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CATEGORY LINICAL

more innovative materials to mill. One area receiving particular attention is the search for materials with ideal properties for constructing long-span frameworks. Early on, metal was the only choice, but metal is both rigid and requires high-end – expensive – milling systems tomanufacture. Recent technological advancements have led to zirconia becoming the most requested material for xed restorations in Dentistry. is column addresses the bonding of zirconia restoration o ering a handful of useful tips. Zirconia is an incredibly strong material with a exural strength ve times greater than other ceramics. It can now be applied to a variety of clinical indications including single crowns, implants, endodontic posts, and both anterior and posterior dental restorations. e evolution of translucent or aesthetic zirconia materials encourages its use without visual limitations. Zirconia is a ceramic, but it is treating zirconia like it is lithium disilicate when bonding zirconia. I like to focus on an etching solution with a new and innovative surface treatment process for zirconium oxide restorations. e etching process is easy and reliable. e solution is based on a unique mixture. e elements will be placed after sintering in this liquid, for a certain period of time. Zircos-E is the world’s rst complete system, developed in collaboration with (Korea Institute of Ceramic Engineering and Technology. Zircos-E is a liquid solution for surface treatment, which strengthens the bond with porcelain by activating ions on the surface of zirconium. With this technique, the speci c surface layer of zirconia is removed even if glazed, allowing to obtain excellent chromatic results. e adhesion strength of the cement is greatly increased through the etching of the inner surface of the crown. e sandblasting method generates a physical shock to zirconium oxide and alumina that leads to microcracks and degradation at low temperature. not an etchable ceramic, nor does it contain silica. Zirconia cannot be etched or silinated, so the bonding procedure is di erent than the one used for felspathic porcelain or lithium disilicate until 4 years ago. One of the common errors clinicians make is

treatment, commonly used on silica based ceramics. Alternative surface etching technique of zirconia coping is introduced to increase the surface roughness. A combination of acid etching with HF/HNO3 and ultrasonic

seemed to be more promising to improve bonding performance of resin-based cements. Within the limitations of this study, compared to non-etching, acid etching with ultrasonic improved the shear bond strength between zirconia and resin cements. Step 1, soak in Zircos-E acid in the container provided. After 30 min under ultrasound, Step 2,open the rinse container and put under running water, please clean the etched crowns with steamer, after using a porcelain furnace at 600 degree for 5 min for degas. Using this technique, the zirconia-speci c colour is removed fromthe surface and through glazing, excellent shades are produced. is etching technique also increases the bonding strength. It is very important to respect the safety protocol. Wear gloves and do not open the bottle or container outside the working box. Now, we are ready to glaze o build up the ceramic.

It is now also possible to etch inlays/onlays, crowns, veneers and Maryland bridges. In my laboratory in the last 3 years I created my protocol using the uid ceramic paste to glaze a full contour crown and then a glaze available in paste and spray, highly uorescent and provide a shiny and brilliant appearance to restorations, instead, for a zirconia coping and cut back I use the uid ceramic instead of liner ceramic, with average thickness 1-2 um. I use a uid ceramic mass that allows for improving the aesthetic outcome of monolithic zirconia and lithium silicate. e paste ceramic creates a ceramic interface between the zirconia and the surface-applied colours, creating greater depth and three-dimensionality.

Zircos–E® Theoretical Background

Etching Solution is a patented surface treatment technology that uses ionization to create a microporous surface and improve the bonding strength of zirconia crowns to porcelain. Because the etching solution treats the total surface area simultaneously, it also increases the bond strength of zirconia implant crowns to cement. e easy-to-follow treatment process can be completed in 30 minutes. Zircos-E Etching Solution activates the surface ions of zirconium oxide to greatly strengthen adhesion to porcelain thereby increasing the porous surface area of zirconium oxide. Zirconia cannot be dissolved by hydro uoric acid (HF)

is paste ceramic is not a simple glass, but it contains all the characteristic elements of a true traditional layering ceramic mass. is composition allows achieving a three-dimensional and natural e ect through the di usion and refraction of light in the thin ceramic layered highly uorescent to whole crown.

AUSTRALASIAN DENTIST 95