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works was evident in the excellent milling results obtained on the occlusal and palatal surfaces and at the incisal edge (Fig.5). Customising the framework Once the milling was com- pleted, the framework and the sinter support structure were separated from the disc. In the next step, the unsintered bridge was customised with colouring liquids using the infiltration tech- nique.TherangeofZenostarColor Zr liquids is perfectly suited for this purpose, as they are supplied in the standard shades of the A–D shade guide. Five Effect shades are available for further customisa- tions.WeusedZenostarColorZrin shades A2 and A3 as well as the grey-violet Effect shade. In order to render the infiltra- tion of the individual liquids visi- ble,thevirtuallycolourlessliquids were mixed with a visualizer (Zenostar VisualiZr). First, the in- terior surfaces of the crowns and the basal surface were infiltrated; followed by approx. 1 mm of the cervical margin, the fissures and thecentralareasofthepalatalsur- faces. Infiltration of all these as- pects was achieved with Zenostar Color Zr A3 mixed with yellow Zenostar VisualiZr (Fig. 6). After that, the dentin area up to the incisal third was infiltrated with shade A2 mixed with red VisualiZr liquid. The incisal area of the anterior teeth and the cusps of the poste- riors were customized with a di- luted version of grey-violet Effect shade and Zenotec Color Opti- mizer mixed with blue VisualiZr liquid (Fig. 7). It is essential to use a separate brush for each shade. After having been allowed to dry for two hours, the framework was sintered in the Programat S1. After the sintering process, the restoration exhibited an excellent accuracy of fit, without nthe need for any adjustments by grinding, e.g. on the insides of the crowns. The advantages of the translucent zirconium oxide became obvious at this stage. Owing to the colour- ingliquids,thecervicalanddentin areas were beautifully accentu- ated. The incisal areas exhibited a slight greyish-translucent sheen, which should facilitate the subse- quentlayeringprocedure(Figure8 shows the smooth transition of the shades). The simulation in Figure 9 demonstrates how difficult it would have been for us to achieve the desired tooth shade if we had used opaque white zirconium oxide for the framework. Despite the high translucency of the zirco- nium oxide, the titanium abut- ments did not show through the framework. Individual framework refinements Anoptimumaestheticoutcome is only achieved if the restoration exhibits ideal optical properties. A controlled brightness value, adequate saturation and trans- lucency and minimised light re- flection are essential to achieve a pleasing aesthetic outcome. If these parameters are not met, the result will never be satisfactory, even if the restoration is veneered with ceramics. The result would simply be a restoration that looks goodonthemodelbutappearstoo bright in the mouth. Staining the zirconium oxide prior to sintering is the first meas- ure to control the light reflection effects.Applicationofalineristhe second measure. The bridge was veneered with IPS e.max Ceram. As the framework already exhib- ited a pleasing basic shade, we applied a mixture of IPS e.max Ceram ZirLiner Clear and Incisal (70:30). ZirLiner Incisal reduces the light reflection of zirconium oxide; alternatively Liner 4 may be used. In order to mix the liners, IPS e.max ZirLiner Build- Up Liquid was added. The result wasamixturewithapleasingcon- sistency that would ensure an even coating. After the firing process, the restoration exhibited a homogeneous surface and an adequate level of fluorescence. For the foundation firing of large restorations, we prefer the layer- ing technique rather than the sprinkle technique. The layering technique provides better ad- hesion and optical effects (wash firing: Deep Dentin A2, A1, DA2, A1 and T-Neutral) (Fig. 10). The indi- vidual vestibular surfaces can be easily veneered. Fig. 8: After sintering: smooth colour transition and ideal basic shade for completing the bridge.—Fig. 9: Com- parison between white opaque zirco- nium oxide (superimposed simulation at the top margin) and the Zenostar Zr framework.—Fig. 10: After the liner and foundation firing…—Fig. 11: ...the vestibular anterior surfaces were ve- neered individually.—Fig.12: After final firing: the monolithic crowns did not appear brighter than the veneered crowns.—Fig. 13: Finished bridge: har- monious shade effects and homoge- neous surface texture.—Figs. 14 & 15: The cemented bridge pleases with its beautiful natural appearances and meets the patient’s functional and aesthetic expectations. Dental TribuneAsia Pacific Edition | 4/201614 TRENDS&APPLICATIONS PRINT DIGITAL EDUCATION EVENTS The DTI publishing group is composed of the world’s leading dental trade publishers that reach more than 650,000 dentists in more than 90 countries. VISIT US DURING AT BOOTH 6N-17IDEM 2016 AD 8 9 10 11 12 13 14 15 8910 111213 1415