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  1. 1. CliniCal SCienCe and art Parker Shade Matching for Indirect Restorations in the Esthetic Zone AbstrAct Selecting the proper shade for an indirect restoration in the esthetic zone is of paramount importance. The process can be both difficult and time con- byRichard M. Parker, D.D.S., F.A.G.D. suming. This article delineates a clinical protocol for shade taking, labora- tory communication, and assessment of the final restoration to make the Lemont, IL process easier and more accurate. In addition, there will be limited discus- www.parker-dental.com sion of color, shade guides, office environment, instrumentation, digital photography, placement, and troubleshooting. Simply picking a shade tab to communicate the desired appearance of the restoration to the laboratory is inadequate. IntroductIon Matching a shade for one or more indirect restorations in the esthetic zone can be very difficult, time consuming, frustrating, and expensive. The dentist, laboratory technician, and patient all are involved in the process. An improper shade selection, poor laboratory communication, or an inad- equate assessment of the final restoration by the dentist and patient can lead to an esthetic failure. The appearance of a tooth is not monochromatic; but, rather, a blend of various shades, translucencies, opacities, surface textures, gloss, and char- acterizations (e.g., maverick colors, craze lines, perikymata, incisal halos, hypocalcification marks). Therefore, simply picking a shade tab to commu- nicate the desired appearance of the restoration to the laboratory is inad- equate. Today’s clinician must accurately select the matching shade, properly communicate the tooth’s appearance to the laboratory technician, and be able to assess the final restoration before placement. 98 The Journal of Cosmetic Dentistry ©2008 Winter 2008 • Volume 23 • Number 4
  2. 2. CliniCal SCienCe and art Parker Figure 1: Various preoperative views of the mismatched PFM crown on tooth #7 in context with adjacent teeth. Photographs are taken from various angles, with and without retraction. color And shAde Assessment lected hue or color. Also, the elec- should be 5500 Kelvin color tem- consIderAtIons tronic shade-taking devices often perature, 1600-2100 Lux intensity, The first requirement for the cli- are keyed to shade guides. A num- and have a Color Rendering Index nician is to have a basic knowledge ber of shade guides are available but of 90 or greater.6,7 Using a variety of of color in order to begin the pro- I believe that the one that best rep- light sources can lessen the problem cess of shade selection. The Munsell licates the teeth’s hues, value, and of metamerism, which is the change Color System divides color into hue, chroma is the Vita 3-D Master Shade in appearance of an object under chroma, and value. Simply stated, Guide.4,5 This guide is composed various light sources. Additionally, hue is the actual “color” (e.g., yellow, of the yellow-red color space that diffusers should not be used on brown); chroma is the saturation or naturally occurs in teeth. The tabs the light source as they change the degree of hue; and value is the hue’s are arranged from high value to low bulbs’ properties. The treatment relative lightness or darkness. value, and within each value group room environment (floors, ceilings, are yellow and red hues and various and cabinetry) should have a neutral Selecting a color can be accom- chromas. light gray background.8 A patient’s plished in several ways. The two lipstick, clothing, and clinical drape most widely used methods are vi- also can adversely affect the clini- sual selection, or via photocolomet- The clinician’s knowledge, color cian’s color perception. ric instrumentation. The former is perception, and ocular fatigue fraught with more variables than is can all contribute to inaccurate the latter. The clinician’s knowledge, assessments. lAborAtory communIcAtIon color perception, and ocular fatigue One of the main problems that can all contribute to inaccurate as- The office environment where the technicians have with dentist-lab- sessments.1 Shade selection with an shade selection process and evalua- oratory communications is that of electronic shade-taking device (e.g., tion of the restoration take place also shade selection.9 Along with proper Easyshade [Vita, Vident; Brea, CA]; can play an important role in color shade selection, the dentist must ShadeEye [Shofu, San Marcos, CA]; perception. Lighting, office décor, communicate the various tooth ShadeVision [X-Rite, York Dental; and bold colors near the oral cavity characteristics such as translucency Branford, CT]) offers a reliable alter- can influence shade selection. and surface texture. This is best ac- native to visual shade matching.2,3 complished by the use of digital Office lighting should, ideally, be This allows dentists and others to photography.10 a combination of natural daylight eliminate inaccuracies associated Photographs should be taken of and color-corrected fluorescent light- with visual assessment alone. the teeth preoperatively and with ing. Natural light should be indirect Shade guides are needed to com- and the fluorescent bulbs optimally the selected shade tabs; and of the municate to the laboratory the se- preparation with a matching shade 100 The Journal of Cosmetic Dentistry ©2008 Winter 2008 • Volume 23 • Number 4
