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I 47 meetings _ 9th Ceramics Symposium I cosmeticdentistry 1_2010 ceramic lies at 83 % after 13 years of observation, putting them on par with cast restorations as described in the literature.4 He explained that participating dentists enter their results online on the platform www.csa-online.net and receive an individual, graphic treatment profile. _ZrO2 not always necessary Speaking on the Clinical testing of all-ceramic restorations, Prof Matthias Kern (University of Kiel, Germany) made it clear that ceramics must measure up to the survival rates of metal-sup- ported restorations. The literature demonstrates that ceramic inlays and onlays have a clinical durability similar to that of cast restorations. CAD/CAM restorations demonstrate a longer service life than pressed or laboratory-con- structedrestorations.5 Owingtoitssemi-translu- cency, Al2O3 is particularly well suited for crowns in the aesthetically sensitive anterior dentition. According to Prof Kern, it is thus not necessary to manufacture single crowns from ZrO2. FDPs with ZrO2 frameworks have demonstrated en- couraging results; in observation periods of up to five years, framework fractures occurred rarely, even in multi-unit FDPs. However, some studies described veneering fractures (chipping; Table I). The reason for this is that originally, trusting in the high fracture-flexural strength of the material, ZrO2 frameworks were delicate con- structions, milled out with thin walls onto which thick veneering layers were applied, which be- came subject to tensile force. Prof Kern recom- mended wall thicknesses of no less than 0.8 mm for ZrO2 frameworks and advised designing them anatomically, so that the veneering is supported by the cusps. From the papers submitted for this year’s Research Award in All-Ceramics, the jury selected three studies of equal merit. The presenter of the award thus decided to recognise all three researchers:DrFrankNothdurft(Germany)forhis study Clinical testing of a prefabricated all-ce- ramicimplantbuild-upofzirconiumdioxideinthe posteriordentition,DrAndreasRathke(Germany) for his Invitroexaminationoftheeffectivenessof the dentin bond of ceramic inlays using different lutingconcepts,andFalkBecker(Germany)forhis study Press-on and layering technique, chipping behaviour of all-ceramic anterior crowns. _CAD/CAM workshop reflects practical experience During the concluding CAD/CAM workshop at the Clinic for Dental Prosthetics in Munich, Prof Daniel Edelhoff, Dr Florian Beuer, dentist Peter Neumeier, dental technician Marlis Eich- berger and dental technician Josef Schweiger helpedfamiliariseparticipantswiththefunction- ing of CAD/CAM systems. The clinic is equipped with representative CAD/CAM systems (C.O.S., 3M ESPE; Cercon, DeguDent; DigiDent, Girrbach- Amann; etkon, Straumann; Everest, KaVo; inLab, Sirona Dental Systems; Lava, 3M ESPE; Procera, Nobel Biocare; ZENOTEC, Wieland), which are used in scientific projects and for practical work in patient treatment. In terms of the achievable quality and preci- sion of fit of the milled all-ceramic frame-works, Prof Edelhoff emphasised that these are of a high level in every respect. Schweiger pointed out that the computerised milling systems for all-ceramic restorations employ various grinding strategies thatareespeciallydesignedfortheoriginalblanks of the manufacturer. ZrO2 frameworks that were manufactured in manual copy-milling processes (pantograph) had a worse fit and a critical struc- ture, according to Schweiger. Prof Beuer and Schweiger demonstrated a new way to avoid veneering fractures: sinter veneering (Fig. 6). In this, single veneer structures of feldspathic ceramic are computer milled and sintered onto the ZrO2 framework._ Editorial note: A complete list of references is available fromthepublisher. Fig. 6_The feldspathic veneer, ground with CAD/CAM, was ceramic sintered to the ZrO2 crown framework. (Photograph courtesy of Josef Schweiger, Germany) Manfred Kern,Wiesbaden,Germany Society for Dental Ceramics (Arbeitsgemeinschaft für Keramik in der Zahnheilkunde e.V.) E-mail:info@ag-keramik.de Website:www.ag-keramik.eu cosmeticdentistry _contact Fig. 6