Kostia Vyshamirski

Case by Kostia Vyshamirski, DT

KATANA™ Zirconia YML AND CERABIEN™ MiLai

Virtually every patient in need of restorative treatment desires functional restorations with an aesthetic appearance. However, the individual expectations and needs may be very different depending on the clinical situation (state of the natural tooth structure, parafunctional behaviour, periodontal health etc.), the patient’s financial resources and personal preferences. A versatile material combination fulfilling many different needs and desires is KATANA™ Zirconia YML finished using micro-layering with the new CERABIEN™ MiLai (both Kuraray Noritake Dental Inc.).

This system supports low invasive preparations due to a favourable minimum wall thickness of the merely monolithic multi-layered zirconium oxide prosthesis and a minimal thickness of the porcelain layer in the aesthetic zone. Moreover, the high strength zirconium oxide prosthesis combined with only a very thin layer of porcelains makes this technique extremely useful in patients with parafunctional habits like bruxism. Last but not least, consisting of a carefully compiled selection of internal stains and porcelain shades, CERABIEN™ MiLai supports the creation of individual 3D shade effects that mimic those of natural teeth even when space is limited. The following case example reveals how this is possible.

INITIAL SITUATION

The patient presented with concerns related to both function and appearance. During the diagnostic phase, it was determined that increasing the vertical dimension of occlusion (VDO) and creating a wax-up in the new jaw position would be necessary to improve both the occlusion and the aesthetic appearance of the smile.

Fig. 1. Intraoral scan of the maxillary teeth revealing severe tooth wear.

Fig. 2. Intraoral scan of both jaws confirming the need for an increase of the VDO.

Fig. 3. Intraoral scan: Occlusal view of the maxillary teeth.

TREATMENT PLANNING AND COMPUTER-AIDED DESIGN

Following the approval of the wax-up, the treatment plan was created. It consisted of restoring the four anterior incisors with zirconia crowns and performing direct composite restorations on the posterior and lower teeth. To conserve as much of the healthy tooth structure as possible, the space created was aligned to the required wall thickness of the planned restoration (framework + micro-layer of porcelain in the vestibular areas only). Following an aesthetic analysis, the crowns were designed with a minimal vestibular cutback. This was due to the patient’s functional problems, which would increase the chipping risk in case of using a more heavy cutback design with a thicker, more conventional porcelain layer. KATANA™ Zirconia YML offers exceptional aesthetics, requiring only a 0.3 mm reduction for the porcelain to achieve natural results. Therefore, it was the logical material choice for this specific case.

Fig. 4. Minimally invasive preparations for the crowns.

Fig. 5. Occlusal view of the preparations.

Fig. 6. Aesthetic analysis – a crucial step for achieving the desired new smile.

Fig. 7. Frontal view of the crowns in their final cutback design.

Fig. 8. Lateral view of the crowns in the CAD software.

CROWN PRODUCTION

Immediately after milling, the zirconia surface was treated with effect liquids. This kind of pre-sintered characterization helps enhance the characteristics of zirconia restorations. In the presented case, orange stain was applied to the cervical area, while a blue stain was used at the incisal edge. In addition, a white opaque liquid was applied to the inner surface of the central zirconia crowns to block out any discolouration from the underlying tooth structure. Following final sintering, the vestibular layer of porcelain was built up with CERABIEN™ MiLai using a combination of internal stains and porcelain micro-layering. After morphological adjustments and surface polishing, the restorations were completed by applying CERABIEN™ ZR FC Paste Stain and Glaze. Final polishing was then performed to enhance the natural appearance of the surfaces.

Fig. 9. Effect liquids applied to the cervical and incisal areas of the crowns.

Fig. 10. Treatment of the central incisor crowns’ inner surfaces.

Fig. 11. KATANA™ Zirconia YML framework after sintering.

Fig. 12. CERABIEN™ MiLai Internal Stains and Porcelains.

Fig. 13. Prepared vestibular surfaces ready for application of the internal stains.

Fig. 14. Application of 0.2-0.3 mm layers of CERABIEN™ MiLai porcelain: CCV2 for the cervical area, LT1 – Creamy Enamel for the main body and luster, LTX at the incisal edge.