  3. 3. CliniCal SCienCe and art Parker Figure 2: Spectrophotometer taking the shade of the contralateral tooth. Figure 3: The selected shade tab is photographed in line with the long axis of the teeth, along with neighboring tabs to “bracket” the desired shade. This helps the laboratory technician determine the proper color relationship.tab. Photographs should be taken ones to “bracket the shade.”5 This ration may look good in the labo-from various angles. This will allow will enable the ceramist to adjust for ratory, but it may look different inthe technician to better judge trans- these color variations because they the dental office if the lighting is notlucency, color, and surface texture.10 know the color of the shade tabs coordinated.The photographs should range from represented in the photographs.11full smile to several teeth. The lighting in the laboratory One of the main problems that Variations can occur with camer- should mimic the lighting in the technicians have with dentist-as, monitors, and printers that may clinical dental environment.6 For laboratory communications is thatrender inaccurate color. One way example, if the dentist has a blend of shade selection.to correct this problem is by using of natural light and color-correctedcolor-correct software and monitor- fluorescent light, then the techni-calibration software to match the cian should have the same. This is Lastly, no matter how a shade isimages between the dentist’s and important as it can influence the selected, how many photographsthe technician’s monitors. A simpler appearance of the monitor, and of are taken, and regardless of whatmethod is to photograph the desired printed photographs, shade tabs, type of high-tech instrumentationshade tab along with two adjacent and the final restoration. The resto- is used, it is still necessary to have a laboratory technician who can inter- The Journal of Cosmetic Dentistry ©2008 Winter 2008 • Volume 23 • Number 4 101
  4. 4. CliniCal SCienCe and art Parker Figure 4: The color of the prepared tooth is taken. Figure 5: The restoration is held in line with the This information is important for the ceramist to non-desiccated teeth to determine if the shade is determine how much of the preparation needs to be approximately correct prior to try in. blocked out to achieve the desired final appearance. pret the data and transform it into tographs or during shade selection, ets” the selected shade and the po- a beautiful porcelain restoration. A the teeth cannot be allowed to be- sitioning gives a truer comparison dentist needs to find a talented cera- come desiccated. The drying of the to the natural teeth. Note that the mist and develop a strong working teeth will change their appearance selected shade is the one that corre- relationship with him or her. This and give an inaccurate shade and sponds most closely to the body of involves setting mutual protocols thus, inaccurate photographs to the the tooth. and expectations. laboratory. A simple way to prevent this is to have the chair-side assistant PrePArAtIon keep the teeth wet with moist gauze Once the existing restoration clInIcAl Protocol was removed and the preparation or with water from the three-way sy- Assessment ringe, and to remind the patient to was refined, a “prep” or “stump” close their lips when not being pho- shade photograph was taken with An adult female presented with tographed. a Die Material shade tab (Ivoclar an existing restoration on tooth #7 Vivadent; Amherst, NY) (Fig 4). Al- (Fig 1). The porcelain-fused-to-met- The preoperative photographs most any shade guide can be used al (PFM) crown had been placed on give information to the technician to roughly determine the color of a discolored endodontically treated about both the existing restoration the prepared tooth. This is impor- tooth 14 years earlier, and no lon- but, more importantly, about the tant, as the laboratory technician ger matched her adjoining teeth adjacent teeth (Fig 1). Vita’s Easy- needs to know how much block-out after she whitened them (Fig 1). shade spectrophotometer was used has to be built into the restoration Although the restoration was sound on the contralateral tooth to select a to achieve the desired appearance. and functioning, the patient wished shade (Fig 2). Prior to the use of the The more translucent the proposed to have it replaced for esthetic rea- device, it was visually determined restoration, the more critical this sons. An all-ceramic crown was cho- that #10 was typical of the maxillary step becomes. Restorations can vary sen to restore this tooth. anterior teeth and was not an aber- from opaque (e.g., PFM) to semi- ration. PreoPerAtIve translucent (e.g., zirconia oxide and Once the shade was selected, Prior to photographs for labora- aluminous oxide) to more translu- the corresponding Vita Master 3-D tory communication, the anterior cent (e.g., pressed ceramic and feld- shade tab was held, along with adja- teeth were cleaned with pumice and spathic porcelain).12 cent shades, in line with the incisal water, with care taken not to cause edges of the teeth and the tab desig- any gingival bleeding. It must be nations visible (Fig 3). This “brack- emphasized that while taking pho- 102 The Journal of Cosmetic Dentistry ©2008 Winter 2008 • Volume 23 • Number 4
