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Luke S. Kahng is an accomplished lab technician, specializing in high-end ceramic restorations. Luke has served on several major dental journal boards as a contributing member. Luke invented the Chairside Shade Guide: Volumes 1 and 2 and then expanded the offering to a unique ceramic shade guide system named the Seasons of Life Selection. He is owner and President of his own lab, LSK121 Oral Prosthetics, located in Naperville, IL. He has published over 100 articles in major national dental publications.
Dental technology is moving at a very fast pace and products are changing all the time. Convenience is key, and in this current economic situation, we all want to be more efficient with our materials to cut down on our overall costs. Everyone is searching for ways to save time but still achieve the best possible results. The following procedure shows how one porcelain powder can be used to achieve outstanding results. This system is very simple to master and easy to work with. Case Study
Dental technology is moving at a very fast pace and products are changing all the time. Convenience is key, and in this current economic situation, we all want to be more efficient with our materials to cut down on our overall costs.
Everyone is searching for ways to save time but still achieve the best possible results. The following procedure shows how one porcelain powder can be used to achieve outstanding results. This system is very simple to master and easy to work with.
Indications in this difficult case were that the patient’s teeth didn’t match with any traditional shade tabs and would need adjustment. This was to be accomplished by mixing the lustre pastes together to achieve a custom match and proper harmony in the mouth.
One Body Zr Porcelain from GC America is low-fusing porcelain powder, with 810°C as the final temperature, and polishing is easily handled. Numerous choices of color make matching with adjacent teeth easy when using this product, no matter what the variation. For even more color variables, GC Zr Layering Light Reflective Liners include seven basic shades and help provide a match with especially challenging colors.
01 Tooth No. 6, which was a different color than the teeth that surround it, was to be replaced (Fig. A). This situation created an excellent scenario for experimentation with diverse materials.
02 We can see the subtle stain and the intensity of the chroma, with the posterior area of the teeth lighter in appearance than the anterior (Fig. B). Our zirconia coping was milled by the GC Milling Center, Costa Mesa, Calif. (Fig. C) in a white background. On the model, I was able to check the fit.
03 GC Initial Reflection Liner™ comes in an array of colors (Fig. D). Before the porcelain build-up, the Reflection Liner was applied to this coping in an A base. By applying the internal color we are creating depth with natural harmony.
04 After choosing the color tone to be applied (Fig. E), the technician can layer on the powder with any thickness he wants to use. This is because he only will be applying one color, not several. So there will be no cutting back of the enamel or translucency powders. All that’s left to be applied is the stain.
05 A consistent oven temperature is very important to the appearance of the restoration (Fig. F). The quality of the baking appearance can be called into question if the oven is not operating correctly. Without applying the Reflection Liner, the coping was fired at 810°C with vacuum and left with an eggshell appearance (Fig. G).
06 Next, I drew contour lines on the coping for surface texture (Fig. H). A try-in the mouth (Fig. I) demonstrated what I knew would happen-the color was too high in value and would need to be changed (Fig. J). But that was simple to fix.
07 With A tone Lustre Pastes (Fig. K) the technician can stain the crown and create a perfect match with adjacent teeth. The paste is thicker than a traditional stain (Fig. L) that can be applied to the restoration, after which it’s vibrated and fired. The results aren’t a solid color but hold many variations (Fig. M) that match natural dentition.
08 A try-in in the mouth indicated a close match with the brighter tone of the pre-molar/molar teeth (Figs. N, O). This was agreeable to both the patient and the clinician.
For a systematic approach to color harmony, use the featured Zr-LR Liners to easily adjust the shade of the different ZrO2 materials.
In this case, my goal was to create a match with a color that no traditional shade tab could approach. Instead I needed a special combination of multiple colors. This was possible as I’ve shown, but so is a single-color application or an additional layer of GC Initial IQ Lustre Pastes NF.
The product can be used to create a multitude of transparencies and hues, no matter the chroma. Technicians new to the field will find this product to be easy to use with little room for error or waste.
About the author
An accomplished dental technician with more than 20 years of experience, Luke S. Kahng, CDT, is the founder and owner of LSK121 Oral Prosthetics, a dental laboratory in Naperville, Ill. He has published more than 80 articles in dental journals, and his lectures have taken him across the United States and internationally. He is the creator of the Chair Side Shade Guide Seasons of Life, 3.0, 4.0, 5.0, 6.0 and 7.0 ceramic shade tabs, which were invented to facilitate effective communication regarding color between doctors, patients and technicians.