Fig. 15. Frontal view of the final restorations on the model.

Fig. 16. Lateral view of the final restorations on the model.

Fig. 17. Polished and glazed palatal surfaces of the crowns.

FINAL OUTCOME

The finalized restorations showcase great details, crafted with CERABIEN™ MiLai internal stains and porcelains. The result are natural-looking restorations. An additional benefit of using zirconia as a restorative material is its excellent compatibility, which is evident in the healthy gingival conditions.

Fig. 18. Restorations in place.

Fig. 19. Natural-looking restorations in the patient’s mouth.

Clinical case by Kostia Vyshamirski, DT

Digital technologies for computer-aided imaging, planning, design and manufacturing are valuable tools that support dental technicians in their daily work. Combined with traditional approaches, those digital tools allow us to assess, shape, and finally meet or even exceed patient expectations. The case below is a perfect example: We produced 20 natural bleach restorations made of KATANA™ Zirconia YML and CERABIEN™ ZR Porcelains and of Noritake Super Porcelain EX-3 (Kuraray Noritake Dental Inc.), respectively.

INITIAL SITUATION

The aim was to create a new white, still natural smile. It was decided to replace the old crowns in the maxilla and to create a wider and brighter smile by adding laminate veneers in the maxilla and mandible.

Fig. 1. Initial clinical situation.

DIGITAL SMILE DESIGN AND DIAGNOSTIC WAX-UP

Digital smile design and a diagnostic wax-up are great tools for analysing and planning a new smile. Intraoral scans and portrait photographs of the patient served as the basis for the development of the ideal proportions and shapes. Once the virtual designing of the new restorations was completed (software: exocad DentalCAD), the wax-up models were printed. By transferring the wax-up into the patient’s mouth via an index or matrix, it is possible to test and assess the outcome intraorally. In this step, aesthetic and functional analysis should be the priority.

Fig. 2. Digital smile design based on an image.

Fig. 3. Computer-aided waxing up in the maxilla based on the smile design.

Fig. 4. Completed virtual wax-up for the maxilla and mandible.

Fig. 5. Wax-up transferred into the patient’s mouth for functional and aesthetic analysis.

Fig. 6. The planned new bright smile.

ALVEOLAR PRINTED MODEL

Precise and functional models are essential for the production of accurate, aesthetic restorations in the laboratory. The model builder software SHERAeasy-model (SHERA) and a 3D printer (ASIGA MAX UV, Asiga) were used to produce solid models and alveolar models with full gingival information and removable dies.

Fig. 7. Alveolar models printed in gingiva and tooth colours.

Fig. 8. Printed models with articulator holding plates and removed dental elements.

REFRACTORY DIE DUPLICATION AND ARTICULATION

The refractory die technique allows for the production of extremely thin-walled restorations and hence supports minimal tooth structure removal. For this reason, the approach seems best suited for all previously untreated teeth without major defects. The printed dies were duplicated in the refractory die material before mounting the models in the articulator for a transfer of the maxillomandibular relations.

Fig. 9. Process of duplicating printed dies in the refractory material.

Fig. 10. Articulating the models.

PRODUCTION OF THE RESTORATIONS

To achieve the best results, it is essential to select the best material for each specific situation. For the production of the crown frameworks used to restore the six maxillary anterior teeth, KATANA™ Zirconia YML in the shade NW appeared to be the ideal option. Their intaglio surfaces were treated with Esthetic Colorant (Kuraray Noritake Dental Inc.) in the shade OPAQUE to prevent a shining through of the discolourations found on some of the prepared teeth. After sintering of the frameworks in a high-temperature sintering furnace (Nabertherm) at 1,550° C, CERABIEN™ ZR porcelains were applied as illustrated below. For the creation of natural effects inside the restorations – i.e. between the layers of porcelain –, we use the internal stain technique (ILS). This procedure is very predictable and fast. Each step during porcelain build-up and staining was recorded with photos to monitor the entire process and to capture all information on the individual protocol steps. The porcelain veneers (Super Porcelain EX-3, Kuraray Noritake Dental Inc.) were produced on the refractory dies to restore the premolars in the maxilla and central incisors to second premolars in the mandible.

