A new porcelain system for micro-layering

Case by MDT Andreas Chatzimpatzakis and DDS Manousos Pissadakis

ONE SOLUTION, MULTIPLE NEEDS COVERED

The treatment of young patients with a dental condition that affects the appearance of multiple teeth – like enamel hypomineralisation or hyperplasia – is particularly challenging for the restorative team. Dental practitioners and technicians need to be aware of the fact that the condition often involves a life-long disease burden, which typically goes hand in hand with an immense treatment need and increasingly invasive measures required with advancing age. It is their task to make the situation as bearable as possible for patients by delivering treatment that is very well aligned to their specific aesthetic, functional and financial needs, both in the short and long term.

Whenever all-ceramic restorations seem most appropriate, material and technique selection are particularly important: Protection of the affected teeth from extrinsic influences, the saving of sound tooth structure and the safeguarding of the long-term stability of the restorations are key to success. Depending on the aesthetic expectations of the patient, veneers made of zirconia or lithium disilicate, produced with a minimal vestibular cutback and finished using the micro-layering technique, are a great option. A prime example of an innovative porcelain system specifically developed for this technique is CERABIEN™ MiLai (Kuraray Noritake Dental Inc.). It includes a collection of internal stains and porcelains that fire at just 740 °C. With this low firing temperature and a coefficient of thermal expansion between 9.5~11.0×10-6/K (50 °C – 500 °C), this product is ideal for use with lithium disilicate and zirconia. In addition, it offers impressive aesthetic capabilities: Depending on the specific needs of each case, users can adjust the level of complexity and number of bakes.

CASE EXAMPLE

In the present case of a young female patient with hypomineralisation, it was decided to follow a straightforward approach to restore the maxillary teeth for the time being. For this purpose, we produced a wax-up and transferred it into the patient’s mouth in the form of a mock-up. Following guided tooth structure removal trough this mock-up, an impression was taken. The restorations were designed in full contour, pressed using lithium disilicate-based press ingots (Amber® Press LTW3, HASS Corp.) and cut back slightly in the vestibular area (reduction: 0.3 mm). The selected micro-layering system was applied according to the internal stain technique. The following CERABIEN™ MiLai Internal Stains were used: A little Red in the cervical, and Mamelon 2, Incisal Blue 1 and White in the incisal third. What followed was build-up with CERABIEN™ MiLai Porcelains Tx incisally and LTx proximally; some whitish lines were created with Value Liner 1. Then, I applied a mixture of E2 and ELT1 in the middle and LT1 in the cervical area. After the bake, the restorations were treated with green stones, sandpaper and rubber wheels to pre polish the surface. After glazing with CERABIEN™ ZR FC Paste Stain Clear Glaze, final polishing was carried out.

The whole treatment procedure including tooth preparation, shade determination, veneer production and adhesive cementation is illustrated below.

Fig. 1. Portrait of the patient prior to treatment.

Fig. 2. Enamel defects in the maxilla and mandible.

Fig. 3. Initial clinical situation in the maxilla with whitish-brown discolouration and composite restorations in need of replacement.

Fig. 4. Mock-up in the patient’s mouth.

Fig. 5. Labial reduction through the mock-up: The depth of tooth preparation is controlled by using a depth guide and by marking the created depth grooves with a colour marker.

Fig. 6. Silicon index used to check the space created for the veneers.

Fig. 7. Prepared teeth ready for impression taking and temporization.

Fig. 8. Shade determination for the veneers.

Fig. 9. Pressed lithium-disilicate restorations on the model.

Fig. 10. Appearance of the restorations after internal staining.

Fig. 11. Appearance of the teeth after build-up with CERABIEN™ MiLai Porcelain.

Fig. 12. Final restorations on the model.

Fig. 13. Adhesive cementation procedure carried out for two teeth at once: Isolated teeth and a perfectly dry working field.

Fig. 14. Etching of the tooth structure with phosphoric etchant (K-ETCHANT Syringe, Kuraray Noritake Dental Inc.).

Fig. 15. PANAVIA™ V5 Tooth Primer (Kuraray Noritake Dental Inc.) applied to the etched tooth surfaces.

Fig. 16. Veneers – pre-treated with hydrofluoric acid and CLEARFIL™ Ceramic Primer Plus – filled with PANAVIA™ V5 Paste (Both from Kuraray Noritake Dental Inc.) and placed in the patient’s mouth.

Fig. 17. Restorations after excess removal.

Fig. 18. All eight restorations in place.

Fig. 19. Treatment outcome after two weeks.

Fig. 20. Portrait of the patient taken two weeks after treatment.

CONCLUSION

Repeated dental treatment, increasing invasiveness of the measures, often resulting in early tooth loss: To break the vicious cycle in young patients with enamel defects, it is important to carefully evaluate the treatment need and select the appropriate solutions. As dental technicians, we can contribute to long-term treatment success by using high quality materials and production techniques that allow us to create restorations that last.

The presented material combination and the micro-layering technique are very well suited as they offer the required mechanical and optical properties for high aesthetics and durability. Plus, the risk of complications is low due to the high biocompatibility and the layer of porcelain limited to non-load-bearing areas.

Dental technicians:

ANDREAS CHATZIMPATZAKIS

Andreas graduated from the Dental Technology Institute (TEI) of Athens in 1999. During his studies he followed a program at the Helsinki Polytechnic Department of Dental Technique, where he trained on implant superstructures and all ceramic prosthetic restorations. As of 2000, he is running the ACH Dental Laboratory in Athens, Greece, specialized on refractory veneers, zirconia and long span implant prosthesis. In 2017 Andreas visited Japan where he trained under the guidance of Hitoshi Aoshima, Naoto Yuasa and Kazunabu Yamanda and become International Trainer for Kuraray Noritake Dental Inc..

MANOUSOS PISSADAKIS

Dr. Manousos Pissadakis is a graduate of the National Kapodistrian University Dental School, Athens, Greece. He completed the Master of Science curriculum in Prosthodontics at the School of Dentistry of the Aristotle University of Thessaloniki, Greece. He also holds the ITI Certificate in Implant Dentistry – Foundation and Intermediate Level (ITI Curriculum, ITI section Greece and Cyprus). He has presented at numerous prestigious international conferences, focusing on subjects such as aesthetics, implant dentistry and prosthodontics.