Celtra Duo Developed to make a difference

The science behind the block

Learn more about Celtra Duo (ZLS) and the recommended ways to handle the material in clinical application.

Self-healing for greater strength and durability

The high glass content of Celtra Duo (ZLS) not only gives the material its excellent light-optical and mechanical properties, it also provides the added benefit of self-healing when fired.

During the firing cycle, as the glass transition temperature is reached, the glass ceramic turns into a highly viscous "liquid"; however, not viscous enough as to lose the shape of the restoration. Rather, the viscous glass fills any flaws caused by the milling process. After firing, having gone through the self-healing stage, as the material cools to room temperature, it hardens back to its original high strength.

Excellent edge stability

Celtra Duo (ZLS) provides excellent edge stability, resulting in restorations with strong and durable margins that resist chipping.  In testing, standardized copings are cut back at the edges to a wall thickness of 200µm to examine edge stability.

The results speak for themselves.

High strength and longevity

Celtra Duo (ZLS) retains its high level of strength in long-term chewing simulations. Even after 6,000 thermal cycles (41°F to 131°F) and 1.2 million chewing cycles with 70 Newtons of force, Celtra Duo (ZLS) demonstrated no loss in strength.

Natural opalescence

The unique lithium silicate crystalite composition of Celtra Duo (ZLS) with 500-700µm particle size contributes to an opalescence that behaves like natural tooth enamel, creating a lifelike appearance and vitality in the mouth.

Fluorescence and chameleon effect

The high light conductivity and shade adaptation of Celtra DUO (ZLS) in conjunction with the remaining natural teeth and the pronounced opalescence create the desired chameleon effect.  With an inlay, for example, it's virtually impossible to discern where the restoration ends and the natural tooth begins. Likewise, full contour crowns are virtually undetectable among neighboring natural teeth.

Characterization and firing technique

Fired restorations have a strength of 370 MPa.

The induction furnace CEREC SpeedFire by Dentsply Sirona combines the processes of sintering and glazing in one compact, user-friendly device. The CEREC SpeedFire reaches a maximum heating rate of 300 ° C per minute – no preheating or holding temperatures are necessary. Its induction technology ensures a perfectly homogeneous temperature distribution. Its dimensions make the CEREC SpeedFire a compact device that fits in any practice.

1. Before applying the stain and glaze material, remove all dirt and grease from the restoration.

2. Mix glaze in jar thoroughly with a spatula if separation is seen.

3. Remove desired amount of Celtra Duo Universal Glaze paste from jar to tray.

4. If a different consistency is desired, adjust the consistency by diluting the material with Celtra Duo Universal Stain & Glaze Liquid.

5. Apply a thin layer of glaze material all over the crown surfaces using a staining brush. Make sure not to apply the glaze material either in too thick or too thin of a layer. A thin layer will result in a matte finish. A thick layer can result in a puddling or pooling of a stain.

6. If customization is needed, take a little of the corresponding body and incisal stains and position it on the tray.

7. Dilute if needed and apply it to the crown.Before applying the stain and glaze material, remove all dirt and grease from the restoration.

8. Position crowns directly on the firing pad and fire according to the firing instructions.

9. After the first firing, if the consistency of the glaze was too thin, the restoration may come out under-glazed. If that is the case, apply a thin layer of Celtra Duo (ZLS) overglaze material all over the crown surface using a brush. Once the overglaze is applied, conduct firing procedure according to the Celtra Duo (ZLS) Firing Schedules.