Shading and Multi-Coloring Techniques for Zirlux 16+
Efficient, user-friendly processes produce natural-looking restorations
By Carsten Fischer, MDT
Dental laboratory technicians will always find themselves in situations in which they would like to go the extra mile and achieve better results. Therefore, having even more flexibility to achieve optimal light-optical characteristics is a significant advantage. Zahn Dental offers a proven technique and staining formula to use with its Zirlux 16+ material (white) for these cases.
In order to color the milled, monolithic zirconium oxide crowns, a technician can infiltrate the white material with liquid stain prior to sintering. This can be achieved via dipping or multi-coloring techniques. Dipping achieves a monochrome shade; all 16 VITA classical shades can be reproduced with this technique, and the result will be monochrome, without gradients (Table 1). Areas with high volume can have a more natural-looking appearance due to greater color saturation. Advanced multi-coloring can produce multi-colored restorations with blended shades and incisal effects.
This article illustrates how to achieve the desired appearance for restorations using various proven techniques with Zirlux 16+.
The dipping technique consists of submerging the restoration milled from white Zirlux 16+ raw material into liquid stain that matches the tooth color, which means very few steps are necessary: dipping, drying, sintering, and glazing.
This option is useful for laboratories that need to keep inventory to a minimum and cannot keep a supply of all Zirlux 16+ pre-shaded discs. They can keep only the most common shades of pre-shaded discs in stock and still achieve the esthetics they desire. To produce rarer colors, technicians can utilize the white raw material and the dipping option.
Adequate pre-drying and drying before sintering are very important when staining Zirlux 16+ to prevent dynamic pressure from residual liquids during the sintering phase.
If color shading is desired, this can be achieved with the multi-coloring technique. The targeted application of liquid stains enables technicians to achieve a restoration with natural color shading. For example, occlusal surfaces can be shaded in, and mamelons or interdental areas can be accentuated.
To ensure reproducible results, it is important to keep to a predetermined painting scheme and to use precisely coordinated materials.
When staining posterior teeth with the multi-coloring technique, up to five separate areas are outlined on the crown, like a map. These areas are then filled (painted) with liquid stain according to the multi-coloring scheme.
With advanced multi-coloring, liquids have demonstrated excellent staining characteristics. The areas to be stained are first outlined on the restoration—there may be up to five different color zones on one molar crown (Figure 1 through Figure 6). These areas are then filled with the appropriate stain, similar to the paint-by-number technique. If the technician follows the manufacturer’s formula, then excellent, blended color shading can be achieved, with natural internal colorations. All liquids are acid-free. Different manufacturers’ liquid colors vary in their specific color and application characteristics.
The staining brush must be metal-free. The stain formula is matched
to the brush volume. Only specialized pencils should be used for outlining coloring zones on Zirlux 16+ White surfaces. Only Zirlux 16+ White is suitable for liquid staining. Preshaded Zirlux 16+ cannot be treated with additional staining liquids because the material has been colored during manufacture.
Blue, gray, and purple staining liquids add natural-looking depth. Due to the intensity of these shades, they should be applied only once. Alternating shades in the incisal third, like piano keys, will result in a particularly natural blend of colors (Figure 7 through Figure 9).
In general, when coloring Zirlux 16+ White, it is important to pre-dry the material properly prior to sintering. This helps to prevent dynamic pressure from residual liquids during the sintering phase. Do not exceed a drying temperature of 140°C.
All restorations must be clean and free of milling dust prior to sintering. A soft brush or oil-free pressurized air can be used for cleaning. The restorations must not be allowed to come into contact with each other during sintering.
The drying time, at a distance of 20 cm from the red light, is dependent on the type of restoration (Figure 10). Crowns, abutments, and objects up to pre-molar size should be dried for approximately 1 hour. Molars and 3-unit bridges should be dried for 1.5 hours. Wide restorations should be dried for 2 hours.
Utilizing Zirlux 16+ White for dipping, multi-coloring, and advanced multi-coloring is a reliable, efficient way to create all 16 VITA classical shades. In this way, it is easy to achieve blended shading just like natural teeth (Figure 11).
About the Author
Carsten Fischer, MDT, is the owner of Sirius Ceramics in Frankfurt, Germany.
Disclaimer: The statements and opinions contained in the preceding material are not of the editors, publisher, or the Editorial Board of Inside Dental Technology.
For a table detailing multi-coloring technique requirements for Edge l, Edge II, Cervical, Dentin/Enamel, and Occlusal, go to insidedentaltech.com/idt951.
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