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ePaper created 2018-02-16, 11:17:41 | version 1.38.0
| case report restoration of the edentulous maxilla Fig. 14 Fig. 15 possible to almost playfully recreate the gingiva. The system’s shade guide aids in finding the correct shade. A natural reproduction is based on the anatomical prerequisites. For example, the keratinised gingiva is recreated with light pink materials, as the blood circulation is naturally less in this area, whereas the mucogingival area is imitated using more intensive materials (Fig. 12). With some skill, a 3-D gingiva design is produced and then the bridge is fired. Again, the firing parameters are adjusted and the temperature is lowered slightly. The presented case was also produced in this manner. The recommended firing programme for the first gingiva bake: Start temp. Drying time 403 °C 8 min Temp. increase End temp. 25 °C/min 745 °C Holding time 1 min Vacuum 450–744 °C For the second gingiva bake, the shape was com- pleted and the furnace temperature lowered again by 5 °C (Fig. 13). After this bake, the restoration had a distinct 3-D shape and a very natural appearance. The teeth had a good depth of colour and a warm translucency. Completion While finishing the restoration, full attention was paid to the texture and morphology. The harmonious interchange of raised and depressed areas gave rise to natural-looking reflections. In addition to the edges and curves, the effect of finely detailed struc- tures is not to be under-estimated (microstructure). We therefore intentionally introduced slight irregu- larities in order to produce a certain liveliness. Finally, the restoration was finished with a rubber polisher and then glaze fired (without glaze material). We achieved the required gloss level by manual polish- ing (Figs. 14 & 15). The recommended firing programme for the glaze bake: Start temp. Drying time 403 °C 6 min Temp. increase End temp. 60 °C/min 725 °C Holding time 1 min Vacuum 450–749 °C Conclusion In dental technology, manual skills and optimal materials are essential, but also a profound knowl- edge of materials science and material-specific characteristics is of fundamental value. In particu- lar, when dealing with a complex restoration on a zirconium dioxide framework, correct handling is a major criterion for success. In the case presented, the framework (Zenostar T) and the ceramic veneer (IPS e.max Ceram) successfully harmonised with one another, creating a vibrant interplay of colours. Owing to accurately selected firing parameters, no delamination or late cracks are to be expected._ contact Dr Octavian Fagaras is an expert in oral implanto- logy and runs his own practice in Bucharest in Romania. He can be contacted at office@indent.ro. Milos Miladinov is a dental technician and a licensed photographer. In his dental laboratory, Dental Tech Romania, he specialises in fixed prostheses, all- ceramics and high-end aesthetics. Miladinov can be contacted at dentaltech@dentaltech.ro. Fig. 14: The restoration after the final polish by hand. Fig. 15: The screw- retained resto- ration on the implants. 24 CAD/CAM 4 2017