The White Opaque effect liquid is designed to preserve translucent incisal esthetics while masking the cervical portion of restorations that may be shade compromised due to underlying metal or extremely dark dentin. The need for masking is often exacerbated by a crown design requiring very thin axial walls.
The white opaque liquid is available in three levels of intensity or concentrations: 1, 2, and 3. 1 is “softer” and 3 is the most intense. Level 2 is the most common.
The timing of the liquid application depends on whether you are milling unshaded or pre-shaded discs:
• If you are using pre-shaded zirconia, apply one coat of the white opaque liquid to the inside of the crown once it has been cleaned and is ready to sinter.
• If you are using unshaded zirconia, clean the disc, color it and then, this is critical, DRY it thoroughly before applying one coat of the white opaque liquid. If you apply the white opaquer before you color, the wetting of the colorant will diffuse the white opaquer through the crown.
In both cases, it is recommended that you ‘warm up’ the prepared crown with a heat source such as a heat lamp, toaster oven or even a hair dryer. The purpose of slightly raising the crown temperature is so that the opaque liquid dries instantaneously on the surface and avoids any capillary action that may pull it to the facial surface. Use a fairly small brush, perhaps a #1 round sable. I put a drop of white opaque on my staining tray and paint it from there. When you apply it to a dry surface it will slightly absorb into the surface but not float around and raise the value excessively. Apply only one coat. Applying more than one coat will likely result in a visible line at the end of the prep.
Sinter normally once the white opaquer has been applied. The intaglio surface post-sintered may look a little different but the observable surface should be opacified enough to block out most anything. Application of one coat will not add any substantial thickness to impact the fit.
Finally, we recommend that you test the white opaque on a scrap piece of zirconia and keep it as a kind of shade guide for future restorations.
To extend its shelf life, we recommend refrigeration to reduce temperature and humidity. Keep out of direct sunlight and away from heat to minimize evaporation. Depending on use, it may congeal before it is fully consumed.
NOTE: The white opaque liquids may also be used to create hypo-calcification spots on the outside of the crown.