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This is where a block gets its name

August 8th

The specimen carousel in the lapping machine

Sample blocks of all CAD/CAM materials are taken at regular intervals. These are put through their paces before the goods can go to customers.

A diamond wire saw is used to make specimens from the blocks. Whirring away, it first saws the block into slices, which are then broken down into sample strips. During sawing, fine grooves are produced on the surface, which would act like breakpoints in the flexural strength test.

According to current regulations, these grooves are smoothed in order to obtain correct results for the material properties. The lapping machine is used for this purpose. In the specimen receptacles, which look like the sprocket of a bicycle gearshift, up to 12 test strips can fit at the same time. The heavy cover is closed. 15-kilo plates with an abrasive surface and polishing fluid come into contact with the delicate test strips from above and below. With the gear drive over the centrally rotating axis, the specimen carousel begins to rotate around itself and around the central drive axis.

Depending on the material, the illustrious polishing process is completed after three to 15 minutes. Now all specimens have a smooth surface and comply with the prescribed ISO standard. The test strips are gently removed and cleaned with water.

It is a lot of work to mercilessly secure this now to the end of the experimental setup and destroy it with the defined force of a bolt in the bending-to-failure test. This is a critical step in quality assurance, Only if the bending strength corresponds to the required material properties, is the sustainable use of VITA materials in the patient's mouth, and the long-term satisfaction of customers, possible.

VITA ENAMIC®
Up to 12 test strips fit in the specimen receptacle.
Up to 12 test strips fit in the specimen receptacle.
Up to 12 test strips fit in the specimen receptacle.
Quality is a source of pleasure.
Quality is a source of pleasure.
Quality is a source of pleasure.
The test strips are carefully inserted.
The test strips are carefully inserted.
The test strips are carefully inserted.

Veneer made from VITA ENAMIC impresses with natural shade effects

Dr. Bernhild Elke Stamnitz

Dr. med. dent. Stamnitz, Bernhild-Elke

Author

    • Since 2004 private dental practice in Langen, Germany and CEREC user
    • Internationally certified CEREC trainer (ISCD)
    • International speaker for VITA Zahnfabrik
    • Memberships in DGCZ and AG ceramics, among others
    • Numerous publications on the subjects of CEREC and digital dentistry

            Patient case: Veneer made from VITA ENAMIC®

            The 28-year-old patient presented at our practice in Langen with an inadequate all-ceramic restoration on tooth 21 (Fig. 1). An inadequate restoration edge had already led to marginal gingivitis. Moreover, the patient was unhappy with the shape and shade of the restoration and wanted a less obvious solution to better match the shape of the adjacent tooth (tooth 11). A decision was taken to remove the existing veneer and to fabricate a new restoration using the VITA ENAMIC hybrid ceramic.

            Preparations

            Shade determination was carried out using the VITA Easyshade Advance 4.0 shade-taking device (VITA Zahnfabrik, Bad Säckingen, Germany). A VITA ENAMIC blank was selected in the shade 1M1-HT. VITA ENAMIC is available in two levels of translucency, HT (HT = highly translucent) and T (T = translucent), each of which is available in the five VITA SYSTEM 3D-MASTER shades 0M1, 1M1, 1M2, 2M2 and 3M2. The manufacturer recommends the HT material variant for veneers. 

            As treatment progressed, the existing restoration was removed and the caries at the vestibular margin excavated (Fig. 2). Optical impression-taking was then carried out using the CEREC Omnicam from Sirona. 

            Virtual design

            The virtual, three-dimensional model was imported and trimmed in the CEREC V 4.2 software (Sirona Dental GmbH, Wals, Austria), Fig. 3. The preparation margin was then defined on tooth 21 (Fig. 4). In order to transfer the shape of tooth 11 as desired onto the tooth to be restored, the copy line was drawn and reversed (Fig. 5). Based on the collected data, the software automatically generated a suggested design (Fig. 6 and 7). This was modified slightly at the margins before completing virtual positioning in the selected blank (block size EM-14 measuring 12 x 14 x 18 mm), Fig. 8. 