Fig. 11. Refractory dies and zirconia frameworks on the model.

Fig. 12. Wax-up on the model with removable dies.

Fig. 13. KATANA™ Zirconia YML frameworks on the model.

Fig. 14. Opacity control with CERABIEN™ ZR Opacious Body OB White to optimise brightness.

Fig. 15. Application of CERABIEN™ ZR Body NW0.5 to restore the cores of the crowns using a silicon index.

Fig. 16. CERABIEN™ ZR porcelains E1 and LTX applied to create translucency at the incisal edge.

Fig. 17. Prepared surface ready for internal stain application.

Fig. 18. Creation of mamelons and incisal effects with CERABIEN™ ZR internal stains.

Fig. 19. Adaptation of the incisal third with a mamelon mixture of internal stain shades (white, mamelon orange and bright).

Fig. 20. Outcome of the internal staining procedure.

Fig. 21. CERABIEN™ ZR Luster application using the Interchangeable Build-up Technique, application of CCV1 in the cervical area.

Fig. 22. CERABIEN™ ZR porcelains ELT1 used for the core, LTX for the incisal area and ELT3 for the ridges.

Fig. 23. Restorations finished by carving, hand polishing and a self-glaze bake.

Fig. 24. Layering map summarizing the porcelain layering procedure.

FIT ASSESSMENT AND TRY-IN

When the production process was complete, the restorations were placed on the solid models (printed master casts). This step is very important to validate the passive fit and contact points of each crown and veneer. Afterwards, it was time to try-in and check all the restorations intra-orally.

Fig. 25. Final restorations ready for fit assessment.

Fig. 26. Maxillary restorations: Checking of the passive fit and contacts on the model.

Fig. 27. Mandibular restorations: Checking of the passive fit and contacts on the model.

Fig. 28. Intra-oral try-in of the crowns.

DEFINITIVE PLACEMENT AND FINAL OUTCOME

Refractory ceramic veneers were cemented via an adhesive protocol using a resin-based composite. Opaque glass ionomer cement was used to cement the zirconia crowns.

At the recall about one month after restoration placement, we saw amazing gum conditions and a happy, healthy and beautiful smile!

Fig. 29. Image taken right after definitive placement of the crowns.

Fig. 30. Nice pink-and-white aesthetics achieved with the all-ceramic restorations.

Fig. 31. Amazing gum conditions found one month after restoration placement.

Fig. 32. Happy, healthy and beautiful smile.

Fig. 33. The new smile exceeds expectations.

Case by Kosti Vyshamirski

A male patient (47 years of age) presented to his dentist with severe damage to his teeth. His main request was to increase aesthetics, to achieve a more pleasing envisaged aesthetic area. A side request was to achieve a ‘whitening but natural look’. This was achieved by using a lighter colour palette of zirconia and porcelain materials.

The final result was achieved through the creation of a wax-up, followed by a mock-up, provisional restoration and finally adhesive bonding of the zirconia crowns.

INITIAL SITUATION

Fig. 1. Initial situation. Male patient (47 years of age).

Fig. 2. Planning the new smile according to patient’s aesthetic and functional parameters.

Fig. 3. Mock-up in place to check the new look in the patient’s mouth.

Fig. 4. KATANA™ Zirconia YML shade A1 crowns with labial cutback after milling.

Fig. 5. Crowns after sintering on the plaster model.

Fig. 6. Noritake CERABIEN™ ZR porcelain layering map.

Fig. 7. Finishing the labial surface using both polishing and selfglaze. On the palatal side of the crowns only CERABIEN™ FC Paste Stain stains and glaze were used for finishing. To aid in optimisation of the soft tissue condition the palato-cervical and near proximal areas were polished.

Fig. 8. Finished crowns on the plaster model.

Fig. 9. Try-in using PANAVIA™ V5 White try-in paste, to confirm the proper appearance. For the final adhesive cementation PANAVIA™ V5 White has been used.

FINAL SITUATION

Fig. 10. Situation after seven months. The result is aesthetically pleasing and the gingival condition excellent.

Fig. 11. Recall after 1.5 years.