A precision workflow without compromise for ceramic reproduction

A 42-year-old patient presented at the dental practice because he was unhappy with the appearance of his esthetic zone. During clinical examination, a deficient VMK crown with deficient margins was observed on tooth 11. The morphology of the crown did not blend in with the overall appearance and the ceramic veneering seemed unnatural. There was an incisal fracture on tooth 21, with the fracture zone covered only by filling composite. Following in-depth consultation, it was agreed that tooth 11 should be restored with an all-ceramic crown and tooth 21 with a minimally invasive veneer. The substructures were each to be pressed from the zirconia-reinforced lithium disilicate VITA AMBRIA to achieve a true-to-shade, precise and lifelike foundation for individualization, using the universal veneering ceramic VITA LUMEX AC in a matching shade.

Following local anesthetic, both central incisors were prepared or re-prepared accordingly. This was then followed by in-depth tooth shade determination, using both the digital VITA Easyshade V spectrophotometer, and an analog approach with VITA Linearguide 3D-MASTER. In doing so, the shades of the prepared tooth were also determined consistently, and the clinical situation documented photographically with the selected shade tabs, both with and without a polarization filter. Due to discoloration of the prepared tooth and crown (tooth 11), VITA AMBRIA T 1M1 was selected to compensate for this with more brightness. On the preparation surface of tooth 21 that was not discolored, VITA AMBRIA T 2M2 was used in line with the identified tooth shade. Impressions were taken of the preparations and a master model fabricated in the laboratory on this basis. The substructures of the restorations were fabricated using wax on the plaster dies. After separate spruing, investing and burning out, both substructures were pressed one after the other. As there was almost no reaction layer, divesting was quickly completed, revealing homogenous surfaces and sharply tapering restoration margins.

The washbake was carried out on the substructures using highly fluorescent VITA LUMEX AC POWERWASH to harmonize the varying translucent effects of the different substructures with the required basic tooth shade. This ensures that the shade intensity of the veneering ceramic is not lost, even with translucent substructures such as the veneer on tooth 21. The washbake on the more delicate veneer substructure was carried out using the more chromatic material POWERWASH LL2. For the crown substructure on the discolored prepared tooth (tooth 11), the washbake was carried out using the less chromatic material POWERWASH LL0. The more chromatic material LL1 was only used on the margins not directly supported by dental structures and on the incisal edge. After harmonization at depth in this way, it was possible in just a few steps to layer the dentin core and the enamel areas so that they would remain stable during firing. It was also possible to finalize both restorations in the same way.

After successful clinical try-in, both restorations were permanently inserted using the VITA ADIVA FULL-ADHESIVE LUTING SET. In doing so, a translucent composite was used for the veneer and a white composite for the crown to facilitate masking. Thanks to the multi-faceted VITA LUMEX AC veneering ceramic, which was matched to the specific tooth shade, a complex case could be solved on true-to-shade and lifelike structures made from the precision press ceramic VITA AMBRIA. By applying a wafer-thin layer at depth of the highly fluorescent POWERWASH materials, it was possible to harmonize the shade effect by compensating for the different prepared tooth shades and substructure translucencies. An efficient workflow was guaranteed, thanks to the user-friendly material stability and the outstanding firing stability of the ceramic materials. The homogenous ceramic surface was easy to finish and polish, and to ultimately simulate the complex light refraction of the natural hard tooth substance. Both patient and practitioner were fully satisfied with the final result that did not require any compromises.