            Fabrication

            The VITA ENAMIC veneer was then milled at normal speed using the CEREC MC XL Premium milling unit. According to the information provided by the manufacturer, VITA ENAMIC also supports fast milling mode. Due to its special structure comprised of a ceramic and polymer network, machining the material results in less milling tool wear than in the case of other CAD/CAM ceramics. Other benefits include that the material can be milled more thinly, particularly in edge areas, without any fractures at the margins. This reduces the workload during finishing. 

            Finishing and placement

            Removal of the sprue was then followed by try-in of the veneer in the patient's mouth (Fig. 9). To create a surface texture, the VITA ENAMIC Polishing Set clinical was used. In order to replicate the adjacent tooth, only the incisal edge and the surface were made a little less even. High-gloss polishing then followed. Glazing can be performed using light-curing stains. Different to other ceramics a firing is not required at all with VITA ENAMIC.

            Thanks to the natural shade effect of the hybrid ceramic veneer, the patient was immediately delighted. Figure 10 shows the result. The natural translucence along the incisal edge was possible because the material can be milled to create a very thin layer. The wall thickness in the marginal area can be reduced to 0.2 mm. Before final cementation was carried out, the shade effect was evaluated using try-in pastes from the Variolink Veneer cementation system (Ivoclar Vivadent, Schaan, Liechtenstein). Placement was then carried out in a relatively dry environment using Variolink Veneer in the shade HV+1. 

            For daily use

            VITA ENAMIC has proven itself to be an innovative material in our practice. It is often used instead of silicate and oxide ceramics. This is due on the one hand to the effective processing that it supports. However, the hybrid material can also be milled to a very thin layer. This allows us to carry out preparation in a manner that is gentle on tooth substance and thus remain true to our philosophy of retaining as much healthy tooth substance as possible. Many patients also report that the restoration feels comfortable in their mouths, in a similar way to natural dentition.

            Fig. 1: Initial Situation.
            Fig. 1: Initial situation.
            Fig. 1: Initial Situation.
            Fig. 2: Tooth 21 following removal of the existing restoration and excavation of the caries.
            Fig. 2: Tooth 21 following removal of the existing restoration and excavation of the caries.
            Fig. 2: Tooth 21 following removal of the existing restoration and excavation of the caries.
            Fig. 3: Digital model of the upper jaw in the CEREC V4.2 software, generated using the CEREC Omnicam.
            Fig. 3: Digital model of the upper jaw in the CEREC V4.2 software, generated using the CEREC Omnicam.
            Fig. 3: Digital model of the upper jaw in the CEREC V4.2 software, generated using the CEREC Omnicam.
            Fig. 4: Definition of the preparation margin.
            Fig. 4: Definition of the preparation margin.
            Fig. 4: Definition of the preparation margin.
            Fig. 5: Reversal of tooth 11.
            Fig. 5: Reversal of tooth 11.
            Fig. 5: Reversal of tooth 11.
            Fig. 6: Design proposed by the software.
            Fig. 6: Design proposed by the software.
            Fig. 6: Design proposed by the software.
            Fig. 7: Completed veneer design.
            Fig. 7: Completed veneer design.
            Fig. 7: Completed veneer design.
            Fig. 8: Positioning in the virtual blank.
            Fig. 8: Positioning in the virtual blank.
            Fig. 8: Positioning in the virtual blank.
            Fig. 9: Try-in in the patient's mouth.
            Fig. 9: Try-in in the patient's mouth.
            Fig. 9: Try-in in the patient's mouth.
            Fig. 10: Final result with natural shade effect in the patient's mouth.
            Fig. 10: Final result with natural shade effect in the patient's mouth.
            Fig. 10: Final result with natural shade effect in the patient's mouth.

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            All topics on the VITA Calendar 2018
            All topics on the VITA Calendar 2018

            VITA ENAMIC®

            redefines load capacity.
            VITA ENAMIC is the first dental hybrid ceramic in the world with a dualnetwork structure.

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