Strong, fast, and aesthetic: Dentsply Sirona launches new CAD/CAM-fabricated restorations

CEREC Tessera is an advanced lithium disilicate ceramic for the CEREC workflow that can be processed in the CEREC Primemill (Photo credit: Dentsply Sirona)

Dentsply Sirona has announced the introduction of CEREC Tessera Advanced Lithium Disilicate computer-aided design (CAD)/computer-aided manufacturing (CAM) blocks, a new material for CAD/CAM-fabricated restorations for anterior and posterior regions.

High-strength glass ceramics are frequently used by dentists for CAD/CAM-fabricated restorations. The reason is mainly aesthetics — patients usually want restorations looking nearly identical to their natural teeth.

On top of meeting aesthetic demands, the new CEREC Tessera blocks are strong and can accelerate the entire manufacturing process within the chairside workflow by shortening the glaze firing time. According to the dental products manufacturer, a crown can be fired in the CEREC SpeedFire in “4 minutes and 30 seconds”. Compared to other glass ceramics, this represents a time saving across the entire manufacturing process of about 44%. Before firing, the application of a glaze is necessary to achieve the final properties, such as the high biaxial flexural strength of over 700MPa. CEREC Tessera blocks are therefore an attractive option within single-visit dentistry.

The fast-firing time is mainly made possible by the special and new composition of the ceramic made of lithium disilicate and virgilite, a lithium aluminium silicate. The microcrystalline composition with the material virgilite is patent pending in both the US and the EU. The advanced lithium disilicate (ALD) ceramic is characterised primarily by its robust strength and high aesthetics.

During the firing process, new virgilite crystals are formed and embedded in a zirconia enriched glass matrix. Together, these material constituents combine to create a reinforced, high-density restorative material. The dense interwoven crystal composition of CEREC Tessera blocks is key to their strength and helps suppress the presence of microcracks and subsequent crack propagation.

In the CEREC Tessera blocks, the lithium disilicate provides the high tensile strength, while the newly formed virgilite increases the precompression stress. The same microcrystalline composition also contributes to the highly aesthetic and dynamic light refraction, transmission and absorptive properties that mimic the visual vitality of a natural dentition and enables the high aesthetics.

Another advantage of the new material: All CEREC Tessera restorations can be grinded to a fine finish and then be fixed adhesively, for example, with Prime&Bond active and Calibra Ceram. From a wall thickness of 1.5mm, restorations with CEREC Tessera can also be cemented with a resin modified glass ionomer cement.

First users are enthusiastic about CEREC Tessera blocks. Dr Stephanie Holländer, dentist from Frechen, a town in Germany, stated that the short time for glaze firing was a real “game changer”. She was also taken with the simplicity of the whole process: “I didn’t have to make any adjustments — the crowns fabricated in the CEREC Primemill show beautifully finished margins, and the colours available fit perfectly.”

CEREC Tessera blocks are available as of now on the European market, and are indicated for fully anatomical single-tooth restorations in the anterior and posterior regions, including crowns, inlays, onlays, and veneers.

Celtra Ceram

In cases where aesthetics is top priority, Celtra Ceram has now been validated for combined use with CEREC Tessera in the cutback technique. It offers more options, particularly when it comes to highlight subtleties in the translucency and opalescence of the tooth, to create mamelon structures or to achieve an aesthetic match with the adjacent teeth.

This option provides dentists and dental technicians with a versatile ceramic system. Celtra Ceram is a low-fusing system specifically designed for veneering all-ceramic frameworks such as lithium silicates and zirconium oxide.

Both materials were optimally matched to each other by Dentsply Sirona during validation.