  5. 5. CliniCal SCienCe and art Parker Figure 6: The crown is photographed from various angles and distances during the try-in phase to ascertain if the appearance is acceptable.Figure 7: Images of the restoration after it has been cemented in place. Note the color match and the similar translucency, surface texture, and characterizations to those of the adjacent teeth.restorAtIon evAluAtIon With the final crown un-cement- PlAcement And troubleshootIng Once the restoration is received ed and care being taken to avoid Depending on the translucencyfrom the laboratory, it should be desiccation, the tooth is checked of the restoration, if, at the try-inchecked to ensure that it approxi- for appearance and then it is pho- phase, the shade is “off” slightly, themates the shade tab selected. If it is tographed from different angles and appearance can be adjusted via thenot close, the lab needs to be con- distances (Fig 3 ). The digital pho- color of the cementing or bondingtacted and the restoration returned. tographs are then viewed in the of- medium. This can be accomplishedThe diagnostic information then fice by the dentist to further evaluate using try-in pastes that match theneeds to be reviewed with the tech- the match. In addition, the patient is bonding material and repeating thenician to determine the cause of the asked to look at the smile in a mir- evaluation process. If changing theerror. ror. cement color does not improve the After the restoration has passed If the patient approves the es- esthetics or the restorative materialthe initial evaluation, it then can be thetics and the clinician is satisfied lacks translucency (e.g., PFM) to beevaluated with the patient. Without with the appearance, fit, and occlu- affected by the cement choice, thendesiccating the teeth, the crown is sion, the restoration can be seated. the restoration itself needs to be ad-held in line with the patient’s adja- The patient is asked to sign a brief justed. In the clinical case presentedcent tooth to check that the shade form stating approval of the crown’s here, the crown matched well with-is “in the ballpark” (Fig 3). If its esthetics, and understanding and out any try-in paste, so the cementappearance is approved, the tempo- agreement that any changes after- color chosen for final placement wasrary crown can be removed from the ward will involve a fee. “clear” (Fig 4).tooth and the ceramic crown tried Usually in these cases, errors oc-in. cur in the chroma and value. Rarely The Journal of Cosmetic Dentistry ©2008 Winter 2008 • Volume 23 • Number 4 103
  6. 6. CliniCal SCienCe and art Parker is it the hue, especially if an electron- Acknowledgment ic shade-matching device is used. The author thanks dental technician Therefore, if the chroma is too low Roland Tasker of Roland’s Dental Ce- or the value too high, the restoration can be stained chairside with tints to ramics (Lemont, IL) for fabricating the Patient Education restoration shown in this article. achieve the appropriate appearance. Doesn’t Just Start Then the stained restoration, along References and Stop at Your with photographs of it in the mouth, 1. HealthMantra.com. Shade selection and is sent back to the laboratory for the management. Accessed December 7, 2007, Office. at http://tinyurl.com/32ncgl. technician to revise. 2. Hu X. Comparison of Clinical Color Measur- If the restoration has too much ing Instruments’ Performance on Dental Por- chroma or is too low in value, the celains. IADR/AADR/CADR 85th General Session and Exhibition. New Orleans, LA; problem is a bit more complex. A March 21-24, 2007. call to the lab can determine if any 3. Dancy WK, Yaman P, Dennison JB, O’Brien surface tints or stains are present. WJ, Razzoog ME. Color measurements as If so, polishing of the surfaces will quality criteria for clinical shade match- ing of porcelain crowns. J Esthet Rest Dent remove the surface coating and de- 15(2):114-21, 2003. crease the chroma and raise the val- 4. American Dental Association. Dental ue. If surface staining is not present, product spotlight: Dental shade guides photograph the restoration with the JADA 133:366-367, 2002. bracketed shade tabs and return it to 5. Ward D. Clinical Photography [course]. Es- the laboratory. The technician will thetic Dentistry Program, Department of Continuing Education, University of Min- then need to re-layer the porcelain nesota, Minneapolis, MN; November 13, to correct the discrepancies. 2005. Inform patients that 6. CRA Foundation. Tooth color matching: What can be done to increase accuracy? you are a member dIscussIon CRA Newsletter 29(3)1-3, 2005. of the world’s largest When treating a tooth in the es- 7. CRA Foundation. Color-corrected fluores- organization dedicated thetic zone, the appearance of the cent lighting. CRA Newsletter 31(4):1-2, 2007. to advancing excellence restoration takes on as much im- in the art and science of 8. American Dental Association. Tips on im- portance as the fit and occlusion. proving shade matching. JADA 133:367, cosmetic dentistry and If the visual quality is deficient, the 2002. encouraging the highest patient will not be satisfied. The 9. Small B. The laboratory perspective: The top ten problems with communication. standards of ethical clinical protocol described here can greatly increase the accuracy of Gen Dent 55:280-283, 2007. conduct and responsible shade matching; and decrease the 10. Kinzer GA. Laboratory communication: patient care. The key to clinical success. Adv Esthet Inter- time, expense, and frustration of discip Dent 3(1):26-32, 2007. all involved. Because no procedure 11. CRA Foundation. Photos for communica- is foolproof, it may be prudent for tion with lab technicians. CRA Newsletter Request the AACD the dentist to adjust the restorative 29(5):1-3, 2005. Member Marketing fee to compensate for the increased 12. Spear F. Contemporary Esthetic Techniques Kit complete with and Materials Part 1: Material Selection. time needed to treat a tooth that is AACD 23rd Annual Scientific Session; At- professional tools easily visible. Furthermore, the pa- lanta, GA, May 17, 2007. designed to help you tient should also be informed of ______________________ market your practice the potential for multiple visits to v or lab, via e-mail at achieve a satisfactory result. With a pr@aacd.com or call definitive step-by-step methodology in place, matching a shade is less (800) 543-9220. stressful and more precise. 104 The Journal of Cosmetic Dentistry ©2008 Winter 2008 • Volume 23 • Number 4

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