A 60-year-old male patient needed endodontic treatment and crowns on teeth #9 and #10. Shown here are the nearly black post and cores that had to be masked. The best material option for this case was zirconia because it easily blocks the internal color, causing no interference with the external shading. Note that the gingival embrasure between teeth #8 and #9 is concave—basically a black hole; the existing composite on the incisal/mesial corner of central #8 would have to be mimicked somewhat on the adjacent restoration; and there’s a grayish/pink color in the body-middle third with an orange crack line. I recorded all of this information on my Custom Shade Chart (see “Shade-Matching Tips” for more information) and took patient photos.
I used three custom porcelain shade tabs—MY9, MY12 and MY13—from the LSK121 Chairside Shade Guide™ to help determine the final shades.
The model was scanned using Amann Girrbach’s Ceramill® MAP400 scanner, exocad software and the zirconia copings were milled with Amann’s Ceramill® Motion 2. Here is a facial view of the zirconia copings with an A1 base. I noted the incisal height on the model which provided information about my next step.
In comparison to teeth #7 and #8, the facial of #9 and #10 would need reduction and multi-layering of the porcelain to achieve an even flow of size, color, shape and contour.
Following the information I recorded in my Custom Shade Chart, I applied GC Initial Dentin with a C2 base then applied translucent modifier #5, gray in color, horizontally toward the mesial area. The turquoise color denotes enamel opal #4—light blue and gray—spread out in the incisal third.
To mimic the composite incisal edge in tooth #8, I used a more opaceous dentin color, GC’s Initial MC IN 41, and 58 enamel overlay. After glazing, I used a medium rubber polish wheel from Wagner Precision Rotary Instruments at 10,000RPM to dull it slightly.
With a pointed brush, I applied three layers of porcelain—gray, subtle white and blue—to the mesial-incisal third in three different vertical segments in .1mm to .3mm thicknesses. This was a critical step in matching the patient’s natural dentition.
After firing at 810°C, I checked the fit and interproximal contacts on the model.
I created surface texture and fine-tuned the shape using a diamond bur and then a diamond wheel with coarse and medium grits from Wagner.
After glazing, the gingival gray/orange tone on the solid cast model is visible. The body section is whiter in tone toward the incisal area with orange/brown covering all outer sections along with a transparent glaze layered over the top.
In the completed restorations, you can differentiate shading, tones, exaggeration of the central’s color and the lateral’s lighter shading. This natural beauty is derived from the many color tones used to create harmony and esthetics.
Tooth #9 was tried in and photographed to verify color. Note how its incisal edge mimics the composite incisal edge on tooth #8.
Both restorations were inserted as a try-in.
The Final Result
The patient’s smile illustrates a near-perfect match.
Here are some tips and tools I use to fabricate the best custom shade possible:
1. Custom Shade Chart. I designed this chart to record all the information I need to select the color of the final restoration, including the patient’s age, sex, and internal color or stump shade. There’s also a place to draw a color map of the tooth; this descriptive chart helps me record the correct color mapping information from the gingival third and mesial-incisal third, both horizontally and vertically. I use this color “road map” to create the ideal shade and also for a QC check of the final restoration.
2. The LSK121 Chairside Shade Guide™: Since I feel traditional shade tabs don’t accurately reflect the patient’s dentition, I developed two shade guides with porcelain shade tabs that include dentin/mamelon/enamel color. The two guides—anterior/rehabilitation and posterior—categorize color according to the tooth’s location: central, lateral and cuspid, premolar or molar. As opposed to a monochromatic shade tab, my shade guides help me to better recreate natural-looking color for the mesial-distal and incisal third areas. (To download a pdf of the chart, click here: http://s3.amazonaws.com/voxle.net/lmt/assets/53e24a389aa49.pdf)
3. Once I’ve documented all of this shading information, I study the photos I’ve taken and communicate with the patient about his smile and what he’s hoping to achieve. For instance, does he have any plans to further change his dentition—like whitening or additional restorations? Should I match the current color of his dentition or try to change/improve it?
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Owner at LSK 121 Dental Prosthetics
Luke Kahng, CDT, is the Owner of LSK121 Oral Prosthetics in Naperville, IL. In addition to being a board member for several dental publications, he has published more than 100 articles with major dental...
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Here's the Shade-Matching chart.