shades. MostCTM devices allow the color maps to beprinted or transmitted electronically. An interesting and innovative

alternative to purchasing a digitalshade analyzer is to use a shade-match-ing software program that works withthe dentist’s own digital camera andclinical photographs. Shadewave Soft -ware (Shadewave) is a cloud-based soft-ware program that maps a tooth’sshades to popular dental shade guidesfrom a color digital image obtained

Figures 7a and 7b. A monochrome image (a) confirms a good value match while the colorimage (b) is used to establish the hue and chroma.

Figure 10. A Valueguide 3D Master (VITA)may further simplify selecting the correctvalue for some operators.

Figure 11. The ShadeStar (DeguDent GmbH)is a cordless handheld colorimeter for objec-tive digital shade matching.

Figure 8. To establish hue and chroma, orient the tabs with their necks toward thetooth. If using a VITA Classic Guide, grind offthe extension of the neck to improve discrimination of hue. Concentrate on thejunction of the cervical and one third.

Figure 9. Removing the L and R shadedtabs from the VITA 3D Master guide may be helpful in isolating the correct value ofthe tooth.

a b

Figure 12. The Easyshade Compact (VITA) isa cordless, digital spectrophotometer provid-ing digital shade readings corresponding tothe VITA Classic and VITA 3D Master Guides.

Figures 13a and 13b. Cloud-based Shadewave Software (Shadewave) analyzes a clinical photograph (containing a visual target) submitted by the dentist and provides a shade mapfor the reference guide selected.

a b

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AESTHETICS

with any camera or optical recordingdevice (Figure 13). The dentist simplyuploads the image to the company’swebsite and then performs the shadeanalysis using the online softwareinterface. The advantage of a cloud-based approach is that the software iscontinually updated and can be uti-lized with any Internet accessibledevice such as a computer, tablet, orsmartphone. Since digital camerasand images can differ greatly in quali-ty and color accuracy from one toanother, color standardization isrequired prior to performing the finalshade analysis. This correction isaccomplished by analyzing a hand-held color reference which is simulta-neously captured in the digital imagewith the tooth. After normalization ofthe uploaded photographic image, thesoftware compares the shades and col-ors detected in the digital photo andmaps them to a database of commer-cially popular shade guides. The shademap generated can be stored onlinefor future reference, printed out forclinical use, or sent digitally to a den-tal laboratory. One limitation of thisapproach is that the dentist cannot tellwhich of the possible shade guidesprovides the closest match to the nat-ural tooth. If a chosen guide does notcorrelate well, the shades mapped to itwill only be approximations.

CLOSING COMMENTSAchieving an excellent aesthetic matchbetween a dental restoration and a nat-ural tooth is no longer considered to beelective. Our dental pa tients expect anddemand natural-looking, aestheticallypleasing res torations. If you are usingmanual shade guides, keep multipleguides on hand and use all of them tocover more tooth color space andimprove the chances of finding a bettershade match. Make sure that the areawhere shade selections are being madehas appropriate ambient lighting con-ditions. Consider using a handheldmultispectral task light to help opti-mize the light to ideal standards andavoid errors due to metamerism (Rite -Lite 2). Sending the shade tab to the lab-oratory can help communicate theshade more accurately. Use a “valueordered” arrangement for the tabs inyour manual shade guides and startevery subjective shade evaluation withvalue assessment. Keep all color evalu-ations to 5 seconds or less and utilize aneutral gray or blue card handy torefresh the cones of the retina. Have ahigh-quality digital camera in the of -fice with an electronic flash. Adjust thecamera to use the flash as the primarylight source and set the white balance

to daylight or electronic flash. Cap -turing grayscale (monochrome)images of the shade tab and tooth helpsidentify a good value selection while acolor image can beused to narrow downhue and chromachoices. If budgetallows, using a tech-nology-based shade-taking device canoffer an objective eval-uation to complimentyour subjective assess-ment. But don’t relysolely on technology,because the hu maneye is still the ulti-mate judge of an idealshade match.�

References1. Munsell AH. A Color

Notation. Boston, MA:George H. Ellis Co; 1905.

2. Hall NR. Tooth colourselection: the applicationof colour science to den-tal colour matching. AustProsthodont J.1991;5:41-46.

3. O’Brien WJ, Hemmen -dinger H, Boenke KM, etal. Color distribution ofthree regions of extractedhuman teeth. Dent Mater.1997;13:179-185.

4. Paravina RD, Powers JM,Fay RM. Color comparisonof two shade guides. Int JProsthodont. 2002;15:73-78.

5. Pizzamiglio E. A color selec-tion technique. J ProsthetDent. 1991;66:592-596.

6. Color-correct fluorescentlighting. 1. Ideal illumina-tion for shade taking. CRAFoundation Newsletter.2007;31:1-2.

7. Tooth color matching—what can be done toincrease accuracy? CRAFoundation Newsletter.2005;29:2.

8. Paul S, Peter A, PietrobonN, et al. Visual and spec-trophotometric shadeanalysis of human teeth.J Dent Res. 2002;81:578-582.

Dr. Pitel is currently anassociate clinical profes-sor of operative dentistryat the Columbia Uni -versity College of DentalMedicine and coursedirector for predoctoralaesthetics. He also main-tains a private generalpractice in Poughkeepsie,NY, with an emphasis oncosmetic, restorative, andimplant dentistry. A pastpresident of the NewJersey AGD, he is anactive member of numer-ous other dental organiza-tions such as the ADA,the AGD, and the Ameri -can Academy of CosmeticDentistry. He has re -ceived his Fellowshipfrom the American Col -lege of Dentists, the AGD,and the Inter national

Academy of Dentofacial Esthet ics, and heholds Level II certification from the Academyof Laser Dentistry. He has authored numer-ous scientific papers and abstracts and is theauthor of a textbook on dental impression-

taking. He can be reached at (845) 454-0790or via email at the address mlp@drmarkpi-tel.com.

Disclosure: Dr. Pitel reports no disclosures.

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